ApparelEngineeringIndustrialEngineeringMethodsforApparelIndustry

By

AKHILJK

Copyright©2016AkhilJkAllrightsreserved.Noreproduction,copyortransmissionofthispublicationmaybemadewithoutwrittenordigitalpermissions.

Nodiagrams,illustrations,chartsorsuchdigitalworksinthispublicationmaybereproduced,copiedortransmittedsavewithoutpriorwrittenpermissions.Butalldatacanbeusedforindustryproductivityenhancements.

DBAofOn-DemandPublishingLLC,Amazongroupofcompanies,Seattle,Washington,U.S.ISBN-13:978-1515127123ISBN-10:1515127125jkakhil@msn.com

Affirmation

Therearenocopyrightedmaterialsusedinthispublication,allthedigitalmaterialsusedsuchasphotographs,charts,diagramsetc.arepreparedbytheauthorandsupportingpersonalsexclusivelyfortheuseoftheauthor,orpubliclyavailablematerialwhicharelabelledforreuseorreusewithmodificationsonly.Weextendallcreditsofsuchmaterialstoitsoriginalownersitself.

ContentsandtheoriesincludedinthispublicationislicensedunderaCreativeCommonsAttribution-NonCommercial-NoDerivatives4.0InternationalLicense.Andareavailableforeducationalandprofessionaluse.Allthetheorieshavebeenprofessionallytestedandpracticedforaccuracy,eventhoughwedonotguaranteeanyaccuracyasthesearetestedunderdifferentfactories.Westronglyrecommendatrialrunshouldbeconductedforyourfactorybeforegoingforamassintroduction,andthereitmayneedslightormajorchangesintheformulasandmethodsaccordingtotheMan,MachineandMethodused.

ThisworkislicensedundertheCreativeCommonsAttribution-NonCommercial-NoDerivatives4.0InternationalLicense.Toviewacopyofthislicense,visithttp://creativecommons.org/licenses/by-nc-nd/4.0/.

Preface

Theideabehindthisbookisemergedfromtheauthor’sneedforasuitabletextbookfortheApparelEngineeringtosupportthelectureatIndia’sLeadingVocationalCollege’stosolvethedifficultyinavailabilityofrightmaterialsforthesubject.MostoftheIndustrialEngineeringsessionswerebeentakenusingtheMechanicalEngineeringtheoriesconvertedtoindustry,alsofromtheneedofindustrialEngineerswhoareworkinginindustries.ItneedalotofbookstousefortheApparelEngineeringsessiontobetaken.HopethisbookwillserveasasinglereferencetothenewlyarousedsessionintheFashion

industryandalsointroducingtheterm“ApparelEngineering”totheworldforthefirsttime.

ApparelEngineeringisatermtoexplaintheindustrialengineeringactivitiestobeusedinApparelProductionprocess,thiswillincludemethodstoreduceMan,MachineandMaterialwastageintheApparelProductionprocess,itincludesselectionofrighttoolsandmachines,trainingtotheoperatorsforqualityandfastproduction,materialmanagement,ergonomicstouseinapparelindustry,methodsdevelopmentandadvancedproductionplanninganddevelopmentofmethodstudyandWorkstudyapplicationsinproductionprocess,Linebalancingtoproducthandling.

Thewholebookletiscapsuledtoeasyknowledgebyreducinglongtheories.MaximumrealtimedatafromindustryareusedtogenerateandexplainthecalculationssothatthemethodscaneasilybeadaptedtoindustriesbytheirindustrialEngineers.

Usingownoriginalcompiledteachingmaterials,andwiththesupportofmanycurrentpractitionerswithinthefashionproductionindustry,itwassetouttodevelopthestructuredbookforreferencetotheApparelEngineersandotheracademiciansintheFashionProductionindustry.Allmaterialcontainedinthisbook,otherthanwherespecificallyreferenced,comesfromoriginalsourcesorresearchfromvariousresourcesandindustrypracticingmethods.Thecalculationsandmethodsexplainedhereareguidelinesanditcannotbeguaranteedsuccessalltimes,astheApparelEngineeringissituationbasedandchangesaccordingtoproduct,machines,placeandoperatorsconditions,butmostofthetheorycanbeappliedinmajorsituationsafterdoingaproperresearchofthesituationapplicability.Aproperstudyaboutyourindustrybasedontheexplainedsituationsmaybenecessarywhileapplyingthesemethodsintherunningproductionfloor.

Iwouldliketopersonallythankallthosepeoplewhohavehelpedmakewritingofthisbookpossible.DedicatedtoAllApparelEngineersoftheworldReg,AkhilJKContents

1.Introduction1-14a.Waste1b.History2c.ApplicationofAEinRMG2d.BasicTerms3e.SewingMachine4f.MachineBeds5g.FeedMechanism6

2.FacilityLayoutandMaterialPlanning15-46a)MaterialFlowsystem16b)PlantLayouts19c)ProcessChart24d)MovementandFlowactivities31e)Spacerequirement37f)Factorylayout37g)MaterialHandling41h)EconomicsofMaterialHandling46

3.ProductionSystems47-58a)MakeThrough47b)Sectionorgroupsystems48c)PBS49d)Synchrosystem51e)QuickResponseSystem54f)Modular55

4.Capacityplanning59-68a)CapacityUtilisation64b)CapacityRequired65c)WorkCentreLoad66

5.MarkerPlanning&cutting69-90a)FabricWidth70b)Graindirection71c)Markerplanning72d)Fabriclossoutsidemarker74e)Processingoffabricfaults76f)Markerutilisation81g)Cutorderplanning82h)Costing87i)Fabricreconciliation90

6.Workstudy91-114a)Procedure91b)Productivity99c)Micromotionstudies102d)

OperationBreakDown103e)SkillMatrix106f)Threadconsumption107g)LostTime110h)Productionstudy111

7.WorkMeasurement115-140a)Techniques116b)BreakingJobintoElements118c)MeasuringwithStopwatch120d)Performancerating120e)Allowances124f)Activitysampling128g)CycleChecks131h)StandardTime133i)PMTS135

8.IndustrialErgonomics141-148a)MSDS142b)Ergonomics142c)PrinciplesofMotionEconomy144d)WorkingArea145

9.ProductionPlanning149-176a)PlanningProcess149b)RoleofSAM150c)LinePlanning151d)CapacityPlanning152e)LineBalancing154f)WIP157g)SchedulingOrders159h)ManufacturingLeadTime162i)LoadLevelling165j)SchedulingBottlenecks166k)OperationScheduling170l)ProductionReporting173m)Follow-ups173

10.Jobevaluation&Compensation177-186a)Process178b)SimpleRating178c)JobGrading179d)Designingwagestructure181e)Incentiveplan182

FirstEditionPublishedonMarch2016Historyofdevelopment,applicationsofAE,Terms,SewingMachine,Feed..

1Introductions

GarmentEngineeringGarmentengineeringisthesystematicstudyofidentifyingtechnicalwastagesduringthegarmentmanufacturingprocessandtakecorrectivestepstoremovethewastetoimproveproductivity.

Itismostconfusedwithindustrialengineering,garmentengineeringmethodsaredesignedtosuittheneedsofanapparelindustryasitisacombinationofdesigns,machine,fabric,trimsandhumanefforts.Theapplicationofgarmentengineeringcanbestartedfromthedesignroomtillretailmarket.WhereasIndustrialEngineeringisdeliberatelyapplicableintheproductionflooronly.Garmentengineersalsouseindustrialengineeringtoolsintheproductionfloorhencemakingitasapartofgarmentengineeringincertaindepartmentsonly.IndustrialengineeringisdevelopedbasedonthemechanicalproductionproceduresandinmostcasestheseareusedinRMGforsettingmachinesandother,butinmajorcasesthewrongusagecreatesexcessburdeninproductionlossandunexpectedbottlenecks.

GarmentEngineeringisdevelopedfromthethoughtofwastereductionisnotonlyrequiredinproductionwhereareasystematicmethodisalsorequiredinotherdepartments.Therearemanymethodsinuseatdifferentdepartmentsbutnotyetstandardized.Thisbooktriestocombinemostofthemethodsusediningarmentindustrytoreducewasteandtogetmaximumproductivityandoutputinalldepartmentsstartingfromdesignroomtoretailshops.Themethodsarecombinationsofworkplaceengineering,IndustrialEngineering,Visualmerchandising,RetailMarketplanning,PatternEngineeringetc.tomakethisasthebestreference.

Whatiswaste?Theimportantquestionwehavetodealiswhatiswaste?LetustrytodiscussintermsofGarmentEngineering,Therearethreetypeofwastearisinginthegarmentproduction,

1.Physicalwastage2.Technicalwastage3.Economicwastage

Physicalwastearethosewastegeneratedintheformoffabric,thread,trimsetc.thesewastearecountableandgenerallycontrolledinanygarmentindustrybecauseitisnoticeable.

Technicalwasteagegenerallycalculatedasthewasteofhumaneffort,Machinewaste,timewastedetc.whenwecalculateforagarmentindustrythetechnicalwastecomesmorethan60%ofthetotalwaste,andthisisgenerallynotmonitored.

Bothtechnicalandphysicalwastewillgenerateeconomicwastewhichresultinprofitoftheorganization.AnApparelEngineer’sjobistoreducethetechnicalandphysicalwaste,heshouldmoreconcentratetoreducethetechnicalwaste.

HistoryofGarmentIndustry.

Industrialrevolutionstartedinthe19thcentury,garmentindustryalsobegantoevolvebutitwasinitsimmaturityandhadnodevelopedsystemforgarmentmanufacturing.The

IndianclothingandapparelindustryhaditsoriginduringtheSecondWorldWarmainlyformassproductionofmilitaryuniforms.Technologyhasbeengraduallyupgradedfromtheancientpedalsewingmachineriestomostmodernautomaticsewingmachinesnowadays.NowIndiaisemergedasastrongdestinationofalltypesofapparelproductswithwideproductandquantityrange.

Theapparelindustrygrewfromthesetailors/businessmen,astheybuiltmanufacturingfactoriesforproduction,whichpatternengineeringaccommodated.Patternmakingwasfirsttaughtto“designers”.Pariswascentreofthedevelopmentsinstyleandcreationingarments,manyothercountriescopiedfromthem.Garmentindustryhasdevelopedmanynewandtimesavingtechniques,processesandmachineryfortheeffectiveproductiontoday.ThemostimportantistheCAD/CAMwhichenablesthedesigner,patternmaker,markerandgradertodotheirjobspreciselyandeffectively.

ApplicationofGarmentEngineeringinRMGTheconceptsofGarmentEngineeringareusedingarmentmanufacturingtofulfilthefollowingneeds.1.MonitoringProductionFloorandtohavebettercontroloverit2.Improvingprocessandmethodofworkingtoincreasefactoriesoverallperformance3.Standardizethegarmentmanufacturingprocessandrecordforfuture

4.Reducewastageinproductionandprocessingoperations,thewastetoreduceareFabric,Machinetime,Powerconsumption,Humanfatigue,Workmentimewastages,Machinewastage,spaceutilizationetc.

5.ProperLinebalancingandproductplanningactivities.6.MaximumutilizationofManandMachine.Etc.

Asgarmentengineeringisasystematicquestioningofalltheoperationsthatgotogethertomakeagarment,

Toeliminateallunnecessarywork:inthemostjobstherearetoomuchunnecessaryworks.Veryofteninsufficienttimeandeffortaregiventothetaskofeliminatingwork,ifaworkcanbedonewithoutthespecificjob,thenitisunnecessarytospendmoneyonanimprovedmethod.

Thereisnointerruption,nodelaywhilstanimprovedmethodisdeveloped,testedandinstalled,andthereisnoexpensivetrainingfortheoperatortobetaughtthenewmethod.

Bearingallthesethingsinmind,itisextremelyimportanttoexaminetheoriginalmethodofdoingtheworkalittlelongertoseewhetheranyoperationormovementscanbeeliminatedcompletelyorpartially.

CombineOperationsofElements:Whereeverpossible,thegarmentengineershouldcombineoperations,ifhe/sheisgoingtoincreaseproductivity.Inmanycasesthedivisionofthejobsintoelementsistakentoofar,andtheresultisthereistoomuchtimelostbetweenelementsduehandlingofmaterials,andwhichleadstolackofbalancebetweenoperations.

ChangetheSequenceofOperations:-inmanycases,thesequenceofoperationsinajobresultsfromtradition,orfromthemethodsoftheoriginaloperatorwhostartedthejobonanexperimentalbasis.Therehasnotbeenanyimprovementsincethattime,andmostprobablythesupervisorsoroperatorsseldomneedsachangefromthat,atthatpoint,a

detailedinvestigationbyamindfreefromprejudicecanmakesubstantialincreaseinproductivitybychangingtheorderorsequenceofoperation.

Simplifythenecessaryoperations:-insomesituationstheoperatormaybeperformingataskwhichistoocomplexandhencetheproductivitymaybelow,inthissituationitisnecessarytobreakthejobdownintosmallerdivisionswhichtheoperatorcanperformeasily,andmayneedtimetolearnthenewmethodorsometimesneedtobetrainedtoachievetheproductivityhigh.

Itisalsonecessarytoexaminetheoriginalmethodtoseewhetherajoborfixtureorsomeminoralterationstotheworkspacemaysimplyhelptheoperation.Manyjobswheretheprocessoflocationpartsbyhandisahighlyskilledoperation,canbemadetosemi-skilledorevenunskilled,whenajigisused.

Therearesomanymethodsusedtoreducethesewastages,alltoolsandmethodsclubbedtogetheristermedasGarmentEngineering,thereareIndustrialEngineering,QualityControl,PatternEngineeringetc.aretobecontrolled.TheDepartmentswheretheGarmentEngineeringMethodscanbeusedarefromthepurchasetodispatchincludingeverysessionsandactionshappeningintheGarmentIndustry.

KnowtheBasicTerms

Fiber:-Itisdefinedasoneofthedelicate,hairportionsofthetissuesofaplantoranimalorothersubstancesthatareverysmallindiameterinrelationtotheirlength.Afiberisamaterialwhichisseveralhundredtimesaslongasitsthickness.Afibermusthave1:30proportioninitsthicknesstolengthratio.

TextileFiber:-TheessentialrequirementsforTextilefiberstobespunintoyarnincludealengthofatleast5millimeters,flexibility,cohesiveness,andsufficientstrength.Otherimportantpropertiesincludeelasticity,fineness,uniformity,durability,andlusterwillmakeafiberintotextilefiber.Allfiberscannotusedtomakeatextileproductbutnowaday’smostofthefibersareusedtofortheproductionoftextileproductthemethodofspinningthemvaries.TheadvancetechnologylikeSPT(sensoryPerceptionTechnology)allowsustospinorweavetheminuteparticleslikefragrancemoleculestoafabricanddirectlytoa3Dgarmentwhichiswearable.

Yarn:Yarnisalongcontinuouslengthoftwistedorinterlockedfibers,suitableforuseintheproductionoftextiles,sewing,crocheting,knitting,weaving,embroidery,andropemaking.

Thread:-Threadisatypeofyarnintendedforsewingbyhandormachine.Sewingthreadsmaybefinishedwithwaxorotherlubricantstowithstandthestressesinvolvedinsewing.Embroiderythreadsareyarnsspecificallydesignedforhandormachineembroidery.

Fabric:-Fabricisaflexibletwodimensionalmaterialthatismadebyanetworkofnaturalorartificialfibers.Theformationoffabricmaybeinterlacing(Weaving),interloping(Knitting),orintermeshing(asinknotting,punchingetc.)

Cloth:-Clothisafabricwhichiswearablewithoutdoinganystitchesorseamsinit.Examplesarees,dhotis,shawlsetc.Ancientclothingmethodsarewearingclothindifferentways.Sometimesclothsareusedincombinationofdressorusedalone.

Apparel:-Apparelisanyclothingmaterialmadeusinganytextilefabric/material.Henceallgarmentsareapparelsbutallapparelsarenotgarments(e.g.CAPS,shoesetc.areapparels,shirts,trousers,etc.aregarments)

Garment:-Garmentisathreedimensionalformmadewithfabrics,sewingisthemajormethodusedtoconstructthegarments.Allgarmentsareapparelsbutallapparelsarenotgarments.Garmentsareusedasbasicdressingitems,therearemanydifferenttypesofgarmentsaccordingtofashionanditsdevelopment.Thefashiondesignersaredesigningthegarmentsaccordingtotheirideas,themesandusesetc.

Spinning:-Spinningisgenerallyusedtodenotetheentireprocessofmakingyarnfromthestaplefiber.Inmostcommonproductionprocessfiberispreparedbyopening,cleaning,carding,drawing,possiblycombingandroving,thenthestrandofmaterialisdrawndowntothecorrectsizeandtwistedtoproducetheyarn.

Weave:-methodorpatternproducedbyinterlacingyarnsinweavingprocess.Thebasicweavesareplain,twillandsatinweaves,mostotherweavesarethecombinationsorrearrangementsoftheseweaves.Forknittedgarmentsitiscalleddesignsorknots,therearemanystructuralaswellasfabricateddesignsinuse.

Weaving:-Weavingistheprocessofinterlacingtwoormoresetsofyarnsorsimilarmaterialssothattheycrosseachotherat(usually)rightangles.Thewarpyarnsrunslengthwiseandfillingsinrunfromsidetoside.

Warp:-alsoknownasend,isayarnthatrunslengthwiseinawovenfabric,paralleltotheselvageswhichinterlaceswiththefillingyarns(picks)indifferentpatterntoformdifferentweavesordesigns.Warpendsareheldinparallelundertensionintheloomandcertainonesareraisedordepressed,toformthe“shed”beforetheinsertionofeachpick.

Weft:-inwovenfabric,yarnthatrunfromselvagetoselvageatrightanglestowarp.ItisalsoknownasWoof,filling.Eachyarnofawarparecalledasapick,shot,orpick.Weavingmachinesareclassifiedaccordingtotheweftinsertionmethodsandfromhandloomtorapiertherateofweftinsertionvariesfrom20picksperMinutetomorethan500picksperminuteinadvancedshuttlelessloomslikeairjet,rapieretc.

Pattern:Aguideforcuttingoneormoregarments.Itincludesallthepiecesneededtomakeagarment.Apatternforagarmentstyleisgradedbytheready-to-wearmanufacturerorcommercialpatterncompanytoincludethesizerangewithinafiguretype.Patternsconformtostandardmeasurements,butinterpretationofthemeasurementsforsizingintheready-towearmarketvarywitheachmanufactureranddifferfromcommercialpatternstandards.AsetofpatternarrangedtogetherinasheetoffulllengthtoenableabulkcuttingofgarmentiscalledasaMarker.Markerefficiencyistheutilizationoffabric.

Seam:Aseriesofstitchesjoinstwoofmorepliesofmaterial.Thetermseamingorstitchingarealsousedtodenotetheprocessingofcreatingaseam.Therearemanymethodsusedcreateaseam.Thestrengthoftheseamgenerallymeasuredtocalculatethestrengthofthegarment.Generallytheseamstrengtharekeptnearertothefabricstrength.Detailswillbeexplainedlatter.Seamallowanceisthedistanceorspaceprovidedfortheseamingoperationsthiswillgenerallyaddedtotheoriginalpatternaccordingtothetypeofseamtobedone.

TecPack:ATecpackisaninformativesheet(orfile)whichencompassesallofthegarmentspecifications.Thetechpackforthegarmentsiscreatedbeforeembarkingonthegarmentmanufacturingprocess.Thefilecontainsallthedetailsofanyspecificstyleandaspectofthegarment.Thisdocumentisusuallypreparedbythedesignerandfinalizedinconsultationwiththemerchandisers,andthenforwardedtobulksamplingdepartmentortotheproductiondepartmentforthereferenceandguideforbulkmanufacturing.Onceatechpackforanystyleisdeveloped,theproductiondepartmentshouldbeabletoproceedwiththemanufacturingprocesswithouthavingtoreferbacktothedesignerforanyaspectofproduction.

Allthedetailsoftheclothingbeingproducedwillbeinthetechpack.Thetechpackswillincludefabricrequirements,trimrequirements,grading,threadcolors,etc.Themerchandisersarethusabletogoaheadandensurethattherequiredmaterialasperthetechpackismadeavailabletotheproductiondepartment,intherightquantitiesattherighttime.

Therearemanyothertermsinuse,eachonewillbeexplainedrespectively.SewingMachinesAsthisisanadvancedstudybook,Iamnotgoingtostartfromthebasics,wewillstartwiththeclassificationofsewingmachinesskippingthesewingmachineparts,etc.Therearemanymethodsofclassification,themajorareasfollow1.ClassificationbasedonBeds

a.FlatBedb.RaisedBedc.CylinderBedd.PostBede.FeedofThearm

2.Classificationbasedonstitch

a.ChainStitchb.LockStitchc.SaddleStitchetc.

3.ClassificationbasedonFeedsystems

a.DropFeedb.Needlefeedc.RollerFeedd.Unisonfeede.Differentialfeedetc.

4.ClassificationbasedonDrivea.DirectDriveb.BeltDriveThereareothermethodsusedbymanylikeclutchdriveorservodriveetc.theabovearethebasedetailsrequiredtobeknownbyagarmentengineerindetail.Letusseetheseonebyone.TypeofMachineBeds.

Sewingmachinesarethemaintoolsusedintheapparelindustry.In1834Sir.IsaacSinger

ofUKinventedthedomesticsewingmachineandin19000theSingerCompanydevelopedtheindustrialsewingmachines.Sewingmachinesaredesignedindifferentwaysdependingonthekindofmaterial,finishandseam.ThereareLightweight,MediumweightandHeavydutymachinesusedtosew,actuallyallthesethreearehavingminordifferences.ItusesdifferentPresserfoot,FeedDogorfeedingmechanismandNeedles.Itcreateddifferentbedstothesewingmachinesforamachineistogiveeaseinsewingoperation.

Bedistheportionofsewingmachinewherethesewingiseffectingorsewingprocessactuallytakesplaceonthefabric.Theareaiswithneedleplate,throatplate,andnearbyareaofthesewingmachine.Thisvaryinpositionandshapeaccordingtotherequirementofthemachinetodothesewingapplicationandspecificseamtosew.

FlatBedsewingMachines:Theflatbedisusedinthemajorityofsewing,wherealargeandopengarmentpartcaneasilybestitchedorhandledundertheneedle.Itprovidesuitablesurfaceforeachflatstitchesandalsofacilitatestheuseofmarkertocontrolthepositionofparts.E.g.areJUKIDDL8300,andmostoftheSingleNeedlelockStitchMachinesforplainseams.

RaisedBedSewingMachine:thefeedportionusuallylittleraisedformthetable.Thisistoenableeasyhandlingofmaterial.Normallyoverlockandsurgingmachineshasraisedbed.Becausethefabricorstitcharehavingelasticpropertiesduetochainstitchformation,butinleathersewing.

CylinderBedSewingMachines:thesemachinesfeatureanarrow,horizontalcolumnasopposedtoaflatbase.Thisallowsfabrictopassaroundandunderthecolumn,.Thediameterofthecylinderbedvariesfrom5cmto16cm.majorapplicationsaretoattachcuffs,doinghemsofsleevesofaknitTshirt,buttonsewing,bartackingetc.

FeedofArm:thisisalsoatypeofraisedbed,thedifferencebeingthearmportionislittlelongerandverticaltotheoperatorsothat,thepieceswillrunthroughit,theworkerstofeedthematerialalongtheaxisofahorizontalcolumn.Thedesignlimitsthediameteroftheseamsewntothediameterofthecolumn,butcancreatecontinuousseamoffabricinatubularshape.Themajorapplicationsareshirtsideseamfinishing,andtrouserinseamfinishingetc.

PostBedsewingmachine:Postbedsewingmachineshaveaverticalrectangularorroundpostrisingupfromthebedofthemachinetowheretheneedleandpresserfoormeet(wherethesewingoccurs).Postbedmachinesareusedforawidevarietyofapplicationswhereproductcannotfitontheregularflatorraisedbed.Theheightofthepostmayvaryfrom10cmto45cmaccordingtotherequirement.Themajorapplicationsbeingattachingemblemsincaps,bootmaking,leathershoeandbagsewing,glovemakingetc.

CylinderBed

FeedMechanism.PostBed

OfftheArm

Besidesthebasicmotionofneedles,loopersandbobbins,thematerialbeingsewnmustmovesothateachcycleofneedlemotioninvolvesadifferentpartofthematerial.Thismotionisknownasfeed,andsewingmachineshavealmostasmanywaysoffeedingmaterialastheydoofformingstitches.Forgeneralcategories,thereare:dropfeed,needlefeed,walkingfoot,puller,andmanual.Often,multipletypesoffeedareusedonthesamemachine.Besidesthesegeneralcategories,therearealsouncommonfeedmechanismsusedinspecificapplicationslikeedgejoiningfur,makingseamsoncaps,andblindstitching.

ElementsofFeedMechanism

Feedisonemajorcontrolofasewingmachineinact.Itistocontrolthelengthofthestitchwhilestitching.Thefeedingmechanismcontrolstheamountoffabricfedbythefeeddogduringeverysewingcycleofneedle.ThethreemainsewingmachinepartswhichtogetherconstituteadropfeedmechanismarePresserfoot,throatplateandafeeddog.Thesearealsoknownasthebasicelementsoffeedmechanism.

Thematerialforwardingofthesewingoperationisthroughfeedaction,anditisbasedonthefrictionforwardact.Thetwolayersoffabricareheldinpositionbyusingthepresserfootoverthefeeddog.Whilefeedactionofthefabric,thebottomlayerisforwardedbythefeeddogandthetoplayer,whichisinpressureheldbypresserfoot,isalsoforwarded,theperfectpressureonpresserfootisnecessarytomovethefabric.

PresserFoot.

Apresserfootisanattachmentusedwithsewingmachinestoholdfabricflatasitisfedthroughthemachineandstitched.Sewingmachineshavefeeddogsinthebedofthemachinetoprovidetractionandmovethefabricasitisfedthroughthemachine,whilethesewerprovidesextrasupportforthefabricbyguidingitwithonehand.Apresserfootkeepsthefabricflatsothatitdoesnotriseandfallwiththeneedleandpuckerasitisstitched.Whenespeciallythickworkpiecesaretobesewn,suchasquilts,aspecializedattachmentcalledawalkingfootisoftenusedratherthanapresserfoot.

Presserfeetaretypicallyspring-hingedtoprovidesomeflexibilityastheworkpiecemovesbeneathit.Themostcommonlyusedpresserfeetaretheall-purposefootandthezipperfootwhichcomestandardwithmosthouseholdmachines.However,anarrayofspecializedfeethavealsobeendesignedforanumberofuses.Amongtheseare,blindhemfoot,buttonholefoot,darningfoot,gatheringfoot,tapeattachingfoot,narrowhemfoot,opentoefoot,overedge/overcastfoot,piping/cordingfoot,quarter-inchseamfoot(6mm),quiltingquarter-inchseamfoot,rollerfoot,satinstitchordecorativestitchfoot,straightstitchfoot,pintuckfootetc.someofthemareshowninfig.

Awalkingfoot,alsoknownanevenfeedpresserfoot,hasbuilt-infeeddogsatitsbase,andishelpfulwhensewingmultiplelayersoffabric.Thefoot’sfeeddogsmovetheupper

layeroffabricatthesamerateasthemachine’sfeeddogsadvancethelowerlayer.

Awalkingfootcanbeusedforanytypeofsewingbutisespeciallyhelpfulforstraightlinemachinequilting,sewingbindingaroundtheedgesofaquilt,andwhensewinganyotherprojectthat’smadewithmultiplelayersorheavycloth,suchasragquiltprojectsanddenimquilts.

Thesemodificationstotheoriginalpresserfootaremadetoreducetheplyshiftduringthespecificoperations.Garmentengineerwillalwaysusearightpresserfootordevelopormodifythecurrentonestoimproveproductivityoftheoperation.Therearemanytypeofmodificationsmadetothepresserfoots,somecommonare,

1.HingingPresserfoot:-Themoststandardpresserfootwithspringmountedintherear,sothatitsfrontpartisup.Thiscorrespondswelltomaterialsandensuresmoothfeedingatoverlappedsessions.2.FixedPresserfoot:-exclusivelyusedfor2or3foldpipingtoassurethestabilityoffoldingisgood.3.CompensatingPresserfoot:-thisisanedgeguidepresserfootexclusivelyusedforedgeand¼”stitches.Therearethreetypesofit,left,rightandbothsidecompensating.

4.Slidingpresserfoot:-presserfootmovesforwardandbackwardbymeansofupordownofthefeeddog.Itiseffectivetoreduceunevenmaterialfeeding.Mainlyusedinleathersewingandasinbuttonsew,bartacketc.

5.Rollerpresserfoot:-Thisisusedforleathersewing.Arotatingrollersynchronizedwithbottomfeedinsteadofpressersoleislocatedonsideoftheneedleentry.Itpressesandfeedsmaterialtobesewn.

6.RingRollerPresserfoot:-nylonringsattachedtothebothsidesofthepresserfootwhichrotatesinsynchronizationwithbottomfeed,andfeedsthematerials.Thisisusedtoreduceplyshiftwhilesewingfinefabrics.

FeedDog

Feeddogsarethecriticalcomponentofa“dropfeed”sewingmachine.Itisusedtocontrolthemotionoffabric.Asetoffeeddogstypicallyresemblestwoorthreeshort,thinmetalbars,crosscutwithdiagonalteeth,whichmovebackandforthinslotsinasewingmachine’sneedleplate.Theirpurposeistopull(“feed”)thefabricthroughthemachine,indiscretesteps,in-betweenstitches.

Thisarrangementiscalled“dropfeed”inreferencetothewaythedogsdropbelowtheneedleplatewhenreturningforthenextstroke.AllenB.Wilsoninventeditduringthetimeperiod1850to1854,whilealsodevelopingtherotaryhook.Wilsoncalledita“four-

motionfeed”,inreferencetothefourmovementsthedogsperformduringonefullstitch:upintothefabric,backtopullthefabricalongtothenextstitch,downoutofthefabricandbelowtheneedleplate,andthenforwardtoreturntothestartingposition.

Virtuallyalldrop-feedsewingmachinescanvarytheirstitchlength;thisistypicallycontrolledbyaleverordialonthefrontofthemachine.Theyareusuallyalsocapableofpullingthefabricbackwards,toformabackstitch.

Thefeeddogcontainsawtoothwhicharelikeasw.Thedistancefromtoothtotoothiscalledastooth“pitch”,normallymeasuredinmillimeters.Thestructureofthefacesideofthefeeddogiszigzaganditcontainsteeth.Therearemainlythreetypesoffeeddogs

1.Sawtoothedfeeddog

2.UprightToothedfeeddog3.Diamondtoothedfeeddog

Forward-down-backward-up;thesefourstepsofthefeeddoghelpsthemachinetopullthefabricwhilestitching.

Thetoothofthefeeddogwhenraisesthroughtheopeninginthethroatplateandengagestheundersurfaceofthefabric.Ittakesthefabricalongtowardsthebackofthemachineandthendropsitbelowthethroatplatebeforecommencingthewholecycleagain.Theup-downdirectionalmovementoftheneedleistobesynchronizedaccordinglywiththefourstepellipticalmotionofthefeeddogtopullthefabriconlywhentheneedleisnotincontactwiththefabric.

Inasewingmachinethenumberoffeeddog,itsposition,length,shapeandnatureoftoothsurfaceetc.canbevariedatanysituationbasedontheapplicationrequirement.The

rationalebehindthisis,whenasingleroworshortlengthofthefeeddogprovidesverylesssurfacecontactandreducesfrictionbetweenthematerialandthefeeddog,itcreateaproblemoffabricslippageduringsewingeitherofthesidesinsteadofpassinginastraightline.

Inanoverlockmachine,thefeeddogismainlytotheleftoftheneedledroppointasittrimsandsewstotheright,alsothereisachainingofffingeronthethroatplateoverwhichtheloopsareformedasstitch.Theteethonthesurfaceareslightlyslantedtowardsthedirectionoffeeding.

Forsewinglighttomediumweightfabricstheteethpitchof1.3mmto1.6mmisnormal.Onaverylightfabricsaggingcanoccurbetweentheteethandpuckercanappearaftersewingasaresult.Fineteethedfeeddogswithapitchof1.0mmto1.25mmcanbeusedtopreventthis.Onheavyweightfabrics,acertainamountofsaggingisrequiredforsatisfactoryfeedinginordertokeepboththepliestogether.Inthiscase,coarserfeeddogsof2.5mmoraboveteethpitchmaybeneeded.Basedonthefabrictypeandrequirementsrubbercoatedfeeddogswithnosharpteethcanalsobeusedforverydelicatematerialslikesoftleatherorsoftfabrics.

Feeddogsshouldnothavesharpedgesatthetop,toavoiddamagetothematerialandtoreducethreadbreakages,sotheteethareslightlygrindedatthetoptoreducethesharpedges.Ifthewidthofthetopsurfaceatthetopofthetoothis0.1mmormore,thenitneedtoreducethefeedforceorelsethereisachanceforunevenstitchonmaterialslipmayresult.

Throatplate/Needleplate

Sewingmachinethroatplateisametalplatebeneaththepresserfoot.Theplatehasholesandslots,theholesaretoallowneedletopassthroughduringitsdownwardmovementonstitchingcycleandtheslotsorgrovesallowthefeeddogtoraiseandmoveduringitscycleoperation.Theneedle/throatplateistoholdthematerialfromstuckinmachinepartsandtoeaseafreemovementthroughthestitchingcycleeffectively.Themainfunctionofathroatplateistoprovideasmooth,flatsurfaceoverwhichthefabricpassesassuccessivestitchesareformed.Thegrovesandholesaretomatchthefeeddog.

Thesewingmachinethroatplatecanlookdifferentdependingonthetypeofsewingmachinetheyaredesignedtofit.Usuallythroatplatesfornormalusearemarkedwithsmallgroves¼inchesapartonthe

FineFabric1.0to1.25mmMediumFabrics1.3to1.6mmMediumHeavy1.75to2.0mmHeavyWeight2.5mmorabove

rightsidetouseasguidelinesforsewing.

Theneedleholeforastraightsewregularmachineareroundinshapeanditshouldonlybeabout30%largerthantheneedlesize.Iftheneedleholeislargethefabricmaybepushedintotheholewhileneedlepenetratesit,thisproblemisknownas“FLAGGING”andresultsmissedstitchesandyarnbreaksoften.Fabricflaggingisamachinerelatedissue,thethroatplateaperturemayenlargeduewearandtearalso.Thiscanalsohappenwhentheneedlesizeischangedandifthethroatplateisnotchangedaccordingly.Andthroatplatesmustbechangedatthegivenintervals.

Inzigzagmachinesaverticalgroveinsteadofaholeisusedtopasstheneedle,itisbecauseofthemovementoftheneedle.Theneedleholesorgrovesareusedinstraightlinestitching,theshapeandselectionispurelybasedonthestitchformationandmodeofneedlemovement.Thethroatplateofanoverlockmachineishavingloopingfingerstohelpthesergertomakeloopsontherightend.

FeedMechanismsinSewingMachines.

Besidesthebasicmotionofneedles,loopersandbobbins,thematerialbeingsewnmustmovesothateachcycleofneedlemotioninvolvesadifferentpartofthematerial.Thismotionisknownasfeed,andsewingmachineshavealmostasmanywaysoffeedingmaterialastheydoofformingstitches.Forgeneralcategories,thereare:dropfeed,needle

feed,walkingfoot,puller,andmanual.Often,multipletypesoffeedareusedonthesamemachine.Besidesthesegeneralcategories,therearealsouncommonfeedmechanismsusedinspecificapplicationslikeedgejoiningfur,makingseam.Thedifferenttypesoffeedmechanismsusedinsewingmachinesare,

Dropfeed

Thedropfeedmechanismisusedbyalmostallhouseholdmachinesandinvolvesamechanismbelowthesewingsurfaceofthemachine.Whentheneedleiswithdrawnfromthematerialbeingsewn,asetof“feeddogs”ispushedupthroughslotsinthemachinesurface,thendraggedhorizontallypasttheneedle.Thedogsareserratedtogripthematerial,anda“presserfoot”isusedtokeepthematerialincontactwiththedogs.Attheendoftheirhorizontalmotion,thedogsareloweredagainandreturnedtotheiroriginalpositionwhiletheneedlemakesitsnextpassthroughthematerial.

Whiletheneedleisinthematerial,thereisnofeedaction.Almostallhouseholdmachinesandthemajorityofindustrialmachinesusedropfeed.ThemainproblemcausedindropfeedisPLYSHIFTING,thisisbecausewhentwopliesfabricsaresewn-lowerplymovesforwardbythehelpoffeeddogbutfoot.Sotwopliesoffabriccannotmoveforwardatthesamespeed.Asaresultlowerplyismorefedthanupperply.Thisiscalledplyshifting/differentialfeedingpucker/feedingpucker.Sometimesropingisoccurredduringmakingofhemduetoplyshifting.Toavoidsuchdefectsindropfeeditisnecessarytohavegoodpresserfoot,NeedleandFeeddogalignment.Arightselectionofalltheelementsisalsonecessary.

Differentialfeedisavariationofdropfeedwithtwoindependentsetsofdogs,onebeforeandoneaftertheneedle.Bychangingtheirrelativemotions,thesesetsofdogscanbeusedtostretchorcompressthematerialinthevicinityoftheneedle.Thisisextremelyusefulwhensewingstretchymaterial,andoverlockmachines(heavilyusedforsuchmaterials)frequentlyhavedifferentialfeed.Formoreclear,whenthespeedofthefrontfeeddogishigherthanthebackfeeddog.“Thebottomplyispulledbythebackfeeddogbutthiswillovercomebythegreaterspeedofthefrontfeeddog.Solesspossibilityofshifting”.Whenthespeedofthefrontfeeddogisless“wegetlacyeffectbecausethefeedingspeedingreaterthanthedeliveryspeed”.Stretching&gatheringoffabriccanbedonebythissystem.

Needlefeed/walkingNeedle

Aneedlefeed,usedonlyinindustrialmachines,movesthematerialwhiletheneedleisinthematerial.Infact,theneedlemaybetheprimaryfeedingforce.Someimplementationsofneedlefeedrocktheaxisofneedlemotionbackandforth,whileotherimplementationskeeptheaxisverticalwhilemovingitforwardandback.Inbothcases,thereisnofeedactionwhiletheneedleisoutofthematerial.Needlefeedisoftenusedinconjunctionwithamodifieddropfeed,andisverycommononindustrialtwoneedlemachines.Householdmachinesdonotuseneedlefeedasageneralrule.

Upperpivotneedlefeed.

Theneedlebar,whichcarriestheneedle,isheldinaframe,anditsmotionispivotedfromapointontheframefarthestfrom(orfarfrom)theneedle.

Theneedlewillenterthegoodsataleadinganglefromthecenterlineofneedletravel,andwillexitthegoodsatatrailinganglefromthecenterlineofneedletravel.Inotherwords,theneedleentersthegoodsatacertainangleandexitsatadifferentangle.Thiswouldseemtodisruptthematerialandthestitchingprocess,butinpracticeitdoesnot.

Centralpivotneedlefeed.Theneedlebar,whichcarriestheneedle,isheldinaframe,anditsmotionispivoted

fromapointnearthemiddleoftheframe.

Theneedlewillenterthegoodsatagreaterleadinganglefromthecenterlineofneedletravelthanwiththeupperpivotsystemdescribedabove,andwillexitthegoodsatanequallygreattrailinganglefromthecenterlineofneedletravelthatitenteredwith.In

otherwords,theneedleentersthegoodsatacertainangleandexitsatadifferentangle.Thiswouldseemtodisruptthematerialandthestitchingprocess,butinpracticeitdoesnot,exceptwiththickerorheaviergoods.

Thereislessmomentumoftheneedlebarframeinmotionthanwiththeupperpivotsystem,andhigherstitchingspeedscanbereached.Paralleldriveneedlefeed.Theneedlebar,whichcarriestheneedle,isheldinaframe,anditsmotionisalways

parallelinrelationtoitspriorandsuccessivemovements.Itremainsperpendiculartothematerialatall

times.Forexample,iftheneedleentersthegoodsat90degreestothematerials’surface,theneedlewillremainat90degreesthroughitstravel,andwillexitatthesame90degreeangle. Itisthetypeofneedlefeedsuitableforstitchingtheheaviestandthickestofmaterials.Themechanisminvolvedinaparalleldrivemakesforamoreexpensiveunitandwill

generallyhaveaslowerstitchingspeed.

TopFeed

Topfeedischaracterizedbyamechanicalfoot,rollersattachedtofoot,feetwithteethorfrictionsurfaceorrollersthattransportorassistinthetransportofmaterialisnormallyoftenafootworkinginunisonwithadropfeed.Topfeedhasadirectionalmovementinwhichmaterialisfed.Thefootorrollersmaypushdownwardintothematerialtocapturethematerialbetweentheotherfeedcomponentssuchasbed,feeddogetc.

Thegeneralarrangementoftopfeedsystemisthatthepresserfootintwosessions,oneholdingthefabricinpositionwhiletheotherhavingteethonlowersidewhichmovesthefabric,thismotionislikewalkinginsuchawaythatthetopplyistakenalongpositivelywhiletheneedleisoutofthematerial.Therearedifferenttypesoftopfeed

VibratingPresserfootisafootwithteethorfrictionsurfacethattransportsorassists.Ithasavibratingmotionforwardwiththefeedingprocessandbackwardswiththereturnstroke.Thiswillbepairedwiththepresserfootormaybetheonlytopfeed.avibratingpresserfootisusuallyincorporatedwithaliftingmotiononthebackwardstroke.Thisallowsthefoottoclearthematerialandtodroprelativelystraightdownontoanyraisedorunevenportionofthematerialwithoutinterference.

AlternatingPresserfootisapairoffeetthatalternatelypressesagainstthematerialwhileoneofitispressingagainstorfeedingthematerialandotherfootisraisedtoclearoffthematerial.Thepositionthenalters.Onefootistypicallyavibratingpresserfootbutbothfunctionswillalterintermittentlyorcanworkonlyraisingandloweringtoholdthematerialinposition.

Awalkingfootreplacesthestationarypresserfootwithonethatmovesalongwithwhateverotherfeedmechanismsthemachinealreadyhas.Asthewalkingfootmoves,itshiftstheworkpiecealongwithit.Itismostusefulforsewingheavymaterialswhereneedlefeedismechanicallyinadequate,forspongyorcushionedmaterialswhereliftingthefootoutofcontactwiththematerialhelpsinthefeedingaction,andforsewingmanylayerstogetherwhereadropfeedwillcausethelowerlayerstoshiftoutofpositionwiththeupperlayers.

JumpFootsarevibratingpresserfeetwherebackwardandforwardmotionsarenotdriven,butspringloaded.Thisisusuallyincorporatedwithaliftingmotiononthereturnstroke.Thisisthemostconventionalformoftopfeed.

Clampfeedshavingclampsfromabovethematerialandpressingdownward,effectivelyholdingthematerialbetweenitselfandthemachinebedoraclamporclampsaboveandbelowthematerialholdingthematerialfirmly.Theclaporclampsetsaredrivenbylinkageswhichmovesduringsewing.Thisisusedinunisonwithotherfeedsystemstogeteffectseamsproduced.

CombinationFeedForspecialrequirementsofqualityofsewingwemayusecombinationfeeds,generallyitisthecombinationofdifferentfeedmechanismstogether.

TopandBottomFeedcombination:-acombinationofanytopfeedandafeeddogordropfeedisusedasonemethod.AlsoCompoundFeedisacombinationofneedlefeedanddropfeedarethetwodifferentcombinationfeedsinact.

UnisonFeedisatermusedintwodifferentways,oneapplicationofthistermisitsapplicationanytwoormorefeedusedtogetherandthesecondistodescribetheuncommonfeedsystemofavibratingpresserfootoralternatingfootalongwithneedlefeedandadropfeedorfeeddogworkingincombinationbutoperatingfromanonepieceframe.Theframeextendsfromthepresserfootorneedlefeedmechanismthroughthemachinecastingtothedropfeedorfeeddog.

Pullerfeed

Somefactorymachinesandafewhouseholdmachinesaresetupwithanauxiliarypullerfeed,whichgripsthematerialbeingsewn(usuallyfrombehindtheneedles)andpullsit

withaforceandreliabilityusuallynotpossiblewithothertypesoffeed.Pullerfeedsareseldombuiltdirectlyintothebasicsewingmachine.Theiractionmustbesynchronizedwiththeneedleandfeedactionbuiltintothemachinetoavoiddamagingthemachine.Pullersarealsolimitedtostraightseams,orverynearlyso.Despitetheiradditionalcostandlimitations,pullingfeedsareveryusefulwhenmakinglargeheavyitemsliketentsandvehiclecovers.

Arotarywheelwillhaveamovementinthedirectionoffeed.Itincorporatesafrictionsurfaceorclampingsurfacethatfeedsorassistsinfeedingthegoods.Ithaseitheranintermittentmotionoracontinuousmotion.Continuousmotionwheelfeedmustworkinunisonwithaneedlefeed.

ThereareUpperandlowerwheelfeed.Wheelfeedsystemwhereanupperandlowerwheelarebothdriven.Thematerialisfedbetweenthewheels.Thereispositivefeedingpressureboththetopandbottomofthematerialatthesametime.

Manualfeed

Amanualfeedisusedprimarilyinfreehandembroidery,quilting,andshoerepair.Withmanualfeed,thestitchlengthanddirectioniscontrolledentirelybythemotionofthematerialbeingsewn.Frequentlysomeformofhooporstabilizingmaterialisusedwithfabrictokeepthematerialunderpropertensionandaidinmovingitaround.Mosthouseholdmachinescanbesetformanualfeedbydisengagingthedropfeeddogs.Mostindustrialmachinescannotbeusedformanualfeedwithoutactuallyremovingthefeeddogs.

MaterialFlow,ProcessFlow,PlantLayout,ProcessCharts,Spacerequirements,FactoryLayout

2FacilityLayoutandMaterialHandling

Factoryisaplacewherealltheindustrialactivitiesarehoused.Aftertheselectionofthefactorysite,itisnecessarytoconstructabuilding.Therearetwotypesofbuildingaccordingtolocation.Inmanycasesthegovt.orlocalauthoritymayprovideuswithastandardindustrybuildingtooperatewith,inthatcaseswehavetoallocatevariousdepartmentsofthecompanyintheroof,sothatallwillgivemaximumfunctionwithminimumresponsetime.Whileinthesecondcasewecandesignthefactorybuildingbyallocatingthedepartmentsasweneed.Itshouldbenotedthat,thoughtheproblemoffactoryandplantlayoutsarisesonlyafterthebuildingfacilitieshavebeenmadeavailable,theyareconsideredalongwiththeconstructionofthefactorybuilding.Certainspecificrequirementsoftheadministrativedepartmentsandthecharacteristicsoftheproductionprocessandplantserviceshaveadirectbearingontheconstructionofthefactorybuilding.Thusforaneffectiveproductivitybothfactorybuildingandfactorylayoutareconsideredsimultaneously.Thearchitecturaldesignandtheexteriorviewofthefactoryisconsideredwiththetechnicalrequirementofvariousdepartments.Theemphasisisgiventothetechnicalaspectsratherthantheaestheticconsiderations.Thedifferencebetweenfactorylayoutandplantlayoutshouldbenotedsensibly.Thefactorylayoutisabroadconsiderationanditdecidesaboutthehousingofalltheactivitiesinsidethefactory,generallytheactivitiescanbedividedintotwogroups;

1)OfficeArea:-inwhichtheadministrativedepartmentsshouldbeaccommodated.2)PlantArea:-wheretheProductiondepartmentandServicedepartmentsshouldbeaccommodated.WecandifferentiateServicedepartmenttotwo,Technicalservice:-Likereceivingdepartments,store-room,stockroom,toolrooms,inspectiondepartment,powerhouse,materialhandlingdepartment,packingandshippingetc.PersonalService:-likeparkingarea,securityrooms,canteenrooms,recreationrooms,toiletsetc.Inrelationtofactorylayout,plantlayoutisanarrowconsiderationandconcentratesonthearrangementofproductionandservicedepartmentsalongwiththelocationandsequenceofmachinesandequipment.

Perfectplantlayout.Aplantlayoutistheoverallarrangementoftheproductionprocess,likestoreroom,cuttingroom,productionroom,finishing,packing,shipment,employeeserviceandallotherfixturesrequiredforhelpingtheproductioninthefactory.Itshouldbesothatbycompilingtheproductionandservicesessionsandtoprovideforthemosteffectiveutilizationofmen,materialandmachinesorganizingtheprocess.Thisisthemasterdesignforcoordinatingalloperationsperformedinsidethefactory.Agoodlayoutisonewhichallowsmaterialsrapidlyanddirectlyforprocessing.Thisreducestransport,handling,clericalandothercostsreducedperunit.Itshouldhaveareducedspacerequirementsandwillreduceidlemanandmachinetime.Theobjectivesofaperfectplantlayoutwillbestrivingtoachievethefollowing,

1)Minimizedmaterialhandling2)Eliminationofbottle-necksthroughplantcapacitybalancing

3)Highmaterialturnoverthroughshorteroperatingcycle.4)EffectiveutilizationofinstalledcapacitysothatROI(returnofinvestmentwillbemaximum)5)Effectiveutilizationofspaceusage(reducedcubicspaceoffactoryarea)6)Reducedidletimeandhenceeffectivemanpowerutilization.7)Elimination,improvementorconfinementofobjectionable(vibratingornoisyetc.)operations8)Eliminationorreductionofphysicaleffortsrequiredofoperativeworkers.9)Canavoidindustrialaccidents10)Betterworkingconditionsforemployeeslikelightening,ventilation,noisereductionandreducedornovibrationsetc.andhencereducingsomeamountoffatigue(tiredness)11)BettercustomerservicethroughgoodqualityincheappricedandcanhavegooddeliverypromisesFactorsaffectingPlantLayoutchoiceTheselectionofplantlayoutismadeaccordingto,

1)TypeofProduction:-thelayoutswillbedifferentforagarmentunittoanaccessoryunit.2)ProductionSystem:-theplantlayoutforamakethroughwillbedifferentformunitproduction.3)Scaleofproduction:-differsinalarge-scaletosmallscaleorganizations,themaindifferencewillbeinthematerialhandlingdepartmentsonthese.4)Typeofmachines:theuseofsinglepurposeandmultipurposemachinessubstantiallyaffectstheplantlayout.Alsotheremaybesomemachinesneedsspecialattentionssuchasanembroiderymachineneedseparateroomsifusedinmultipleheadswhileasingleheadusescanbeusedinthesameroomprovidedithasrequiredconditionsmet.5)Typeofbuildingandfacilities:thelayoutsweprepareforasinglestoryandmulti-storywillbedifferent,sameasifwehaveapre-designedstandardindustrybuildingwilldifferfromaspecificdesignedindustrybuilding.6)Totalavailablefloorarea:theallocationofspace,machines,storesetc.willbemadeonthebasisoftheavailablefloorareaonly.Sometimesweneedtoprovideoverheadspacesorplatformstomakeuseoftocreateormeetmorespacerequirements.7)Needoffutureexpansion:ifthecompanyplansfuturegrowthandtherearepossibilitythenwewilldesignthefloorconsideringfutureexpansionrequirements.8)Materialhandlingdepartment:Theplantlayoutiscloselyrelatedtothematerialhandlingserviceandithasacriticaleffectonthearrangementofproductionprocess.Itisbecausetheproductionindustryismainlyrelatedtothematerialhandling,highhandlingtimemeansreducedcapacity.

Materialflowsystem.

Man,machinesandmaterialsarethethreebasicinputsinthemanufacturingprocess.Generallymenandmachinestendtoremainstaticwhilethematerialsmovefromoneworkstationtoanotherforthepurposeofprocessing.Therawmaterialspassthroughvariouspathstilltheyareconvertedtofinishedproduct.Thepatternofmovementofmaterialsinsidetheplantareaisarrangedunderdifferenttypeoffloorsystems.Thepatternofmaterialflowisimportantbecausetominimizetheflowofmaterialsisnecessary.Thepatternofflowofthematerialsislargelydecidedbythetypeoflayout.

Intheproductlayoutthematerialflowissmoothandshort,whileintheprocesslayoutitislongandinvolvesmanycomplexities.Theflowpatterniscloselyrelatedtothetypeofthematerialhandling,typeofmaterialsandthecostofmaterialhandling.Italsoneedtoconsidertherequirementoftemporarystoring,spotsofbottlenecksorrushing.Theoperatingcycleperiodhasacloserelationwiththeflowpatternofmaterials.Theflowpatternofmaterialsistoreducethebottlenecksrushing,back-trackingandensuregoodsupervisionandqualitycontrol.Italsohelpsinminimizingthematerialhandlingcost,effectiveutilizationofplantcapacity,reductionintheoperationcycleandresultsincreaseinreturnsoninvestment.ThematerialflowsystemsarebroadlydividedintotwoonthebasisofthenatureoftheavailabilityoffloorspaceasHorizontalsystemandverticalsystem.

HorizontalSystemofmateialflow:-Thissystemsaredevisedmajorlyinasinglestorybuildingwhenaflatfloorareaisused.Thestartingpointisthe“receiving”ofrawmaterialsandtheterminalpointisthe“Shipment”forfinishedgoods.In-betweenthesepoints,thematerialsmovefromoneworkstationtoanotherforthepurposeofprocessing.Thehorizontalflowsystemisgenerallydenotedusingthealphabets.ThereareI,L,U,S,O,IU,ISandIOsystemsused.“I”TypeFlow

“L”TypeFlow

ShortestRouteMusthaveroadsonbothsidesPlantareahaslonglengthbutshortwidthDifficultyinreturningemptycontainersAbsenceofrushingofoutsidetransportationUnsuitableforlongerproductionlines.

ShortestRouteMusthaveroadsonbothsidesPlantareahaslonglengthbutshortwidthDifficultyinreturningemptycontainers

AbsenceofrushingofoutsidetransportationUnsuitableforlongerproductionlines.

“U”TypeFlow

“S”TypeFlow

OnesideroadisrequiredLessdifficultyinreturningemptycontainersPossibilityofrushingoutsidetransportationSuitableforlongerproductionlinesRequiresquarelikefloorspace

RequireroadsonbothsidesAbsenceofrushingofoutsidetransportationRequiresquarelikefloorspaceDifficultyinreturningemptycontainersSuitableforlongerproductionline.“O”Typeflow

Combinationof“I”and“U”Flow

Combinationof“I”and“O”OnesideroadfacilityisrequiredHeavyrushofoutsidetransportationEaseofreturningemptycontainersRequiresquarefloorspaceSuitableforlongerproductionline.

Combinationof“I”and“S”Flow

Allcombinationflowstructurehavethecombinedcharacteristicpropertiesandrequirementsofboththemethods.Selectionoftheseispurelybasedonthetotalfloorarea,andnumberofoperationstobecarriedoutandmachineoroperatorrequirementtoreducebottlenecks.

VerticalSystemofmaterialflow:-thismethodarisesincaseofmulti-storybuildings.Multistorybuildingsareusedwherelimitedlandareaisavailableandprocessingisdoneonlightmaterialswiththehelpoflightmachines.Theadvantageofgravityflowcanbetapped,however,itfirstrequiresavailabilityofmaterialsatthetopfloor.Certainimportantverticalflowsystemdiagramsareunder,

TypeofPlantLayouts

Plantlayoutisthemosteffectivephysicalarrangement,eitherexistingorinplansofindustrialfacilitiesi.e.arrangementofmachines,processingequipmentandservicedepartmentstoachievegreatestcoordinationandefficiencyof4M’s(Men,Materials,MachinesandMethods)inaplant.Layoutproblemsarefundamentaltoeverytypeoforganization/enterpriseandareexperiencedinallkindsofconcerns/undertakings.Theadequacyoflayoutaffectstheefficiencyofsubsequentoperations.Itisanimportantpre-requisiteforefficientoperationsandalsohasagreatdealincommonwithmanyproblems.Oncethesiteoftheplanthasbeendecided,thenextimportantproblembeforethemanagementoftheenterpriseistoplansuitablelayoutfortheplant.AccordingtoJamesLundy,“Layoutidenticallyinvolvestheallocationofspaceandthearrangementofequipmentinsuchamannerthatoveralloperatingcostsareminimized”.InthewordsofMallickandGandreau,“Plantlayoutisafloorplanfordeterminingandarrangingthedesignedmachineryandequipmentofaplant,whetherestablishedor

contemplated,inthebestplace,topermitthequickestflowofmaterial,atthelowestcostandwiththeminimumhandlinginprocessingtheproduct,fromthereceiptofrawmaterialtotheshipmentoffinishedproduct”.AccordingtoApple,“Plantlayoutisplanningthepatheachcomponent/partoftheproductistofollowthroughtheplant,coordinatingthevariouspartssothatthemanufacturingprocessesmaybecarriedoutinthemosteconomicalmanner,thenpreparingdrawingorotherrepresentationofthearrangementandfinallyseeingthattheplanisproperlyputintoeffect.”(PlantLayoutandMaterialbyApple).InthewordsofSansonnetiandMalilick(FactorymanagementVol.103)“Itisplanningtherightequipment,coupledwithrightplace,topermittheprocessingofaproductunitinthemosteffectivemanner,throughtheshortestpossibledistanceandintheshortestpossibletime.”Thelastdefinitionseemstobemostappropriate.Manysituationsgiverisetotheproblemofplantlayout.Twoplantshavingsimilaroperationsmaynothaveidenticallayout.Thismaybeduetosizeoftheplant,natureoftheprocessandmanagement’scaliber.Thenecessityofplantlayoutmaybefeelandtheproblemmayarisewhen.i.Therearedesignchangesintheproduct.ii.Thereisanexpansionoftheenterprise.

iii.Thereisproposedvariationinthesizeofthedepartments.iv.Somenewproductistobeaddedtotheexistingline.v.Somenewdepartmentistobeaddedtoenterpriseandthereisreallocationoftheexistingdepartment.vi.Anewplantistobesetup.

Thepossibilityofattainingthebestpossiblelayoutisdirectlyproportionaltofollowingfactors:TheWeight,VolumeorMobilityoftheProduct:-Ifthefinalproductisquiteheavyordifficulttohandleinvolvingcostlymaterialhandlingequipmentoralargeamountoflabour,importantconsiderationwillbetoamounttheproductminimumpossiblee.g.boiler,turbines,locomotiveindustriesandhipbuildingcompaniesetc.ComplexityoftheFinalProduct:Iftheproductismadeupofaverylargenumberofcomponentsandpartsi.e.largenumberofpeoplemaybeemployedforhandlingthemovementofthesepartsfromshoptoshoporfrommachinetomachineoroneassemblypointtoanothere.g.automobileindustry.TheLengthoftheProcessinrelationtoHandlingTime:-Ifthematerialhandlingtimerepresentsanappreciableproportionofthetotaltimeofmanufacturing,anyreductioninhandlingtimeoftheproductmayresultingreatproductivityimprovementoftheindustrialunite.g.SteamTurbineIndustry.TheExtenttowhichtheProcessTendstowardsMassProduction:Withtheuseofautomaticmachinesinindustriesforadoptingmassproductionsystemofmanufacturingthevolumeofproductionwillincrease.Inviewofhighproductionoutput,largerpercentageofmanuallabourwillbeengagedintransportingtheoutputunlessthelayoutisgood.Thefollowingarethepopulartypeofplantlayouts,

1.Processlayout2.Productlayout3.CombinedLayout4.StaticproductlayoutorProjectlayout5.Cellularlayout

6.JobShopLayout

Forthebetterproductivitybylimitedresource,beforedoingtheconstructionofthebuildingitisrequiredtodothedetailedstudyandpreparationoftheplantlayoutsothatminimummachinesonlyneedtopurchase,withminimummanpower,spacerequirementsmaximumoutputcanbegainedfromarightandproperpreparedlayout.

ProcessLayout

Allmachinesperformingsimilartypeofoperationsaregroupedatonelocationintheprocesslayout.Itisalsoknownas“thefunctionallayout”e.g.allsewingmachines,pressingmachinesetc.inthegarmentindustrywillbeclusteredintheirlikegroups.Thesequentialarrangementofthemachinegroupisgenerally,butnotnecessarily,madeonthebasisoflabouroperation.Inthislayouttheprocessratherthanaproducthasthedominatingrole.Theproductisgivensecondaryconsiderationandismovedforthepurposeofoperationstotheprocesssectionwithlikemachinesstationedataparticularpoint.Thistypeofprocessismoresuitabletojobordertypeofproduction.Insuchproductiontheoperationsdifferfromproducttoproduct.Soitisdesirabletoarrangethemachinesonthebasisofprocessratherthanonproducts.Forexampleasmallscalegarmentindustrywithabout20to40machines,whoareworkingforthepivotbrandsandlocalorders,mayhavetogowithdifferentstylechangesfrequentlyandtheremaybeproductchangefromshirttotrouserorfromkidstoadultsetc.InsuchsituationthemachineshastoarrangedinaccordingtotheprocesssuchasSingleNeedle,doubleneedle,buttonhole,bartack,overlocketc.aretreatedasdifferentprocessandwillbeallocatedseparately.Itisbecausetoutilizethemforproducingdifferentstylesinsametime,sothatproductAandproductBcanbeloadedintothesameindustrysimultaneouslybycalculatingtheproductionprocess.Thiswillreduceidlemachinesandoperators.Atypicalexampleisshownbelow,

Themainadvantagesare,

Iteliminatetheduplicationofmachinestoitsmaximumandenablestheoptimumuseofinstalledcapacity.Itfacilitatestheflexibilityinproduction.Theproductioncapacityisnotarrangedinrigidsequenceandfixedratedcapacitywithlinebalancing.Thebreakdownofonemachinedoesnotinterrupttheentireproductionflow.Specializationinsupervisionbecomespossibleasthedepartmentsareworkingonseparateoperations.Individualincentiveschemescanbedeveloped.

Alsothefollowingarethemaindisadvantagesofprocesslayout.

Duetolackofstraightlinesequenceofproduction,itisimpossibletomaintainthelinebalancinginproduction.Hencetheproblemsofbottleneck,waitingandidlecapacityarise.Thecostofmaterialhandlingincreasesduetolongroutingandbacktrackingbetweentheprocesses.Theprocessingtimeisprolongedwhichreducestheinventoryturnoverandincreasetheinvestmentsininventories.Theinspectioncostincreases.Duetofrequentchangesinthemachineset-up,inspectionisrequiredateachstageofprocess.Thecostofsupervisionincreasesduetospecialistsupervisorsandmorenumberofsupervisorsarerequiredateachprocessunit.Productionplanningandcontrolbecomesdifficultduetocomplexitiesarisinginrouting,scheduling,dispatchingandfollow-up.Itisnotpossibletoimplementthegroupincentiveschemesonthebasisofquantityof

productsmanufactured.Morespaceisrequiredforinternalstoring,reservoirofmaterialandprovisionfortheexpansionofparticularprocesssectiononrequirement.

ProductLayoutInproductlayout,themachinesarearrangedinthesequenceasrequiredbytheparticularproduct.Allmachinesasrequiredtobalancetheparticularproductlinearearrangedinasequentiallinebutitmaynotnecessarilyinthestraightline.Inthistypeoflayouttheproductisgiventheprimaryimportanceandtheprocessmachinemustremainpresentatapointwheretheproductneedsitsservice,asasecondaryimportance.Productlineismoresuitableforcontinuousflowproductionwithfewitemsofproduction.Itdoesnotrequirefrequentchangesinmachineset-up.Thetypicalarrangementofproductlayoutisasinthefigure,

Themajoradvantagesofaproductlineare,Reducedmaterialhandlingcostduetostraightlineproductionflow.

Mechanismofmaterialhandlingispossibleduetohandlingbetweenfixedpoints.Betterlinebalancingispossibletoreducebottlenecksandidlecapacity.Shorteroperatingcycleduetoshorterandspeediermovementofmaterials.Maximumutilizationofmachineandlabourcapacitythroughdevelopingproperbalancebetweenthem.Effectivecontroloverproductionwithreducedsupervisionbysupervisors.Reducedinspectionpointswillgiveeffectivequalitycontrol.Moreeffectiveproductionplanningandcontroldueeasierrouting,scheduling,dispatchingandfollow-ups.Maximumuseofspaceduetostraightproductionflowandreducedneedofinterstoring.

Thedisadvantagesofproductlayoutare,

Duplicationofmachinesandequipmentnecessitatesintheincreasedinvestment.Andmayhaveidlecapacityifrunningwithalowquantityorder.Thesystemishighlyinflexibleastheproductionflowisregulatedstraightlinethroughsequenceandfixedratedcapacity.Thebreakdownofanyonemachineinalineinterruptstheentireproductionflow.Specializationsupervisionisnotpossible.Astheentireproductionistheresultofjointeffortsofalloperatorsintheline,itisdifficulttoimplementindividualincentiveschemes.

MixedorCombinedLayoutPureproductofprocesslayoutisnotfoundinpracticegenerally.Onlyapropercompromisereapingthebenefitsofboththelayoutispossibletosomeextent.Combinedlayoutsaredevelopedas,Productlayoutforthemainproductwithaprocesslayoutforjointorby-producttappingtheidlecapacityofproductlayoutalongwithmarginalinvestmentrequiredinprocesslayout.Todiversifytheproductionwithviewtotaptheidlecapacityoftheproductlayout.Productwithcompletenegativecorrelationwiththeproductlinecanmaketheuseofmaximumidlecapacityoftheproductlayout.Intheproductlayout,someprocessmaybesegregatedfromtheproduct-line,whichmayrequirespecialtreatmentsandrepetitiveperformance.

StaticProductlayoutorProjectLayout

Themanufacturingoperationrequiremovementofmen,machinesandmaterials.Generallyfewinputstendtobestaticwhiletheothersaremoving.Intheproductandprocesslayoutsgenerallythemachineshavefixedinstallationsandoperatorsarehavingstaticworkstations.Itisonlythematerialsmovefromoperationtooperationforthepurposeofprocessing.Butwheretheproductislargeinsizeandheavyinweight,suchasshipsetc.ittendstobestatic.Insuchproductionsystemstheproductremainstaticandthemachineandmenmoveperformingtheoperationsontheproduct.

CellularorGroupLayout

Tobringelementofflexibilityintomanufacturingsystemsandtheupdatingintechnologyformaterialhandlingetc.andbatchsizevariationsanddifferingoperationsdueshortrunstyles,theFlexibleManufacturingSystem(FMS)aredesigned.Itwasfirstinstalledin1968atEngland.Thiswasmoresuitableforelectronicassembly.FMSisamixtureoftraditionalwithmoderncomputerizedautomationswhichessentiallyconsistsofasetofmachinesperformingoperationslinkedupwithmaterialhandlingsystems.Thegroupingintocellsenabletheperformanceofsimilartypeoffunctionsforagroupofproducts.

IngarmentindustrywhereweuseEton®systemofproductionisanexampleforcellularlayout.Itisnecessarytooptimizethehostfactorstohaveandideallayout.Themajorclustersoffactorsaffectingthelayoutare,

1.Manpowerfactors2.Machineryfactors3.Movementfactors4.Materialfactors5.Waitingfactors6.Servicefactors7.Factorybuildingfactors8.Changeinproductionrelatedfactorsetc.Foreachfactoryitisfirstnecessarytolistoutthesekeyfactorsandpreparethelayoutsoastosatisfyallofthesemakesaperfectlayout.

LayoutDesignProcedureThelayoutdesignmovesfromidealtowhatispracticalunderthelimitationsgiven.Theplanasawholeismadefirst,anddetailsareaddedafterwards.Therequirementofmaterialiscentraltoallayoutplanning.Theprocessandmachinerymayneedmodificationsinthelightofdifferentfactorsaffectingthelayoutplan.Thefollowingarethestepsfollowedingeneralforalayoutpreparation

1.Determinetheobjectivesandlimitations2.Collecttheinputdataandstudytheactivitiesinvolved.Theinputdatamaybeaboutsalesforecasts,productionforecasts,workstudy,existinglayouts,chartsetc.3.Determinetheflowofmaterialsandactivityrelationshipsandpreparearelationshipdiagram.Itshouldbesubjectivetospaceavailableandspacerequired.Probablytermedasaspacerelationshipdiagram.4.Thepreparedspacerelationshipdiagramismodifiedinthelightofvariousconsiderationsandpracticallimitations.5.Prepareasmanydifferentlayoutsforthespecificlocationandcarefullystudyeachoneofthemandthenevaluatecriticallytofinalize.

Inordertodesignagoodlayout,werequirequantitativeandqualitativedataaboutvariousfactorsaffectingtheplanlikeproductattributes,outputvolume,componentpartsetc.arerequired.Datarequirediscollectedonacontinuousbasisthroughtechniqueslikeindustrialengineeringmethods,qualitycontrol,marketresearches,timeandmotionstudyetc.andrecordthevariousmaterialsprocess,flowsequences,spacerequirementandavailabilityetc.

ProcessCharts.

Themostcommonlyusedprocesschartsare,OperationProcessChartandFlowProcessChart.TheuseoffollowingsymbolsarerecommendedbytheAmericanSocietyofMechanicalEngineers(ASME),tosimplifytheconstructionandinterpretationofprocesscharts.

Thesesymbolsareusedtorepresentstepsintheprocedureormanufacturingprocessintheprocesscharts.Whennecessarytheoperationactivitycanbesubjectedtoamoredetailedanalysis.ThedistinctionisthenmadebetweenMakeReadyandPutAwayOperations.Thesedealwiththepreparationofmaterial,plantorequipmenttoenablethe“Do”Operationsor“Inspection”tobeperformedandwiththeplacingasideorclearingupafterthe“do”operationsor“inspection”.

“DoOperations”aretheactualperformanceoftheworkonthematerialorworkwithplantandequipment.The“do”operationsymbolscanbeshadedtofacilitatesubsequentexaminationinorderoftheimportancetotheoverallprocess.

Theprocesschartisgenerallyusedtorecordtheactivitiesthatoccurduringamanufacturingorservicingjob,thereareseveraltypesofprocesschartsinuse,andtheyaredividedmainlyastwo.1)Thosewhichareusedtorecordprocesssequence(i.e.seriesofeventsinorderinwhichtheyoccur)butdonotdepicttheeventstotimescale,theyare

-OperationProcesscharts(OutlineProcessChart)-FlowProcesscharts(Man/Material/Machine)-OperatorCharts(Twohandedprocesscharts)

2)secondonearethosewhichrecordeventsinthesequenceinwhichtheyoccuronatimescalesothattheinteractionofrelatedeventscanbemoreeasilystudied,thereare-Multipleactivitycharts-SIMOCharts

Specifythefollowingasamustforfuturereferences,a)TypeofChart

b)Jobconcernedandwhetheritisthepresentorproposedmethodc)Dateofsurveyandnameofobserverd)Wherethechartendsandwhereitstartede)Ifpresentmethodrecordtheactualoutputandefficiency

Includethefollowing,f)Adequateandaccuratedescriptionofallactivitiesontherighthandsideofthesymbolconcernedg)Numbereachactivityforidentificationpurposebyplacingthenumeralwithinthesymbol.h)Eachclassofsymbolistobenumberedinitsownsequence.

i)Numberingbeginsonthemainlineofactivitieswhichisalwaysplacedontherighthandsideorcenterofthechart.

j)Thenumberingsequencecontinuesuntilthereisajunctionwithasubsidiaryline,whenitjumpstothetopofthissubsidiaryandproceedsdownwardfromthere.Whencombinedsymbolsareused,thefirstnumberappliestotheoutersymbol.

k)Date,concerningtime,distance,weightorquantityaremaybeshownonthelefthandsideofthesymbolitrefersto.l)Asummaryofactivitiesisshownatthebottomlefthandsideofthechartm)Usethesamescaleofbreakdownintheanalysisofactivitiessothatthecomparisonofpresentandproposedmethodswillnotbedistortedbyappearance.n)Neatnessandclarityinthelayoutofthecharthelpstosimplifytheprocessofcriticalexamination.

OperationProcessChart:-Anoperationprocesschartprovidesthechronologicalsequenceofalloperationsandinspectionsthatoccurinamanufacturingorbusinessprocess.Italsoshowsmaterialsusedandthetimetakenbyoperatorfordifferentelementsofwork.Generallyaprocesschartismadeforfullassembly,thatis,itshowsalltheoperationsandinspectionsthatoccurfromthearrivalofrawmaterialtothepackagingofthefinishedproduct.

OperationProcessChart:FinishingofShirtMethod:presentLocation:AQBCharted:JKBeginning:ThreadCutting

Date:1-1-2016

Ending:ReadyShipInspection4Operation6

FlowProcessChart:-Aflowprocesschartisusedforrecordinggreaterdetailthanispossibleinanoperationprocesschart.Itismadeforeachcomponentofanassemblyratherthanforthewholeassembly.

Aflowprocesschartshowsacompleteprocessintermsofalltheelementsofwork.Therearetwomaintypesofflowcharts:productormaterialtype,andtheoperatortype.Theproducttyperecordsthedetailsoftheeventsthatoccurtoaproductormaterial,whilethe

operatorflowchartdetailshowapersonperformsanoperationalsequence.

Animportantandvaluablefeatureofthischartisitsrecordingofnon-productivehiddencosts,suchasdelays,temporarystorages,unnecessaryinspections,andunnecessarylongdistancestraveled.Whenthetimespentonthesenonproductiveactivitiesishighlighted,analystcantakestepstominimizeitandthusreducecosts.

a)ManTypeb)MaterialTypec)EquipmentType:-HowtheEquipmentisUsed

TheexampleshownbelowisaprocesschartpreparedMaterialType,heretheoperations,movement’setc.ofthematerialwillbemeasuredandrecorded,anditistonotethatthischartwillgiveacompleteideaofmaterialmovement,itstimeofmovement,anddelayetc.:-RecodeswhattheworkerDoes:-WhatHappenstotheMaterial

ThesamemethodisusedtorecordMantypeandequipmenttypebasedontherequirement,butwhiledoingarunninglinemodificationforproductionimprovementitisrequiredtoprepareallthethreemodesforthebetterresult.

OperatorProcessChart:-ItisalsocalledLeftHand–RightHandchartandshowstheactivitiesofhandsoftheoperatorwhileperformingatask.Itusesfourelementsofhandwork:Operation,Delay(Wait),MoveandHold.Itsmainadvantageliesinhighlightingun-productiveelementssuchasunnecessarydelayandholdsothatanalystcantakemeasurestoeliminateorshortenthem.

Inthetwohandedprocesschartthesymbolsareusedinaslightlydifferentway,because

ofthemotionvariationandeasymarking,isusedtorepresentHOLDandDisusedtoshowthattheparticularhandisidleatthattime.Constructingthechartusuallystartsbyrecordingactivitiesofthehandthatdoesthemostwork,thenputtingthesymbolsfortheotherhandintheirrightplaces.Mostlythemovementsbeingrecordedaresmallandfast,sotostartatthetop,withtheearliestactivityandworkdownwardsispreferablemethodofrecording.Alsoavideocanbeusedformoreaccurateplotofthechart,sothatitcanbeplayedinaslowerspeedtoidentifytheexactmovements.

thistwohandedflowchartispreparedwithoutsymbols,andiscommonlyusedforthefirstreferenceofcomplexoperations,andtoplottheoperations,thenanotheronewillbepreparedasbelow,ormaythesamecanbeusedwithsymbolsforfurtherreferences.

ThisisthecommonformofatwohandedProcesschartrecordingtheactivitiesoftheoperatortoanalyze.

MultipleActivityChart:-Worker-Machineprocesschartandgangprocesschartfallinthecategoryofmultipleactivitycharts.Aworker-machinechartisusedforrecordingandanalyzingtheworkingrelationshipbetweenoperatorandmachineonwhichheworks.Itisdrawntotimescale.Analysisofthechartcanhelpinbetterutilizationofbothworkerandmachinetime.Thepossibilityofoneworkerattendingmorethanonemachineisalsosoughtfromtheuseofthischart.

Agangprocesschartissimilartoworker-machinechart,andisusedwhenseveralworkersoperateonemachine.Thecharthelpsinexploringthepossibilityofreducingboththeoperatortimeandidlemachinetime.

Themultipleactivitychartisusedwheneveritisnecessarytoconsideronthesamedocumenttheactivitiesofasubjectinrelationtooneormoreothers.Byallottingseparatebars,placedagainstacommontimescale,torepresenttheactivitiesofeachworkerormachineduringtheprocess,themultipleactivitychartshowsclearlyperiodsonineffectivetimewithintheprocess.Thismakestheavoidanceofsuchtimebyrearrangementofworktoamucheasiertaskwhileconsideringcostaspects.

Thischartisusefulwhileutilizinganexpensivemachineorequipmentandwhileorganizingteamwork.Itenablescomplexprocesstoberecordedinasimplewayforstudyleisure.

Workerandmachineactivitiesarenormallyrecordedbyshadingtherespectivebars.Directorprerecordedtimingscanensurethecharteffective.Activatesareplottedagainstthetimescaleandasummaryofthepresentorproposedmethodswiththeirpercentileshouldbemadeforeasyanalyzing.Asampleisshownasontheabove.SimultaneousMotionCycle(SIMO)Chart:ASimochartisanotherLeft-HandRight-Handchartwiththedifferencethatitisdrawntotimescaleandintermsofbasicmotionscalledtherbligs.SIMOChartsareoftenbasedonfilmanalysisusedtorecordonacommontimescalethetherbligsorgroupsoftherbligsperformedbydifferentpartsofthebodyofoneormoreworkers.

SIMOChartisthemicromotionformofthemantypeflowprocesschart,becausetheyareusedprimarilyforoperationsofshortduration,oftenperformedwithextremerapidity,itisgenerallynecessarytocompilethemfromfilmsmadeoftheoperationwhichcanbestoppedatanypointorprojectedinslowmotion.Itisrecordedbya“winkcounter”placedinsuchapositionthatitcanbeseenrotatingduringthefilminginoldendays.Nowduetodigitalfilmwecanusesoftwareforcountingframespassed,ortimeelapsedinsteadof

winkcounters.Investigationinthisdegreeofdetailisonlyjustifiedwhenthesavingresultedfromimprovedmethodwillcontributethecostofworkinvolved.

SIMOCHART

No&Name:Operation:Operator:OperationNo:FilmNo:ChartNo:Date:Chartdoneby:

LeftHandDescriptionTimeinRightHandDescription2,000/mTherbligsExplained:itisthenamedbyMr.FrankBGilberthtoeachofthespecificdivisionsofmovement,accordingtopurpose.Thesetherbligscovermovements,orreasonfortheabsenceofmovement.EachtherbligshasspecificColour,symbol,andletterforeasyrecordingpurpose.AftertheASTM’sAdditionof‘HOLD’inthe1940’sthereareeighteentherbligs.

Initssimplestform,therbligssymbolscanbeusedinplaceofprocesschartsymbols,toproduceatherbligschart.Thiscanservethesamepurposeastheflowprocesschartortwohandedprocesschart.Andalthoughitmayseemthatgreaterdetailscanbeportrayedinthisway,theabsenceofatimescalemakesthisadvantageuncertain.Mostlywedoestherecordedmovieanalyzingtopreparethetherbligschart.Nowadayseitherawinkcounteroramicrochronometer(decimalminutes)areusedtorecordthetime.When,thetherbligssymbolsareshowninthefigure.

MovementandFlowActivities.

Theprocessflowchartsshowsthesequenceandnatureofmovements,butitdoesnotshowclearlythepathsofmovement.Thereareoftendesirablefeaturessuchasback-tracking,congestionandunnecessarylongmovements.Torecordtheseundesirablefeatures,representationoftheworkingareaintheformofflowdiagrams,stringdiagramsortwoandthreedimensionalmodelsmaybeused.

Thesemethodshelpstoreduceproblemsinplantlayoutanddesigneffectivelyandtodemonstratetheimprovedmethodtobothworkersandmanagement,asitisessential.

FlowDiagrams:Theyaredrawings,substantiallytoscalewithworkingarea,showingthelocationofvariousactivitiesidentifiedandnumberedaccordingtosequenceandisassociatedwithaparticularflowprocesscharteitherman,materialorequipmenttype.

Theroutesfollowedintransportareshownbyjoiningthesymbolsinsequencebyalinewhichrepresentsthepathofmovementoftheconcernedsubject.Thesubjectmaybemachinemovement,ormanmovementwithmaterialormaterialmovementonlyaspertherequirement.

Therearetwomethodsusedtopreparetheflowdiagrams,ElevationflowdiagramandThreeDimensionalflowdiagrams.

Asdistancesmovedonaverticalplaneorinahorizontalplane,flowdiagramsarepreparedtoshowtheelevationaswellasplanoftheareawherethemovementoccurring

isplotted.Whenobjectcoversseveralfloorlevelsorthroughdifferentareasofthefactory,athreedimensionalflowdiagramismoreuseful.Theflowdiagramsgiveslayoutofworkplaceandthetravelroutesofworkers,materialorequipment.

A

B 2

1

C

D

StringDiagram:thestringdiagramisascalelayoutdrawingonwhichalengthofstringisusedtorecordthepatternofmovementofaworker,orequipmentworkingwithinalimitedareaduringacertainperiodoftime.Itisdefinedasthescalemodelonwhichthreadisusedtotracethepathormovementofmanandmaterialsduringaspecifiedsequenceofevents.Asathreadisusedtomeasuredistance,itisnecessarythatthediagramshouldbedrawnuptoscale.Thebasicconstructionstepsareatfirststepistomakeastudyofthemovementsofvariousresourcesofthetask.Thenpreparescalelayoutoftheshopareaandmarkvariousfeaturessuchasmachinery,workstations,storesetc.careshouldbetakentoincludeallbuildingfeaturessuchaswalls,anddoorways,blockplansofmachinesandotherequipmentinstalledinvicinityoftherouteandinscale.Thenmarkandinsertpanelpinsatallworkstationsbetweenwhichjourneysaremadeafterattachingitonaboard.Morepegs/pinsmaybestretchedinbetweenthefacilitiestotracemoreorlesstheactualpathfollowedbymenandmaterials.Astrongun-stretchableoftencoloredstringisthentiedtothestartingpointpinandthenbyreferencetothestudytakenroundeachoftheotherterminalsinorderandsequenceofmovement.Usedifferentcoloredstringsfordifferentmanofmaterialmovementstofind

outjourneysbetweenanynumbersofpins.Sincethreadisusedinsteadofdrawlines,thereisnoriskthatobliterationwilloccur.Thenremovethestringafterthepathbeingphotographedandmeasuretocalculatethedistanceorlengthofthemovement.

Themajorusesofstringdiagramare,Itrepresentstherecordofanexistingsetofconditionsandthushelpsthemethodengineerinvisualizingtheactualsituation.Itindicatescomplexmovements,backtracking,congestion,bottlenecksandoverandunderutilizedpathsontheshopfloor.Itisanaidforcomparisonbetweenlayoutsormethodsofdoingajobasfarasthedistancemovedareinvolved.Ithelpsintrackingexistingpathsofmovementforincorporatingnecessarymodification,ifany.Itisprefixedwhenmovementsarenotregularasfarasfrequencyanddistancemovedareconcerned.Stringdiagramindicatesthepatternofmovementsandthushelpsindecidingthemosteconomicalroutestoperformaparticularoperation.

Tosummarize,theprincipaluseofastringdiagramaretoinvestigatemovementinthefollowingcircumstances:1)Whenatramisworking2)Whenoneworkeristendingseveralmachines3)Inprocesswhereseveralsub-assemblieshavetobemovedtoanotherassembly4)Wheretheprocessnecessitatestheworkermovingfromoneworkplacetoanother.5)Fortestingtherelativevaluesofdifferentlayouts.Andalsotodecidehowthematerialormantohavetheirmovementinthefloor.Sometimesaslightchangesofworkstationsmayalsobedecidedusingthischart.

TravelChart:-incertaininstanceswhenitisrequiredtoexaminecomplexinter-departmentalorintersectionmaterialsmovement,theflowdiagrambecomesamazeoflinesanddifficulttofollow.Inparticulartheflowdiagramisnotsuitablewhenquantitativefactorsasdistance,weightandfrequencyofmovementhavetobestudied.ItisalsocalledasFrom-To-Chartsorcrosscharts,sinceitdepictstheentirematerialsflowamongstthedepartmentstakenassourceanddestination.Thetravelchartisofsignificanthelpinproductlayout.Itshowsthematerialinterfacebetweendepartments.Thehighertheinterface,closerthedepartmentsareplacedtoavoidunnecessarymaterialhandling.ToRawDept.Dept.Dept.InspectionFinishedmaterial#1#2#3&QCGoodsStoreFromStore

Rawmaterial80002000StoreDept.#14000200010001000Dept.#230003000Dept.#350050040005000Inspection&QC1000Mij8000

FinishedGoodsStore

MijisinkilogramsTheentriesinthechartarescatteredonboththesidesofthediagonal.AtoBandBtoAtravelrequirementsmaybedifferent.Thetravelchartshavethefollowingmerits.

1)Usefultoolofmaterialsmovementanalysis2)Usefultolocateactivities,3)Alternativeflowsandlayoutscouldbecompared4)Relationshipofactivitiesintermsofvolumeofmovementbecomeclear5)Showsquantitativerelationship.

ActivityrelationshipChart(RELCharts):-arelationshipchart(REL)isacentraltechniqueinaSystematicLayoutPlanning(SLP).Theactivityrelationshipdiagramconvertsvowel-letterratingsontherelationshipcharttoagraphicvisualizationofdesiredclosenessamongactivityareas.Inthespacerelationshipdiagram,eachactivityareaisdrawntoscale,thusshowingtherelativesize(andsometimestheshape)ofeacharea,aswellasitsbest-relatedposition.Arelationshipchartmaybeconstructedasfollows,Listalldepartmentsontherelationshipchart.Conductinterviewsorsurveyswithpersonsfromeachdepartmentlistedontherelationshipchart.Thendefinethecriteriaforassigningclosenessanditemizeandrecordthecriteriaasthereasonforrelationshipvalues.Andthenestablishtherelationshipvaluesandthereasonforthevalueforallpairsofdepartments.Itisimportanttoalloweveryonehavinginputtothedevelopmentofarelationshipcharttoevaluateanddiscusschangesinthechart.Anexampleisshowas,

A=absolutelynecessaryE=especiallyimportantI=importantO=ordinaryclosenessU=unimportantX=undesirable

AnActivityRelationshipDiagramisdevelopedfrominformationintheactivityrelationchart.Essentiallytherelationshipdiagramisablockdiagramofthevariousareastobeplacedintothelayout.

Thedepartmentsareshownlinkedtogetherbyanumberoflines.Thetotalnumberoflinesjoiningdepartmentsreflectsthestrengthoftherelationshipbetweenthedepartments.E.g.,fourjoininglinesindicateaneedtohavetwodepartmentslocatedclosetogether,whereasonelineindicatesalowpriorityonplacingthedepartmentsadjacenttoeachother.

ThenextstepistocombinetherelationshipdiagramwithdepartmentalspacerequirementstoformaSpaceRelationshipDiagram.Here,theblocksarescaledtoreflectspaceneedswhilestillmaintainingthesamerelativeplacementinthelayout.ABlockPlanrepresentsthefinallayoutbasedonactivityrelationshipinformation.Ifthe

layoutisforanexistingfacility,theblockplanmayhavetobemodifiedtofitthebuilding.Inthecaseofanewfacility,theshapeofthebuildingwillconfirmtolayoutrequirements.

ItisimportanttodoproperanddetailedanalysiswhilepreparingtheRELchart.If,insteadofthefacilitiesplannersynthesizingtherelationshipamongdepartmentsasdescribedabove,thedepartmentheadsareallowedtoassigntheclosenessrelationshipswithotherdepartmentstoreducetheconflicts.TherelationshipvaluesbetweenthedepartmentsAandBaretobethesameasthoseofBtoA.itisimportanttoemphasizethedifferencebetweenrelationshipvaluesU(unimportant)andX(undesirable).TwodepartmentscanbeplaceadjacenttoeachotherwitharelationshipvalueU,buttheycannotbeplacedadjacenttoeachotherwitharelationshipvalueX.Fromfacilitiesplanningperspectiveactivityrelationsareoftentranslatedintoproximityrequirements.Forexample,iftwoactivitieshaveastrongpositiverelationship,thenitishighlydesirablethattheybelocatedclosetogether.

SpaceRequirement.

Plantlayoutprimarilydealswiththeallocationofthetotalfloor,rathercubicareaamongvariousproductionandservicedepartmentsalongwiththeirspecifiedstationinginsidetheplantarea.Themostdifficultdeterminationistheamountofspacerequiredinthefacility.Thedesignyearofafacilityistobefora5to10yearspaninfuture.Considerableuncertaintygenerallyexistconcerningtheimpactoftechnologyinmostindustries,changingtheproductmix,demandlevelsarethemajorchallengeswhileplanninganapparelindustry.ThesecondchallengeisthetaskofprojectingTrueSpaceRequirementsfortheuncertainfuture.Tofurthercomplicatematters,thereexiststhe“Parkinson’sLaw”.Looselytranslatedinthecontextoffacilitiesplanning.Itstatesthatthingswillexpandtofillallavailablecapacitysoonerthanyouplan,hence,eventhoughthefacilitymightbeconstructedwithsufficientspaceforfuture,whenthefuturearrives,therewillbenospaceavailableforit!Indeterminingthespacerequirementforwarehouseactivities,inventorylevels,storageunits,methodsandstrategies,equipmentandrequirementsmustbeconsideredindetail.

Inmanufacturingandofficeenvironments,spacerequirementsmustbedeterminedfirsttotheindividualworkstationsforeachandthendepartmentalrequirementsbasedonthecollectionofworkstations.ForexampletheworkstationrequirementforaPatternmakerandthatofasampletailorarenotequal,thepatternmakerneedsalargesizedtablewithsufficientrackswhereasasampletailorwithsufficientmachineandsitingspaces.AccordingtoJamesLundy“Overallplantareasaregenerallyabout150to200sq.feetperemployeeforalightmanufacturingoperations,500sq.feetformediummanufacturingandashighas1000sq.feetforprocessindustries.

FactoryandDepartmentalLayout

Thelayoutofthefactoryisofmajorimportanceasitaffectstheflowofmaterialandprocesses,labourefficiency,supervisionandcontrol,useofequipment,useofspace,expansionpossibilities,andfactoryappearance.Whenproperlyexecuteditpreventswasteoftime`unnecessaryeffort,andlossofmoneyduetouselessmovementandtravelofworkinprogress.Itincreasesworkersefficiencyandsatisfactionasitfreesthemfromtakingunnecessarystepsormakingneedlessmotionsandpermitsthemtodirecttheirenergyintoproductiveefforts.Itassistsmanagementinmaintainingorimprovingtheestablishedqualityoftheproduct,inmeetingdeliveryschedulesandthusinestablishingbetterrelationshipswithcustomers.Itpreventstheneedlessduplicationofmachineryandequipment,andthiskeepsthecapitalinvestmentataminimum.Itconservesfloorspace,thusreducingtheinvestmentinplantandincreasestheefficiencyofoperation.Itmakesprovisionforexpansionandfortemporarycontractiontotakecareoffluctuationsinmarketdemand.Itprovidesandorderlyplantarrangement,thatispleasingtolookatandasafeplaceinwhichtowork.WithintheworkingcareerofanIndustrialEngineer,itishighlyunlikelythattheopportunitytoplanthelayoutofthecompletefactorywillarise,buthe/shemayberequiredtore-organizemanufacturingsectionswithinthepresentfactory.IfwefollowthebasicguidelinesofMethodStudy,wecanadaptthesetosuitthecriteriaofasuccessfulfactorylayout.Althoughthechoiceofselectingtheparticularareaofthefactorythatweareorganizingmaywellbedoneforus,thenextstageistherecordingofalloftheinformationwewillneed.Record:Thefirstcriteriaisgoingtobethephysicaldetailsaboutthefloorspaceavailable.Althoughthemeasurementsofthespaceavailablemaywellbeobtainedfromthearchitectsplan,orbytakingmeasurements,itisimportanttorememberthattheavailablespacemaybereducedbyfactorssuchasentrancesandexitsfromthefloor,columnsandobstaclesofapermanentnature,sothattheavailablespacemaybeconsiderablylessthantheareameasured.Wecantermthistheavailableworkingarea.Secondlywewillneedtocontrolalltheinformationabouttheparticulartypesofmachineswewillbeusingandthenumberofmachinesrequiredtomeetourproductionrequirements.Thephysicalsizeofthemachineswillhavetoberecordedandalsotheamountforfloorspacerequiredforthemachineandfortheoperatortobeabletopositionthemselvescomfortablybehindit,andthespacerequiredbetweenmachines.Thirdly,wemustrecordalloftheparticularsaboutthegarmentsthatarebeingmade.Thesequenceofoperationsandhowweintendtomovegarmentsthroughtheprogressivestagesofassembly.Thiswillnecessitateassessingwhattypeoftransportationsystemweintendusing,ifany,orthesizeofbasketsortrolleys,ifweusethem.Workinprogress

willalsobeanotherfactorthatwillaffecttheavailableworkingareaanditisnecessarytodetermineatanearlystage,whatourquantitiesofworkinprogresswillbe,sothatadequatespacecanbemadeforstorage.Nextwewillneedtoknowthenumberofoperators,supervisorsandservicehandswhoaregoingtoworkinthearea,astheymustbeprovidedwithadequateaccessintoandoutofthefactory,toiletandcanteenfacilitiesandofficecommunication,fortheindirectworkersandstaff.Recordtheservicesrequiredforthemachinesandpeopleinthefactory,howmuchelectricityisrequiredforlightingandpower,howmuchwaterandcompressedair,ifneeded.Thesefactorsmaywellhaveamajorinfluenceonthelayoutofalotofmachinery,astheavailabilityofpowerpointsandsteam,forexample,arenotasmaneuverableasthemachinery.Recordtheactualrequirementsofthebuilding.Thesewilltoagreatextentbecoveredbythe“FactoriesAct”.Tosummarizeontherecordingaspects,itisapparentfromtheinfluencesthattheprocesseshaveonplantlayout,itisnecessarythatathoroughproductionanalysismustbemadeofthegarmentsandtheoperationsrequired,todeterminethemostadvantageousfordepartmentsandmachinery.Tothisendtheflowofworkmustbeknown,theprocessthroughwhichthegarmentsmustpassbedetermined,thesequenceofoperationsbeestablishedandtherequiredmachineryandequipmentbeselected.

Thereforetheinformationrequiredtobeknownbeforeplanningcanbelistedasfollows:

1.Thetotalworkablefloorareaavailable,2.Theoperationsrequiredtomanufacturethegarments,3.Thesequenceofoperations,4.Themachineryandequipmentrequired,5.Howthegarmentsaregoingtobehandled,6.Thenumberofoperatorsandstaffrequired,7.Whattypeandamountofservicesrequired.Examine:Onceallofthefactspreviouslydiscussedhavebeengathered,theymustthenbecarefullyexamined.Thisisdonetoensurethatnothingthataffectsthelayouthasbeenmissed;rememberitwillbetoolateoncetheplanisdrawn,andalsotoseewhatfactorshaveaninterrelationship,ie,canwepositionmachineswherewewant,irrespectiveofwherethepowersourceis,ordoesthelocationofthepressingsectiondependonwherewecanlocateorsteampipes.Develop:Thenextstageinthelayoutofourfactoryistodevelopanddrawtheactualplan.Itisimperativethatweensurethateachdepartmenthasadequatespaceforitsneeds,andanallocationofspacetomeetanypossibleexpansioninthefuture.Toenableustomeetanypossibleexpansioninthefuture.Toenableustodothiswemustprepareablockplan.Thisisaplanoftheactualallocationoffloorspacetoeachdepartment,andtherelationshipofthedepartmentstoeachotherpriortothedetailedplanningofeachsection.Intheblockplanwemustensurethatadequategangwaysandpassageshavebeenleftfortheflowofworkandpeople,andwherepossibleonedepartmentfeedstothenext,therebyhelpingtheworkflowfromdepartmenttodepartment.Thenextstageisthedetailedplanningofeachdepartmentandthepositioningofthemachinery,tablesandequipmentetc.thataretobeused.Althoughwenowhaveadetailedscaleplanofthefactory,alotoffactorsstillhavetobeconsideredbeforewecandrawinthepositionsofthemachinery.Scaletemplates,preferablyofstiffcardboard,shouldbe

madeandpositionedontotheplanwheretheyarerequired,usePre-sticktopositionthetemplates.TheFactoryorProductionManagershouldbeinvolvedasultimatelytheyarethepeopleresponsiblefortherunningofthefactory.Themechanicshouldalsobeconsultedashe/shewillhavethetechnicalcompetencetogiveadviceonpowersupplyetc.Thesupervisorsofthedepartmentsshouldbeinvolved,theyhavetoruntheirsectionsonadaytodaybasis.Itmustalwaysberememberedthattheinstallationofthelayoutisadisruptingtimeforemployees.Whentheinstallationplansarenearingcompletion,inviteemployeestocomeinandseethelayout,andidentifyeachdepartmentorworkstation,sothattheworkerscanseewheretheyaregoingtobesituatedandinvitetheircommentsoropinions.Thefinalstepindevelopingtheplansistomakeatimetableofthemovesandascheduleofhowthechangeistobeimplemented.Install:Thenextstageistheimplementationoftheplan.Nowtheplanhasbeendrawn,theEngineerwillusuallyonlyactasadviserorcoordinator,asthemechanicsormaintenancedepartmentwillbetheonesinvolvedinthephysicalmovingoftheequipmentispositionedexactlywhereitisintended.Thiscanbehelpedbymarkingthefloorandmachinerywithchalk.Thisisausefulguideforthemaintenancecrewtopositionthingscorrectly.NB:Itisimportanttonotethatonlyonepersonshoulddirectamove.Ifmorethanonepersonisgivinginstructions,confusionwilloccur.

SectionLayoutApreviouslystateditisveryraretheopportunitywillariseforanIndustrialEngineertoplanthelayoutofawholefactory.Itishighlylikelythoughthathe/shewillbecalledupontoreorganizeaparticularsectionwithinthefactorytoaccommodateastylechangeforexample.TherulesgoverningSectionLayoutarethesameasthosefortheFactoryLayout,butonamoredetailedscale.Onceagainweneedtorecordalltherelevantinformation,firstlyabouttheactualproductwewillbemaking:

1.Howmanystyles,3.Numberofcomponents,5.Sizeofbundles,7.Whatfuturechanges.2.Productionrate,4.Numberandsequenceofoperations,6.Anyspecialtrimmings,

Secondlyabouttheequipmentthatwewillbeusing:1.Howmanymachinesrequired,3.Powersupplies,5.Sparemachines,7.Lighting,2.Whattypeofmachines4.Compressedairorsteam,6.Specializedmachinery,8.Futurechangesoradditions.

Lastlyweneedtorecordthespaceavailable,andagaincalculatetheworkablefloorspaceavailablebytakingintoaccount:1.Gangways,2.Pillars,3.Exitsandentries,4.Spacebetweenmachines.

Nowweneedtodeveloptheplanagain.Usingtemplatesofthemachinesisanidealwayforpreparationbeforeactuallydrawingtheplan.Itmustbedecidedfromthestartwhat

typeofproductionsystemwearegoingtouse.Thiscouldbe;Makethrough,Straightlineorconveyorsystem,ConventionalBundleUnits(CBU),ProgressiveBundleUnits(PBU),Andifweneedtablesformatchingpointshowmanyandofwhatdimensions.TheProductionsystemsindetailwillbeexplainedlattersessions.

Install:Theimplementationoftheplanagainfollowsthesamerulesandproceduresasthatofthefactoryonlyonasmallerscale.Arethemanagers,supervisors,mechanics,etc.,completelyfamiliarizedwiththechangeover?Havethemachinesbeenmarkedtowheretheyhavetobepositioned,andisthepowersupplyavailableandadequate.Whenmarkingmachinesitisagoodideatonumberthemachinesandthefloorposition.Itisimportantthattheoperator’schair,cushionandworkboxandanyotheritemswhichtheoperatormayuse,sothatwhenhe/shegetstotheirworkplaceeverythingisavailableforthem.Thisminimizestheeffectofmovingandhelpsthemtosettlemorequickly.

Maintain:ThemaintenanceofSectionLayoutcanconcernitselfwithensuringthatallthemachinesareworkingproperlyand,vitallyimportant,istheworkflowingfromoperationtooperationasrequired,aretheworkinprogresslevelscorrectandhasthenewlayoutcreatedanyunforeseenbottlenecksordisruptions.Workshouldnotbemovedtooperators.Operatorsshouldbemovedtothework.Thiswillenablesupervisorstoseewheretheworkinprogressis,andwillensuresimplersupervision.Itisimportanttoestablishagoodaestheticlooktoalayout,peopleworkbetterandmoreefficientlyinawellorderedandcleanlayout.Example:considertheconditionthatweareworkingonarentedbuildingandrecentlywehavepurchasedanewbuildingandwehavetoshiftthecurrentfactorytothenext.Wehavecalculatedthecurrentspaceutilizationpercentageofthefactoryandthesametobefollowedtothenewone.Thedataare,

1)Cuttingroom-12.59%2)RawMaterialStore-9.6%3)3Sectionseachof-9.6%4)Canteen-8.33%5)FinishingDepartment-8.67%6)Dispatch-11.2%7)Offices-8.5%8)Gangways-12.31%

Finishi

Thebelowshownisa2basicplantlayoutbasedonthedata,CalculatedasTotalArea=75x100=7500sq.feet,anditsproportionateallocationofeachdepartmentwithrespectivetoitsRELstrengthareallocated.Itisinevitabletopreparetheblueprintsandmodelsoftheplantlayoutbeforetheactuallayingfunctionbegins.Thelocationofthemachines,equipmentandplantfacilitiesistheresultoftrialanderrormethod.Templatesormodelsrepresenttheactualspacerequirementforeachmachineorservicedepartmentalongwithitssequentialrelations.Thepopularmethodofplantlayoutare,Squarelayout,TemplatelayoutorTwo-dimensionallayout,ModelLayoutorthreeDimensionalLayoutetc.SquareLayoutisthepreliminarylayoutoftheplant.Itindicatesthetotalsquarefeetfloorareaanditsallocationamongvariousworkstationsandtheplantfacilitiesonthebasisofsomeappropriatescale.Itsimplyindicatesthelocationofworkstation,plantfacilityandflowpatternsofmaterials.Thisisthebasisfortheothertwolayouts.TemplateLayoutisthemostcommonmethodofpresentingtheplantlayout.Theyaretwo

dimensionalandconsidertheheightofthefloorarea,generally,cardboard,hardboard,coloredpapers,tapesetc.areusedinpresentingthebuildingwalls,workstations,plantfacilitiesetc.atemplateisgenerallypreparedtoascale¼inchequaltoonefoot.Theyarecharacterizedbytheirtransparency.Itischeapertomodellayout,itispossibletoproduceduplicatecopiesthereof,hasclearreadingandinterpretation.Modellayoutorthreedimensionalmodelaremadeusingmodelsofplantandequipmentwiththeirappropriatescale.Generallymodellayoutsarepreparedtothesamescaleastemplatelayout.Theyaremostexpensiveandveryrarelyused.Theseareeasymodelstoexplainandprovidesvisualaidandhascleanpossibilityofoverheadworkstationmodeling.ADLEP(AutomatedlayoutDesignProgram)andCORELAP(ComputerizedRelationshipLayoutDesigning)areRELbasedcomputerprogramsandCRAFT(ComputerizedrelativeAllocationofFacilitiesplanning)minimizeslinearfunctionofmovementsamongstdepartmentsandisanimprovementprogram.AlsotherearelotothersoftwarebasedonthesemethodsGSD,PROSMVetc.haveadvancedfeaturesattachedtothecoresoftwaretodothelayoutplanning.

MaterialHandling

Materialhandlingisanecessaryandsignificantcomponentofanyproductiveactivity.Itissomethingthatgoesonineveryplantallthetime.Inamanufacturingfirm,therawmaterialsareobtainedfromthesuppliersarestoredinthestoreroom.Theyareissuedtoproductiondepartmentandaremovedinsidetheplantareafromoneprocesstoanotherfortheproductionoperationstilltheybecamefinishedproductsreadytodispatch.Foragarmentindustry,whenweconsiderthetotalcost,itisabout60%to80%costarespentforthefabricitself,anditismovedtillthedispatchroomthroughmanystages.Veryreductioninmovementisreductionincostofmanufacturing,henceaproperstudyshouldbemadebeforeadaptinganysystem.Materialhandlingmeansprovidingtherightamountoftherightmaterial,intherightcondition,attherightplace,attherighttime,intherightpositionandfortherightcost,byusingtherightmethod.Itissimplypickingup,moving,andlyingdownofmaterialsthroughmanufacture.Itappliestothemovementofrawmaterials,partsinprocess,finishedgoods,packingmaterials,anddisposalofscraps.Ingeneral,hundredsandthousandstonsofmaterialsarehandleddailyrequiringtheuseoflargeamountofmanpowerwhilethemovementofmaterialstakesplacefromoneprocessingareatoanotherorfromonedepartmenttoanotherdepartmentoftheplant.Thecostofmaterialhandlingcontributessignificantlytothetotalcostofmanufacturing.Inthemoderneraofcompetition,thishasacquiredgreaterimportanceduetogrowingneedforreducingthemanufacturingcost.Theimportanceofmaterialhandlingfunctionisgreaterinthoseindustrieswheretheratioofhandlingcosttotheprocessingcostislarge.Todaymaterialhandlingisrightlyconsideredasoneofthemostpotentiallylucrativeareasforreductionofcosts.Aproperlydesignedandintegratedmaterialhandlingsystemprovidestremendouscostsavingopportunitiesandcustomerservicesimprovementpotential.It’sawell-knowntheory:Sewingfactoriesspend80percentoftheirtimehandlingproductvs.20percentoftimesewing,pressingorfinishing.Ifthetheoryholdstrue,thatmeansthereareonlysixminutesofproductive,value-addedworkina30-minutegarment.Theother24minutesareunproductive,spentmovingandmanipulatingmaterialsothatthe

productiveworkcanbecarriedout.Considerthisbreakdownofthestepsinvolvedinclosingoftwosideseams:

“Materialhandlingisthemovementandstorageofmaterialatthelowestpossiblecostthroughtheuseofpropermethodandequipment”

Pickupfirstpart,pickupsecondpartandpositiontwopartstogetheratbeginningofseam,placetoneedle.Sewseaminthreebursts(threeburstsrequiredtorepositionfabricasonesewsalongtheseam).Repositiontwopiecestogetherforsecondseam,placetoneedle.Sewseaminthreebursts(againthreeburststoallowforrepositioningasonesews).Fold,setasideandbookwork.

It’saverysimpleoperation,butimmediatelyoneseesthattheonlyproductivepartistheactualsewing,nottherepositioningduringtheseam,notthepickingupandplacingofthefabricstotheneedle,notthefoldingandsettingasideandnotthebookingofthework.

Methodsofmaterialshandlingcansubstantiallyincreasetheineffectivetime.Forinstance,itisnotproductivetohaveemployeesorsupervisorswhoseresponsibilityitistomoveworkaroundtodifferentpartsofthefactory.Likewise,foldingandunfoldingworkbetweenoperationsisnotproductive.Tyingupanduntyingbundlesalsoisawasteoftime.Yetmanycompaniescontinuetoperformtheseactivities,whichcostmoney,andthereforedrainprofitability.Theyalsotaketime,thushamperingacompany’sabilitytorespondquicklytocustomerneedsandmarketrequirements.Ifmovingworkfromoneworkstationtoanotherisunproductive,thestorageofworkbetweenoperationsisevenworse.Noincomecanbeobtainedfromthatworkuntilitisfinishedandreachesthecustomer.

Increasingglobalcompetitionisforcingmanufacturersaroundtheworldtolookseriouslyattheirmethodsofproductioninthequestforwaystoturngoodqualitymerchandiserapidly.Theyareseekingflexiblemethodsthatwillenablethemtoreacttoconsumerdemandsandmaintainlowwork-in-process(WIP)levels.Tobeabletoswiftlychangestylesinaquick-turnmanufacturingenvironment,companiesmustembracemarket-orientedproduction.Itisvitaltomastersimultaneoushandlingofdifferentproductionprocessesandparallelchannelingofstyles.Fromafinancialperspective,thisbusinessmodelfocusesholisticattentiononthecostofdelaysandtheamountofworkingcapitaltiedupinWIPandstock.Intraditionalproductionmodels,theretendstobemoreofanisolatedfocusonlaborcosts.Intheirpushtobemoreflexible,somecompaniesaremovingtowardToyotaSewingSystem-style(TSS)quickresponsemethods.InaTSSenvironment,operatorsworkinteamstofinishsewingasinglegarment,movingbetweenmachinesandoperationsandmanuallypassingthegarmentontothenextoperatorimmediatelywhensheisfreetoprocessit.ThismethodresultsinnoWIPbetweenoperations,andtheoperators’workimmediatelyresultsinafinishedgarment.A60-minutegarmentproducedbyaTSSteamshouldtake60minutestomovethroughtheTSSsewingunit.Forcomparison,a10-minutegarment,withaweek’sWIPinthesewingroom,couldtakeaweektocomplete.

AnotherapproachtoeliminatingwastedtimeandexcessiveWIPbuildupistheuseofunitproductionsystems(UPS).Thesesystemseliminatetheneedforoperatorstobundlegoodsorcollectordisposeofwork,andgarmentsareergonomicallydeliveredtothe

operator’sneedlepoint,readyforsewing.StudiesindicatethatUPScanchangean80/20handlingtoproductionratioto60/40orbetter.

Itisagoodideatogenerateworkflowandfactoryfloorlayoutdiagramsinanalyzingyourneedsandobjectivesforanewmaterialshandlingsystem.Youranalysisshouldtakeintoconsiderationtheproductmix,fabrictypes,ordersizeandqualitylevelyourfactoryismakingandexpectstomakeintheforeseeablefuture.Timeshavechangedfromwhenonelinecouldbesetuptomakeoneproductforeternity.Flexibilityisnowparamount.Manycompaniesthatsetupoverheadrailsystemswithoutbypasseshavehadtorethinktheirsituationsjustasmuchascompaniesthatarestillusinglargebundletruckstomovematerials.MaterialsHandlingSolutionsAvailable

Allsorts,shapesandsizesoftrucks,binsandboxesfromnumerousnon-clothingindustry-specificsuppliers.Boxescanbeself-stackingorusedincombinationwithtemporarystorageracking.Trolleyscaneasetransportation.

Awidevarietyofsewingroomtrucks,trolleysandmobilerailswithadd-onshelves,small-partbaskets,etc.Designoftheseproductsdependsonthetypeofproducttobemanufactured.Manyincorporateclampstosecuretheworkinapositiontoenablemachiningprocessestobecarriedoutwithaminimumofhandling.Caremustbetakeninthechoiceoftrucksandtrolleystoensurethewheelsaredesignednottobecomecloggedwiththread,dustandlintfromtheshopfloor.Numerousdifferentdesignsofclampsandclips,whichcanbeincorporatedintooff-the-shelfsolutionsorin-housedevelopments.Thefabricandgarmenttypewilldictatewhatsortofclamp/clipisused,dependingonthefabricsorgarment’sweight,delicateness,slipperinessandtendencytotearorstretch.Oftentrialswillberequiredofseveraltypestodeterminethemostsuitable.Floor-mountedconveyorsusingthelivestorage,flowlineorcarouselprinciple.Theseconveyorscanbepoweredormanuallymoveable.Numeroustypesofmanualoverheadhangingsystemsforprogressingsinglegarments,bundlesoracombinationofboth.Althoughgarmentpartsarenormallyattachedinahangingpositionusingclamps,somesystemscatertoflatgarmentsbyusingahangingbasketforsomeoralloftheprocess.Althoughmanyoff-the-shelfsystemsareavailable,manycompaniesdeveloptheirownin-housesolutions,eitherindependentlyorwiththeassistanceofindependentconsultantsorcompaniesspecializinginmaterialshandling.Differentsolutionsmaywellbeusedindifferentareasofthefactory,dependingontheproductandprocess.Forexample,pre-assemblyareasmayworkinlayheight,mainassemblyareasinbundlesandfinishingdepartmentsinsingles,eachrequiringadifferentmethodofhandling.Whateversolutionischosen,greatcaremustbegiventocarefulplanningoftheinstallationandimplementation,withadequateandcorrecttraininggiventoallpersonnelinvolved.Oncethesystemisupandrunning,itsusemustbecorrectlymaintained.Also,operators,supervisorsandmanagementalikemustnotslipbackintooldmethodsandhabits,orintroducenewelementsunlessthereisagoodreasonfordoingso.

Overheadhandlingsystemscaneasebottlenecks,someoverheadmaterialhandlingsystemsusedingarmentindustryare,Switchtrack:Switchtrackwasdesignedbyproductionengineersforproductionmanagers

whowantedtoincreaseoutputongarmentassemblylinesandmaintainflexibilityforstylechanges.Asamanualsystem,Switchtrackismaintenancefreeandrequiresnospareparts,lubricationorelectricalpower.Aswithallnewsystems,itdoesrequireinitialtraining,whichisprovidedaspartoftheinstallationpackage.Switchtrackalsoprovidesfreeassistanceinlayoutplanning.Switchtrackusesanoverheadaluminumprofilesuspendedonastrongsteelframetocarryachainthroughtheassemblyline.Thechain,withaseriesofclipstoholdthecomponents,thendeliverstheworktotheoperator.Theworkisdeliveredataheightthatenablestheoperatortopresentthemainbodyofthegarmenttotheneedlepointwithouttheneedtoremoveitfromthechain.Anysmallpartsforattachmenttothegarmentcanbeeasilyremovedfromtheclipwithonehandforsewingtothemaincomponent.Whenthesewingoperationiscomplete,theoperatorpushesthechainforwardforthenextoperator.Asthenextoperationisnotalwaysinlayoutsequence,theflickofaswitchcandivertthechaintoabypassfacility.Thisallowsflexibilityonthelineandeliminatespotentialbottlenecks.Switchtrackreportsthatbenefitssuchastheeliminationoftheneedforbundlehandling,sortingbynumbersandhandlingpiecesthatwillbeattachedbysomeoneelseadduptoproductivityimprovementsof15percentto20percent.Thecompanyreportsthesystemcanreducethroughputtimebyasmuchas80percent,thanksinparttoareductioninrework,bettercontrolofworkflowandeasieraccessforrandominspections.Switchtrackproductionengineerscanintroducenewworkingpracticestohelpmaintainhighlevelsofproductivity,resultinginareturnoninvestmentoflessthanoneyear,thefirmreports.

PeterWard:-DuringthepastthreeyearsU.K.-basedPeterWardhasdevelopedamanualoverheadsewingproductionline(patentpending)andduringthelatterhalfof2003,hasbeeninstallingitinfactoriesinMorocco,Indonesia,IndiaandMadagascar.Thelinehastworails,onegivingtheoptiontobypasstokeeptheworkflowing.Thecompanypointstothefollowingadvantagesofthesystem:aspecialballclampunitdesignedtoholdthematerialisveryquicktoloadandunloadanddoesnotmarkthematerial;thecarrierissuitableformostgarments;andthecarrierrotatesandcanbemovedupanddown,allowingeasymovementfromonegarmenttoanother.Aswithothersystems,realtimeproductioncontrolmaybeintroduced.

Somecomparativestudiesshowa15percentincreaseinoutputamongcompaniesusingthePeterWardsystem,whichlikeSwitchtrack,isamanualsystem.Inadditiontosewingrooms,WardhasdesignedandinstalledmanyhandlingsystemsinfinishingandpressingareasbothintheUnitedKingdomandabroad,especiallyinSriLanka.

SalpomecLtd.:Salpomec,asupplierofslidetubegarmenthandlingsystems,specializesindevelopingandproducinggarmentproduction,handling,transportandwarehousingsystemsunderthenameMagicTube.TheMagicTubeenablesthemovementofgarmentsandtheirpartswithouttraditionalwheeledtrolleysorcomplextechnicalsolutions.Thesystemsareinuseinmorethan20countriesandinmorethan200companiesthroughoutEurope,theUnitedStatesandAsia.Salpomecreportsthatitssystemsupportsthekindofproductionthatisbasedonfastthroughputandminimalinventoryonsite.Itreportsthatitssystemsaredesignedtobeergonomicandcomfortablefortheworker.

Thecostofaproductionsystemincludesnotonlytheconveyingsystempricebutalsothetechnicalelementsrequiredtooperateit,suchaslights,electricaloutlets,pressuredair,steamandwasteremoval.MuchsavingscanbehadwhenthesamestructurecanbeutilizedforalloftheseelementsasinthecaseofSalpomec’sMagicTube.Theproductionlinesolutioncanbedesignedasadouble-linesystemwithfixedormoveableworkstations.ItcanbefittedonI,UorSshapes,andcanbefloor,wallorceiling

supported.Salpomec’ssystemcanaccommodatecuttingroomflowandtheneedtoshiptoandfromsubcontractors.Thesystemcanadapttotheneedsofcell,smallgrouporwholesectionproductionofbundlesorunits,andspecialoperationscanbeintegratedintothesystem.Differentsizesofclipsandclampsareusedinhangingcutpieces,garmentpartsandcompletedgarmentsontotheSalpomecsystem’sbasketsandslidingunits.Largepiecesarehungbyclampandsmallerpiecesbyclip.ThebasicprincipleoftheMagicTubeproductionsystemisthatthebundle,garmentpiecesand/orgarmentshouldnotbetakenoffoftheslidingunit,cliporclamp,unlessabsolutelynecessary.Ifaworkstageforcesdetachmentfromthebasketortheframe,mostoftenthecliporclampcanstillbeleftattachedtothebundleorproduct,againsavinghandlingtime.TheMagicTubeproductionsystemcanenableanincreaseof15percentto20percentofoverallproductioninashorttime,Salpomecreports.

EtonSystems:-EtonSystemsisasupplierofautomatedUPS,focusingonthesewnproductsindustry.ItsheadquartersareinSweden,andthecompanyoperateswithdirectsubsidiariesandagentsworldwide.EtonUPSisdesignedtoautomatematerialsflowthroughtheproductionprocessandminimizematerialshandlingforeachsewingoperatorathis/herworkstation.Italsoincorporatesreal-timeproductioncontrol,collectingbothlaborcostandWIPinformationattheworkstation.Usersmaysortproductsbydifferentcriteria,suchassizeorcolor.Productionqualitycanbetracedautomaticallythroughthemanufacturingprocess.TheEtonsystemforapparelindustriesisaflexiblematerialhandlingsystemdesignedtoeliminatemanualtransportationandminimizehandling.Itincreasesproductivityradically,ensuresanoptimalworkingflowandprovidestimeforaddingvaluetoyourproducts.Technicallythesystemconsistsofoverheadconveyorswithindividuallyaddressableproductcarriers,automaticallyfindingitswaytothecorrectoperation.Itismonitoredbyacomputerprovidingallnecessarydataformeasuringand

managingtheprocessoptimally.Furthermore,thesystemishighlyflexibleandcanrapidlybemodifiedtochangesintheproductionlineortheneedforexpansion.Eton’ssoftwareinterfaceswithothersoftware,suchassystemstrackingimportandexportinformation.Thesystemalsocanautomaticallyinfluencepayrollbasedonproductivitydata.TheEtonsystem’sSkillsHistorylogsmeasurethecompetenceofoperators.Supervisorscanaccessinformationregardingwhichoperatorscanperformwhatoperationsandwhoisbestsuitedtotransfertoachievetheoptimalbalancingofthesystem/manufacturingprocess.Eton’slatestdevelopmentisaWeb-basedinterface,calledtheDigitalZone,whichenablescustomerstoviewproductionviatheInternetfromremotelocations.Whileconsideringthemainobjectivesofmaterialhandling,theprimaryobjectiveofamaterialhandlingsystemistoreducetheunitcostofproductionandtheothersubordinateobjectivesare:

1.Reducemanufacturingcycletime2.Reducedelays,anddamage3.Promotesafetyandimproveworkingconditions4.Maintainorimproveproductquality5.Promoteproductivityi.Materialshouldflowinastraightlineii.Materialshouldmoveasshortadistanceaspossibleiii.Usegravityiv.Movemorematerialatonetimev.Automatematerialhandling6.Promoteincreaseduseoffacilitiesi.Promotetheuseofbuildingcubeii.Purchaseversatileequipmentiii.Developapreventivemaintenanceprogramiv.Maximizetheequipmentutilizationetc.7.Reducetareweight8.Controlinventory

Ultimatelythetotalcostofmaterialhandlingmustdecrease,itismostlyinthe,1)Costofthematerialhandlingequipment,bothfixedandoperatingcostcalculatedasthecostofequipmentdividedbythenumberofunitsofmaterialhandledovertheworkinglifeoftheequipment.2)CostofLabour-bothdirectandindirectassociatedcostcalculatedintermsofcostperyearunitofmaterialhandled3)CostofMaintenanceofequipment’s,damages,lostordersandexpandingexpenses,alsocalculatedintermsofcostofmaterialhandled.Aftercalculatingtheindustryrequirements,wherewewanttoautomate(partialofcompleteproductionandprocessline),anditscost,etc.andthenacomparisonchartoftherequirementandreturnoninvestmentgraphscomparisonistobemadeindetailbeforeinstallinganynewsystemtoarunningproductionline.ButwhileplanninganewlineitcanbeplannedonROItimescalebased.NowadaysEtone®aremostusedsystemforitsextendedapplicabilityandotherfeaturesetc.wherewegoforacompletelineautomation.Limitationsofautomatedmaterialhandlingsystems:-Agoodmanagementpracticeistoweighbenefitsagainstthelimitationsordisadvantagesbeforecontemplatinganychange.Materialhandlingsystemsalsohaveconsequencesthatmaybedistinctlynegative.Theseare:

AdditionalinvestmentLackofflexibilityVulnerabilitytodowntimewheneverthereisbreakdownAdditionalmaintenancestaffandcostCostofauxiliaryequipment.Spaceandotherrequirements:

Theabovelimitationsordrawbacksofadoptingmechanizedhandlingequipmenthavebeenidentifiednottodiscouragetheuseofmodernhandlingequipmentbuttoemphasizethatajudiciousbalanceofthetotalbenefitsandlimitationsisrequiredbeforeaneconomicallysounddecisionismade.

EconomicsofMaterialHandling

TheAmericanSocietyofMechanicalEngineers(ASME)haddevelopedcertainformulasforestimatingtheeconomicsthatarepossiblewiththeapplicationofcertainequipmenttomaterialhandlingproblem.Thefollowingfactorsinthehandlingcostaretakenintoaccountare,

1)A=Percentageallowanceoninvestment2)B=Percentageallowanceforinsurance,taxesetc.3)C=Percentageallowanceformaintenance4)D=Percentageallowancefordepreciationandobsolescence5)E=Yearlycostofpower,suppliesandothersinDollars6)S=Yearlysavingindirectlabourcostindollars7)T=Yearlysavinginfixedcharges,operatingchargesorburdenindollars8)U=Yearlysavingorearningthroughincreasedproductionindollars9)X=percentageofyearduringwhichequipmentisused10)I=Initialcostofequipment

Makethrough,Section,PBS,Synchro,QRS,Modular…

3ProductionSystems

Aproductionsystemcomprisesboththetechnologicalelements(machinesandtools)andorganizationalbehavior(divisionoflaborandinformationflow).Businessesneedtodesigntheirownproductionsystemsthisthenbecomesthefocusofanalysis,modelinganddecisionmaking(alsocalled“configuring”aproductionsystem)Afirstpossibledistinctioninproductionsystems(technologicalclassification)isbetweencontinuousprocessproductionanddiscretepartproduction(manufacturing).

1)ProcessProductionmeansthattheproductundergoesphysical-chemicaltransformationsandlacksassemblyoperations,thereforetheoriginalrawmaterialscan’teasilybeobtainedfromthefinalproduct,examplesinclude:paper,cement,nylonandpetroleumproducts.

2)PartProduction(e.g.carsandovens)comprisesbothfabricationsystemsandassemblysystems.Inthefirstcategorywefindjobshops,manufacturingcells,flexiblemanufacturingsystemsandtransferlines,intheassemblycategorywehavefixedpositionsystems,assemblylinesandassemblyshops(bothmanualand/orautomatedoperations).AnotherpossibleclassificationisonebasedonLeadTime(manufacturingleadtimevsdeliveryleadtime)EngineertoOrder(ETO,PurchasetoOrder(PTO),MaketoOrder(MTO),AssembletoOrder(ATO),andMaketoStock(MTS).Accordingtothisclassificationdifferentkindsofsystemswillhavedifferentcustomerorderdecouplingpoints(CODP),meaningthatWorkinProgress(WIP)cyclestocklevelsarepracticallynonexistentregardingoperationslocatedaftertheCODP.Workinprocess,workinprogress,(WIP)goodsinprocess,orin-processinventoryareacompany’spartiallyfinishedgoodswaitingforcompletionandeventualsaleorthevalueoftheseitems.Theseitemsareeitherjustbeingfabricatedorwaitingforfurtherprocessinginaqueueorabufferstorage.ThelesserWIPmeanslesserthematerialinproduction.Mostoftheproductionsystemsemployedinclothingfactoriesarederivedfrommanualormechanicalsystems.Eachproductionsystemhasitsownspecificoperationalcharacteristics.Somegeneralcategoryofproductionsystemsfollowedinapparelproductionareasfollows,

MakeThroughGarmentSystem

Thisisessentiallythetraditionalmethodofproductionwhereoneoperatorassemblestheentiregarment.Intailoringshopsandinsomecouture,itiscommonforatailortoperformnearlyeveryoperationrequiredtomakethegarment,includingmachining,handworkandpressing.

Withthisproductionsystemtheoperatorwouldbegivenabundleofcutworkandwouldproceedtosewitaccordingtohisorherownmethodofwork.Essentially,thelabourrequiredbythissystemmustbehighlyskilledandversatile,acombinationwhichisbecomingexceedinglyrareandincreasinglyexpensive.Thistypeofsystemiseffectivewhenaverylargevarietyofgarmentshavetobeproducedinextremelysmallquantities.Atypicalapplicationwouldbeinthesewingroomofaboutique,whichproducesitsownmerchandise.

AdvantagesHighlyflexibleforfashionchangesRequiredlittleorganizationRequiredlittlesupervisionJobsatisfactionQuickthroughputtimeLowworkinprogressAbsenteeismnotaproblemDisadvantages

Requiredveryskilledandexperienceoperatorsandlotsoftraining.Inefficientworkersworktosuitthemselves.

Littleuseofworkaids.Productivityislowduetolackofspecializationofoperationandequipment.Costsareexcessive.Lowoperatorperformanceduetovarietyofoperationshandledindividually

WholeGarmentProductionSystemTherearetwotypesofWholeGarmentProductionSystems,CompletewholegarmentandDepartmentalwholegarment.Inthewholegarmentsystemoneindividualmakestheentiregarmentfromcuttingtheclothtosewingandpressingthegarment.Thegarmentisreadyfordispatchoncetheoperatorcompletesthefinaloperation.Thistypeofsystemisusedinafewplaces,whichareengagedincustom-wholesale.Theyarenormallyhighpricedandexclusivelymadeforaparticularcustomer.Theyarelimitedinnumberanddistribution;normallyabout10-20garmentsaremade.Thedepartmentalwholegarmentsystemisalsousedbycustomwholesalemanufacturersaswellashighpriceorbetterdressmanufacturers.Inthedepartmentalwholegarmentsystemoneindividualdoesalltheworkwiththeequipmentallocatedtoadepartment.Forexample,onepersondoesallthecuttingworkincuttingdepartment,secondpersondoesallthesewingworkinsewingdepartment,andthethirdpersondoesthepressingandpackingwork.Theworkersinthissystemmayusemorethanoneequipmenttocompletetheirrespectivejob.Advantages

1.Thissystemismoreeffectivewhenaverylargevarietyofgarmentshavetobeproducedinextremelysmallquantities.

2.InIndividualpieceratesystemtheoperatorswilldowithfullinvolvement:Tofinishmorepieces,toearnmoremoney.3.Operatorwillbespecializedinhisownworkingarea.4.Asthepaydependsuponthecomplicationoftheoperation,theoperatorwilltrytofinishthecomplicatedoperationalsowithoutanydifficulties.5.TheWorkinProgress(WIP)isreduced,atatimeonecutgarmenttooneoperatorandsotheamountasinventoryisreduced.Disadvantages

1.Highlyskilledlaborersaretobeused,sothecostoflabourishigh.2.Theoperatorismoreconcernedonthenumberofpiecesfinishedratherthanthequalityofwork.

3.Productivityislessduetolackofspecialization.4.Forlongrun/bulkquantityofsamestyleisnoteffectiveinthissystem.

SectionorProcessSystem-GroupSystemThisisadevelopmentofthemakingthroughsystem,withthedifferencethattheoperatorsspecializeinonemajorcomponentandsewitfrombeginningtoend.Forexample,anoperatorspecializinginfrontswouldassemblethefront,setthepockets,etc.andperformalltheoperationsrequiredtofinishthatparticularcomponent.Thesewingroomwouldhaveanumberofsections,eachcontainingversatileoperatorscapableofperformingalltheoperationsrequiredforaspecificcomponent.Thesectionsarebuiltaccordingtotheaveragegarmentproduced,andinclude:

Pre-assembling(thepreparationofsmallparts)Componentmaking(front,Backetc.)Mainassembly(closing,settingcollarsand

sleeves,etc.)PreFinishingWorks(lining,Labelingetc.)Finishingoperations(buttonholes,blind

stitching,etc.)

Allinall,thisisaveryefficientsystemforproducingavarietyofstylesinreasonablequantities.Mostlythisissuitableforlessoperationswithspecifiedorcustomizedmachinesareinuse.Advantages

1.Asthelabourofalllevels,i.e.,semi-skilled,skilled,traineecanbeusedinthissystem,thelabourcostislesscomparedwithindividualsystem.2.Productivityishighercomparedtoindividualsystem,becauseoftheuseofspecialmachineandalltypesoflabour.3.Thissystemisveryefficientforproducingavarietyofstylesinreasonablequantities.4.Automationandspecializationcanbedone.5.Absenteeismandmachinebreakdownproblemswillnotcauseseriousproblems.

Disadvantages

1.Allthelevelsofoperatorsareinvolvedinthework,sothequalityofgarmentshouldbestrictlymaintained.2.Eventhoughproductivityishighstillthehighlyskilledoperatorsarerequiredto

performsimpleoperationwithinthesection.3.GroupofpeopleinvolvedineachsectionandsowerequiremoreWIP,whichincreasestheinventorycost.4.Asthisisnotabundlingsystem,therearemorechancestomixupoflost,shadevariation,sizes,soqualityandproductionwillbeaffected.

ProgressiveBundleSystem-BatchSystemTheprogressivebundlesystem(PBS)ofapparelgarmentsproductiongetsitsnamefromthebundlesofgarmentpartsthataremovedsequentiallyfromoperationtooperation.Thisbundlesystem,oftenreferredtoasthetraditionalgarmentsproductionsystem,hasbeenwidelyusedbygarmentsmanufacturersforseveraldecadesandstillistoday.TheAAMATechnicalAdvisoryCommittee(1993)reportedthat80percentoftheapparelmanufacturersusedthebundlesystemofgarmentsproduction.Theyalsopredictedthatuseofbundlesystemsforgarmentsproductionwoulddecreaseasfirmsseekmoreflexibilityintheirproductionsystems.Bundlessystemofapparelproductionconsistofgarmentpartsneededtocompleteaspecificoperationorgarmentcomponent.Forexample,anoperationbundleforpocketsettingmightincludeshirtfrontsandpocketsthataretobeattachedwithgarments.Bundlesizesmayrangefromtwotoahundredparts.Somefirmsoperatewithastandardbundlesizeofparticulargarments,whileotherfirmsvarybundlesizesaccordingtocuttingorders,fabricshading,sizeofthepiecesinthebundle,andtheoperationthatistobecompleted.Somefirmsuseadozenormultiplesofadozenofgarmentsbecausetheirsalesareindozens.Bundlesofgarmentsareassembledinthecuttingroomwherecutpartsarematchedupwithcorrespondingpartsandbundletickets.Bundlesofcutpartsaretransportedtothesewingroominthegarmentsandgiventothegarmentsoperatorscheduledtocompletethegarmentsproductionoperation.Onegarmentsoperatorisexpectedtoperformthesameoperationonallthepiecesinthebundle,retiethebundle,processcoupon,andsetitasideuntilitispickedupandmovedtothenextoperationofgarmentsproduction.Aprogressivebundlesystemofgarmentsproductionmayrequireahighvolumeofworkinprocesscauseofthenumberofunitsinthebundlesandthelargebufferofbackupthatisneededtoensureacontinuousworkflowforalloperatorsingarments.Theprogressivebundlesystemofgarmentsproductionmaybeusedwithaskillcenterorlinelayoutdependingontheorderthatbundlesareadvancedthroughgarmentsproduction.Eachstylemayhavedifferentprocessingrequirementsandthusdifferentrouting.Routingidentifiesthebasicoperations,sequenceofgarmentsproduction,andtheskillcenterswherethosegarmentsoperationsaretobeperformed.Somegarmentsoperationsarecommontomanystyles,andatthoseoperations,workmaybuildupwaitingtobeprocessed.Theprinciplesofthissystemare:Thevarioussectionsarepositionedaccordingtomain

operationsequence,witheachsectionhavingalayoutaccordingtothesequenceofoperationsrequiredtoproduceaparticularcomponent.

Theamountofmachineryforeachoperationwouldbedeterminedbytheoutputrequired.Aworkstoreispositionedatthestartandendofeverysectionofthesebuffersisusedto

storeworkreceivedfromaprecedingoperation,andtoholdworkcompletedbythatsection.Duetotheseworkstoresorbuffers,eachsectionisnotdirectlydependentonthe

precedingsection,butcanabsorbslightvariationsinoutputviathestocksheldwithinthesection.Theprogressivebundlesystem,whilebeingsomewhatunwieldyinoperationandrequiringlargequantitiesofworkinprogress(WIP),isprobablyoneofthemoststablesystemsasregardsoutput.Unlessthereisseriousabsenteeismorprolongedspecialmachinebreakdowns,mostoftheusualhold-upscanbeabsorbedbecauseoftheamountsofworkinprogress.Balancingandthechangeovertonewstylesarealsosomewhatsimplified,duetotheamountofworkheldinreverse.Whenproperlymanaged,theprogressivebundlesystemisversatileandefficient.

Advantages

1.Laborsofalllevels,i.e.,unskilled,skilled,semi-skilledareinvolvedinthissystemwheretheoperationsarebrokenintosmallsimpleoperation.Hencethecostoflabourisverylow.2.Herethequantityofeachcomponentischeckedduringtheindividualoperationitself,hencemorequalitycontrolispossible.3.Thecomponentsaremovedinbundlesfromoneoperationtonextoperation,sothereislesschanceforconfusionlike,lotmix-up,shadevariation,sizevariation,etc.4.Specializationandrhythmofoperationincreaseproductivity.5.AstheWIPishighinthissystem,thisisstablesystem.Becauseofthebuffer,thebreakdown,absenteeism,balancingofline,changeofstylecanbeeasilymanaged.6.Aneffectiveproductioncontrolsystemandqualitycontrolsystemcanbeimplementedsuchas,Timestudy,methodstudytechniques,Operatortrainingprogram.Useofmaterialhandlingequipment,suchascentertable,chute,conveyor,trolley,bins,etc.7.Bundletrackingispossible,soidentifyingandsolvingtheproblemsbecomeseasy

Thesuccessofabundleproductionsystemofgarmentsmanufacturingmaydependonhowtheproductionsystemissetupandusedinaplant.Thisproductionsystemmayallowbetterutilizationofspecializedgarmentsproductionmachines,asoutputfromonespecialpurposeautomatedgarmentsmachinemaybeabletosupplyseveralgarmentsmachineoperatorsforthenextoperation.Smallbundlesofgarmentsallowfasterthroughputunlesstherearebottlenecksandextensivewaitingbetweenoperations.

Disadvantages1.Balancingthelineisdifficultandthisproblemcansolvedbyanefficientsupervisor.2.Propermaintenanceofequipmentandmachineryisneeded.3.Properplanningrequiresforeachbatchandforeachstyle,whichtakesalotoftime.4.Improperplanningcauseslabourturnover,poorquality,lessproduction,etc.5.IncreaseinWIPineachsectionincreasestheinventorycost.6.Plannedandproperlayoutshouldbemadetomakethesystemeffective,ie,smoothflowofmaterial.7.Varietyofstyles&lessquantityarenoteffectiveinthissystem.8.Shuttleoperatorsandutilityoperatorsneededineverybatchtobalancethelineeffectively.Theprogressivebundlesystemofgarmentsproductionisdrivenbycostefficiencyforindividualgarmentsoperations.Garmentsoperatorsperformthesame

operationonacontinuingbasis,whichallowsthemtoincreasetheirspeedandproductivity.Operatorsofgarmentswhoarecompensatedbypieceratesbecomeextremelyefficientatonegarmentsoperationandmaynotbewillingtolearnanewgarmentsoperationbecauseitreducestheirefficiencyandearnings.Individualoperatorsthatworkinaprogressivebundlesystemofgarmentsproductionareindependentofotheroperatorsandthefinalproduct.Slowprocessing,absenteeism,andequipmentfailuremayalsocausemajorbottleneckswithinthesystem.Largequantitiesofworkinprocessareoftencharacteristicofthistypeofgarmentsproductionsystem.Thismayleadtolongerthroughputtime,poorqualityconcealedbybundlesofgarments,largeinventory,extrahandling,anddifficultyincontrollinginventoryofgarmentsindustry.

Straight-lineor‘Synchro’SystemAsitsnamesuggests,thissystemisbasedonasynchronizedflowofworkthrougheachstageofproducingagarment.Time-synchronizationisthemostimportantfactorofthissystembecausetheflowofworkcannotbesynchronizedifthereareconsiderablevariationsinthestandardtimesallowedforalltheoperationsperformedontheline.Forexample,ifoneoperationhasavalueof1.5minutesSAM,thenalltheotheroperationsinthelinemusthavethesame,oraveryclose,value.Themanipulationrequiredtobalancethestandardtimeforeachoperatorcansometimesleadtoillogicalcombinationsofwholeorpartoperationswhicharenotalwaysconducivetotheoverallefficiencyofindividualoperators.TheSynchrosystembyitsverynatureisrigidandparticularlyvulnerabletoabsenteeismandmachinebreakdowns.Atalltimesreserveoperatorsandmachinesmustbeavailabletofillthegaps.Inaddition,thissystemrequiresasufficientvolumeofthesametypeofgarmenttokeepthelineincontinuousoperation.Advantages

1.It’sveryrigidinnature,&particularlyvulnerabletoabsenteeism&machinebreakdowns2.Linebalanceisveryimportantherelabourorhighskillsarerequired,tomaintainthelinebalance3.theproductivityisveryhigh,becauseofregularpaceofoperations4.workinprogresswillbeveryshort5.layoutisverysimpleasinastraightlineDisadvantages:-1.Thesystemisveryrigid2.Theabsenteeism&breakdownofmachinewillbeseriousissue3.Allthetimereserveoperators&machinesshouldbekeptforthisprocess4.TheSAMshouldmewithintheminimalrange,hencenotsuitableforcomplexgarments.

UnitProductionSystem(UPS)Aunitproductionsystem(UPS)ofgarmentsproductionisatypeoflinelayoutthatusesanoverheadtransportersystemtomovegarmentcomponentsfromworkstationtoworkstationforassembly.Allthepartsforasinglegarmentareadvancedthroughtheproductionlinetogetherbymeansofahangingcarrierthattravelsalonganoverheadconveyor.Theoverheadrailgarmentsproductionsystemconsistsofthemainconveyorandaccumulatingrailsforeachworkstationofgarments.Theoverheadconveyoroperates

muchlikearailroadtrack.Carriersaremovedalongthemainconveyorandswitchedtoanaccumulatingrailattheworkstationwhereanoperationistobeperformed.Atthecompletionofanoperationtheoperatorpressesabutton,andthecarriermovesontothenextoperation.Mostunitproductionsystemsofgarmentsproductionarelinkedtoacomputercontrolcenterthatroutesandtracksproductionandprovidesup-to-the-minutedataformanagementdecisions.Theautomaticcontrolofworkflowsortswork,balancestheline,andreducesclaimsoffavoritisminbundledistributioningarmentsproduction.Electronicdatacollectionprovidespayrollandinventorydata,immediatetrackingofstyles,andcostingandperformancedataforpromptdecisions.Processingbeginsatastagingareainthesewingroomofgarments.Cutpartsforoneunitofasinglestylearegroupedandloadeddirectlyfromthestagingareatoahangingcarrier.Loadingiscarefullyplannedsominimalhandlingisrequiredtodelivergarmentpartsinpreciselytheorderandmannerthattheywillbesewn.Whenpossible,garmentsoperationsarecompletedwithoutremovingthepartsfromthecarrier.Variedsizesandtypesofhangingcarriersareavailablefordifferenttypesofgarmentsproducts.Automatedgarmentshandlingreplacesthetraditionalgarmentsproductionsystemofbundling,tyinganduntying,andmanuallymovinggarmentparts.Unitproductionsystemseliminatemostoftheliftingandturningneededtohandlebundlesandgarmentparts.Theneedforbundleticketsandprocessingoperatorcouponsisalsoeliminatedwhenanintegratedcomputersystemmonitorstheworkofeachgarmentsoperator.Individualbarcodesorelectronicdevicesareembeddedinthecarriersandreadbyabarcodescannerateachworkstationandcontrolpointsingarmentsfactory.Anydatathatareneededforsortingandprocessingsuchasstylenumber,colorshade,andlotcanbeincluded.Integratedgarmentsproductionsystemshaveon-lineterminalslocatedateachworkstationtocollectdataoneachoperation.Eachgarmentoperatormayadvancecompletedunits,rerouteunitsthatneedrepairorprocessingtoadifferentstationofgarments,andchecktheirefficienciesandearnings.Garmentsoperatormaysignalformoreinventoryorcallforasupervisorifassistanceisneeded.Theterminalsateachstationenablescentralcontrolcentertotrackeachunitatanygivenmomentandprovidegarmentsmanagementwithdatatomakeimmediatedecisionsonroutingandscheduling.GarmentsoperatorsoftheUPScontrolcentercandeterminesequencesofordersandcolorstokeepoperatorssuppliedwithworkandtominimizechangeinequipment,operations,andthreadcolors.Aunitgarmentsproductionsystemcancontrolmultipleroutesandsimultaneousproductionofmultiplestyleswithoutrestructuringproductionlinesingarments.Thecontrolcentermayperformroutingandautomaticbalancingofworkflow,whichreducesbottlenecksandworkstoppages.Eachoperatoraswellasthecontrolcenterisabletomonitorindividualworkhistory.Datacanbecollectedontheamountoftimeangarmentsoperatorworks,timespentoneachindividualunit,numberofunitscompleted,theoperatorwhoworkedoneachunit,andthepiecerateearnedforeachunitingarments.Thesystemofgarmentsproductionwillcalculatetheearningsperhour,perday,andtheefficiencyrateofeachgarmentsoperator.Asamechanicalsystemthishasbeeninuseformanyyears,butamajoradvancewasmadein1983whencomputerswerefirstusedtoplan,controlanddirecttheflowofworkthroughthesystem.Theessentialfeaturesofthistypeofsystemare:

1.Theunitofproductionisasinglegarmentandnotbundles.

2.Thegarmentcomponentsareautomaticallytransportedfromworkstationtoworkstationaccordingtoapre-determinedsequence.3.Theworkstationsaresoconstructedthatthecomponentsarepresentedascloseaspossibletotheoperator’slefthandinordertoreducetheamountofmovementrequiredtograspandpositionandcomponenttobesewn.Theoperationalprinciplesare,allthecomponentsforonegarmentareloadedintoacarrierataworkstationspeciallydesignedforthispurpose.Thecarrieritselfisdividedintosections,witheachsectionhavingaquick-releaseclamp,whichpreventsthecomponentsfromfallingoutduringmovementthroughthesystem.Whenabatchofgarmentshasbeenloadedintocarrierstheyarefedpastamechanicalorelectronicdevice,whichrecordsthenumberofthecarrierandaddressesittoitsfirstdestination.Someofthemoreintelligentsystemsaddressthecarrierswithallthedestinationstheywillhavetopassthroughtocompletion.Theloadedcarriersarethenfedontothemainpoweredline,whichcontinuallycirculatesbetweentherowsofmachines.Thismain,orhead,lineisconnectedtoeachworkstationbyjunctions,whichopenautomaticallyiftheworkonacarrierisaddressedtothatparticularstation.Thecarrierisdirectedtotheleftsideoftheoperatorandwaitsitsturnalongwiththeothercarriersinthestation.Whentheoperatorhascompletedworkononecarrier,apushbuttonatthesideofthesewingmachineispressedandthisactuatesamechanism,whichtransportsthecarrierbacktothemainline.Asonecarrierleavesthestation,anotherisautomaticallyfedintotakeitsplace.Whenthecarrierleavesthestationitisrecordedonthedatacollectionsystem,andthenaddressedtoitsnextdestination.

UnitProductionBasicDiagram

UnitProductionSystemrequiressubstantialinvestments,whicharenotalwaysjustifiedbyconventionalpaybackcalculations.Apartfromthemeasurabletangiblebenefits,UPSalsohavemanyintangiblebenefitssuchasamoreorderlyandcontrolledflowofwork,andtheabilityviathecontrolcomputerofsimulatingtheproductionsituationsometimeinadvance.Theseintangiblesaredifficulttomeasure,butinthemselvesmakeaverypositivecontributiontotheoverallviabilityoftheunit.Allthingsconsidered,unitproductionsystemshavemajoradvantagesoveralltheothermanualandthemechanicalsystemsusedforthemassproductionofclothing.Mostimportantly,theyprovideaclothingfactorywiththecapabilitytorespondquicklytoanychanges,whichmightoccur.Inthefastmovingfashionbusiness,thisisessential.Advantages

1.Bundlehandlingcompletelyeliminated.2.Thetimeinvolvedinthepick-upanddisposalisreducedtominimum.3.Outputisautomaticallyrecorded,eliminatestheoperatortoregisterthework.4.Thecomputerizedsystemsautomaticallybalancetheworkbetweenstations.5.Upto40stylescanbeproducedsimultaneouslyononesystem.

Benefitsofaunitgarmentsproductionsystemdependonhowaproductionsystemisusedandtheeffectivenessofmanagement.Throughputtimeinthesewingroomcanbedrasticallyreducedwhencomparedtotheprogressivebundlesystemofgarmentsproductionbecauseworksinprocesslevelsarereduced.Garmentsoperatorproductivityincreases.Directlaborcostsarereducedbecauseofprepositionedpartsinthecarriersandeliminationofbundleprocessing.Indirectlaborcostsmaybereducedbyeliminationofbundlehandlingandrequiringfewersupervisors.Qualityisimprovedbecauseofaccountabilityofallgarmentsoperatorsandimmediatevisibilityofproblemsthatarenolongerconcealedinbundlesforextendedperiodsoftime.Thecentralcontrolsystemingarmentsproductionmakesitpossibletoimmediatelytrackaqualityproblemtotheoperatorthatcompletedtheoperation.Otherbenefitsthatarerealizedareimprovedattendanceandemployeeturnoverandreducedspaceutilization.

Disadvantages1.Unitproductionsystemrequireshighinvestments.2.Thepaybackperiodoftheinvestmenttakeslongtime.3.Properplanningisrequiredtobeeffective.ConsiderationsforinstallingaUPSincludecostsofbuyingequipment,costofinstalling,specializedtrainingfortheproductionsystem,andpreventionofdowntime.Downtimeisapotentialproblemwithanyofthegarmentsproductionsystems,butthelowworkinprocessthatismaintainedmakesUPSespeciallyvulnerable

QuickResponseSewingSystem(JustinTime)Shorterleadtimesimprovequality,reducecostandeliminatenon-value-addedwastewithintheorganizationwhilesimultaneouslyincreasingtheorganization’scompetitivenessandmarketsharebyservingcustomersbetterandfaster.Thetime-basedframeworkofQRMaccommodatesstrategicvariabilitysuchasofferingcustom-engineeredproductswhileeliminatingdysfunctionalvariabilitysuchasreworkandchangingduedates.Forthisreason,companiesmakingproductsinloworvaryingvolumeshaveusedQRMasanalternativeortocomplementotherstrategiessuchasLeanManufacturing,TotalQualityManagement,SixSigmaorKaizen.ThissystemwasfirstdevelopedinJapantoenablequickresponsestobemadetomarketchanges,especiallywhenordersforindividualstyleswereinsmalllots.Eachworkstationisequippedwithtwoorfourmachinesandtheoperatorwilltakethegarmentthroughtherequiredoperations,includingpressing,beforeitistransportedtothenextworkstation.Someofthebasicmachineryisduplicatedindifferentstationsandifthereisabottleneckinonesectiontheoverloadisautomaticallytransportedtootherstationswhereoperatorcapacityisavailable.Allthepartsofonegarmentareloadedintoahangingclampattachedtothetrolleyandintheory,thereshouldonlybeonegarmentateachworkstation.Workistransportedbyacomputercontrolled,overheadtrolleysystemandeachstationhasanindividualcontroller,whichprovidestheoperatorwithinformationonthestylebeingworkedon.Thisinformationcomesfromaninformationcard,whichaccompanies

eachtrolley.AlesssophisticatedversionofQRSusesawheeledtrolley,whichcontainsthecomponentsforonegarmentandispushedalongthefloorfromoperatortooperator.AnotherfeatureofQRSisthatalltheoperator’sworkinastandingpositionsothattheycanmovequicklyfromonemachinetoanotherwithintheirownworkstation.Machineheightsareadjustedaccordinglyandtouchpadsandknee-padscontrolsareusedinsteadofconventionalfootpedals.

Features

Supervision:Freetoworkwiththeoperators.Labour:Ofnecessitytheoperatorsmustbehighlyskilledintheoperationofallthe

differentmachinesinoneworkstation.

Quality:In-processinspectionstationsarebuiltintothelineandtheinspectorisabletoreturnfaultyworkviathesystemtotheoperatorconcerned.Productivity:Thisisveryhighbecausetheoperatorhandlesthegarmentonceonlyfora

numberofoperations,insteadofonceforeachoperation.Throughputtime:Astherearesofewgarmentsonthelinethroughputtimeisextremely

short,whichistheobjectiveofthissystem.Layout:Atypicalunitwouldhaveeightworkstationsarrangesaroundthetransport

system.

QRMrequiresfourfundamentalstructuralchangestotransformacompanyorganizedaroundcost-basedmanagementstrategiestoatime-basedfocus:

FunctionaltoCellular:Functionaldepartmentsmustbedissolved.Intheirplace,QRMcellsbecomethemainorganizationalunit.QRMcellsaremoreflexibleandholisticintheirimplementationcomparedtoothercellconcepts,andcanbeappliedoutsidetheshopfloor

Top-downControltoTeamOwnership:Top-downcontrolofprocessesbymanagersandsupervisorsindepartmentsneedstobetransformedtoadecision-makingstructureinwhichQRMcellsmanagethemselvesandhaveownershipoftheentireprocesswithinthecell

SpecializedWorkerstoaCross-trainedWorkforce:Workersneedtobetrainedtoperformmultipletasks.

Efficiency/UtilizationGoalstoLeadTimeReduction:Tosupportthisnewstructure,companiesmustreplacecost-basedgoalsofefficiencyandutilizationwiththeoverarchinggoalofleadtimereductionThereisnodoubtthatthistypeofsystemisoneofthebestanswerstothegarmentproductionrevolution,whichisbecomingmoreapparenteveryday.Fashionchangesarebecomingmorefrequentandasaconsequenceorderlotsareproportionatelysmaller.Aproductionsystem,whichenableschangeoverstobemadeintheminimumoftimeisideallysuitedtothisnewanddynamicsituation.

ModularProductionSystemAmodulargarmentsproductionsystemisacontained,manageableworkunitthatincludesanempoweredworkteam,equipment,andworktobeexecuted.Modulesfrequentlyoperateasminifactorieswithteamsresponsibleforgroupgoalsandself-management.Thenumberofteamsinaplantvarieswiththesizeandneedsofthefirmandproductlineingarments.Teamscanhaveanichefunctionaslongasthereareordersforthattypeofgarmentsproduct,butthesuccessofthistypeofgarmentsoperationisintheflexibilityofbeingabletoproduceawidevarietyofproductsinsmallquantitiesingarments.Manydifferentnamesarecurrentlyusedtoidentifymodulargarmentsproductionsystems,includingmodulargarmentsmanufacturing,cellulargarmentsmanufacturingunits,compactworkteams,flexibleworkgroups,self-directedworkteams,andToyotaSewingSystem(TSS)ingarments.Thebasicpremiseissimilaramongtheseproductionsystems,althoughtheorganizationandimplementationmayvary.ThemodularsystemwasfirstimplementedatcompanyToyotain1978aspartofJIT,andwasknowninthe1980sintheWestastheToyotaSewingSystem.Mondenin1998gavethissystemaU-turnlayoutandclaimedthatthemainadvantageofthatsystemwasthattheamountproducedcaneasilybearrangedbychangingthenumberofoperatorsworkinginthesystem.Themodularsystemworksontheprincipleofpull-typeproductionsystems,inwhichthejobordercomesfromthelaststeptoprevioussteps.Becauseofthis,theamountofworkinprocessislow,evenworkingwhennoinventoryispossible.

Thenumberofemployeesonateam,usually4to15,varieswiththeproductmix.Ageneralruleofthumbistodeterminetheaveragenumberofoperationsrequiredforastylebeingproducedanddividebythree.Teammemberscross-trainedandinterchangeableamongtaskswithinthegroup.Incentivecompensationisbasedongrouppayandbonusesformeetingteamgoalsforoutputandquality.Individualincentivecompensationisnotappropriateforteam-basedgarmentsproduction.Teamsmaybeusedtoperformalltheoperationsoracertainportionoftheassemblyoperationsdependingontheorganizationofthemoduleandprocessesrequired.Beforeafirmcanestablishamodularproductionsystem,itmustprioritizeitsgoalsandmakedecisionsthatreflecttheneedsofthefirm.Withateam-basedsystemoperatorsaregiventheresponsibilityforoperatingtheirmoduletomeetgoalsforthroughputandquality.Theteamisresponsibleformaintainingasmoothworkflow,meetingproductiongoals,maintainingaspecifiedqualitylevel,andhandlingmotivationalsupportfortheteam.Teammembersdevelopaninterdependencytoimprovetheprocessandaccomplishtheirgoals.Interdependencyistherelationshipamongteammembersthatutilizeseveryone’sstrengthsforthebettermentoftheteam.

WorkflowinmodulargarmentsproductionAModulargarmentsProductionSystemoperatesasaPullSystem,withdemandforworkcomingfromthenextoperatorinlinetoprocessthegarment.Wastageisnormal,andworkflowiscontinuousanddoesnotwaitaheadofeachoperation.Thisincreasesthepotentialsforflexibilityofstylesandquantitiesofproductsthatcanbeproduced.Teamsusuallyoperateas‘Stand-up’or‘Sit-down’units.Amodulemaybedividedintoseveralworkzonesbasedonthesequenceofgarmentsoperationsandthetimerequiredforeachoperation.Aworkzoneconsistsofagroupofsequentialgarmentoperations.Operatorsaretrainedtoperformtheoperationsintheirworkzoneandadjacentoperationsinadjoiningworkzonessotheycanmovefreelyfromoneoperationtoanotherasthegarmentprogresses.WorkflowwithinamodulemaybewithaSingle-piecehand-off,Kanban(asystemtocontrolthelogisticalchainfromaproductionpointofview,andisaninventorycontrolsystem.KanbanwasdevelopedbyTaiichiOhno,anindustrialengineeratToyota,asasystemtoimproveandmaintainahighlevelofproduction.),orBump-back

system.Ifasingle-piecehand-offisused,machinesarearrangedinaverytightconfiguration.Assoonasanoperationiscompletedthepartishandedtothenextoperatorforprocessing.Operationsneedtobewellbalancedasthereisusuallyonlyonegarmentcomponentbetweeneachoperation.Somemodulesmayoperatewithabufferorsmallbundleofuptotenpiecesofworkbetweenoperators.Ifasmallbundleisused,anoperatorwillcompletetheoperationontheentirebundleandcarrythebundletothenextoperation.Anoperatormayfollowacomponentorbundleforasmanyoperationsastheyhavebeentrainedoruntiltheadjacentoperatorisreadytoassumeworkonthebundle.AKanbanusesadesignatedworkspacebetweenoperationstobalancesupplywithdemand.Thedesignatedspacewillholdalimitednumberofcompletedcomponents(twoorthree)inqueueforthenextoperation.Ifthedesignatedspaceisfull,thereisnoneedtoproducemoreuntilitisneededorthespaceempties.Thislimitsbuildupofproductaheadofthenextoperation.Whenthespaceisfulltheoperatorcanassistwithotheroperationsthatmaybeslow.Akanbanboardpreparedforproductionisshownhere.

Thebump-backorTSS(ToyotaSewingSystem)approachwasdevelopedbytheToyotaSewnProductManagementSystemandisprobablythemostwidelyusedtypeofteam-basedmanufacturing.Itisastand-upmodulewithflexibleworkzonesandcrosstrainedoperators.Operatorsmaybecross-trainedonuptofourdifferentsuccessiveoperations.Thisenablesoperatorstoshiftfromoperationtooperationuntilthenextoperatorisreadytobeginworkonthegarment.Theoperatorneedingworkstepstothebeginningofthezoneandtakesovertheprocessingatwhateverpointitisintheproductionprocess.Theoperatorwhohasbeenrelievedofthegarmentwillthenmovebacktothebeginningoftheworkzoneandtakeoverworkonanothergarment.Thisapproachenablescontinuousworkonagarmentandallowseachoperatortoperformseveraldifferentoperations.Thisarrangementfrequentlyusesa4-to-lratioofmachinestooperators.

AdvantagesHighflexibility

FastthroughputtimesLowwastagesReducedAbsenteeismReducedRepetitiveMotionAilmentsIncreasedemployeeownershipoftheproductionprocessEmpoweredemployeesImprovedQualityDisadvantages

Ahighcapitalinvestmentinequipment.Highinvestmentininitialtraining.Highcostincurredincontinuedtraining

Anyproductionsystemhasfourprimaryfactors,whichmakeupthesystem.ProcessingTime+TransportationTime+TemporaryStorageTime+InspectionTime=TotalProductionTime.Processingtimeissumtotalofworkingtimeofalloperationsinvolvedinmanufactureofagarment.Transportationtimeinvolvesthetimetakentotransportsemi-finishedorfinishedgarmentsfromonedepartmenttoanotherorfromoneoperation/machinetoanother.Temporarystoragetimeistimeduringwhichthegarment/bundleisidleasitwaitsfornextoperationorforcompletionofcertainparts.Inspectiontimeistimetakenforinspectingsemi-finishedgarmentsforanydefectsduringmanufacturingorinspectingfullyfinishedgarmentsbeforepacking.Themainaimofanyproductionsystemistoachieveminimumpossibletotalproductiontime.Thisautomaticallyreducesin-processinventoryanditscost.Thesub-assemblysystemreducestemporarystoragetimetozerobycombiningtemporarystoragetimewithtransportationtime.Hence,whileconsideringalltheseaspectstheproductionsystem,layout,materialflowetc.willcloselyrelatedtotheproduct,skilllevelofworkers,frequencyofstylechangeetc.hastobeincludedwhiledecidingthesystem.Somepossiblecommonlayoutoptionsareillustratedbelowforreference.

CombinationsofGarmentsProductionSystemsSomefirmsmayusetheprogressivebundlesystemforproducingsmallpartscombinedwithmodularproductionforgarmentassembly.Thisreducestheinvestmentinspecializedequipmentandreducestheteamsizeneeded.Someindustryconsultantsbelievethatamodularsystemcombinedwithaunitproductionsystemprovidesthemostflexibility,fastestthroughput,andmostconsistentquality.Thiswouldbeparticularlyusefulforlargeitemssuchascoverallsorheavycoats.TheUPSwouldmovethegarmentinsteadoftheoperators.Eachmanufacturerneedstodeterminewhatisbestforitsproductlineandproductionrequirements.

Capacity,utilization,required,loadetc.

4CapacityPlanning

Capacityplanningistheprocessofdeterminingtheproductioncapacityneededbyanorganizationtomeetchangingdemandsforitsproducts.Inthecontextofcapacityplanning,designcapacityisthemaximumamountofworkthatanorganizationiscapableofcompletinginagivenperiod.Effectivecapacityisthemaximumamountofworkthatanorganizationiscapableofcompletinginagivenperiodduetoconstraintssuchasqualityproblems,delays,materialhandling,etc.Adiscrepancybetweenthecapacityofanorganizationandthedemandsofitscustomersresultsininefficiency,eitherinunder-utilizedresourcesorunfulfilledcustomers.Thegoalofcapacityplanningistominimizethisdiscrepancy.Demandforanorganization’scapacityvariesbasedonchangesinproductionoutput,suchasincreasingordecreasingtheproductionquantityofanexistingproduct,orproducingnewproducts.Betterutilizationofexistingcapacitycanbeaccomplishedthroughimprovementsinoverallequipmenteffectiveness(OEE).Capacitycanbeincreasedthroughintroducingnewtechniques,equipmentandmaterials,increasingthenumberofworkersormachines,increasingthenumberofshifts,oracquiringadditionalproductionfacilities.

Capacityistheabilityofasystemspotentialforproducinggoodsordeliveringservicesoveraspecifictimeinterval.Thecapacitydecisionswithinacompanyareveryimportantbecausetheyhelpdeterminethelimitofoutputandprovideamajorinsighttodeterminingoperatingcosts.Basicdecisionsaboutcapacityoftenhavelongtermconsequencesandthischapterexplainstheramificationsofthosechoices.Whenconsideringcapacityplanningwithinacompany,threekeyinputsshouldbeconsidered.Thethreeinputsarethekindofcapacitytobedetermined,howmuchoftheproductswillbeneeded,andwhenwilltheproductbeneeded.

Themostimportantconceptofcapacityplanningistofindamediumbetweenlongtermsupplyandcapabilitiesofanorganizationandthepredictedleveloflongtermdemand.Organizationsalsohavetoplanforactualchangesincapacity,changesinconsumerwantsanddemand,technologyandeventheenvironment.Whenevaluatingalternativesincapacityplanning,managershavetoconsiderqualitativeandquantitativeaspectsofthebusiness.Theseaspectsinvolveeconomicfactors,publicopinions,personalpreferencesofmanagers.Excesscapacityariseswhenactualproductionislessthanwhatisachievableoroptimalforafirm.Thisoftenmeansthatthedemandinthemarketfortheproductisbelowwhatthefirmcouldpotentiallysupplytothemarket.Excesscapacityisinefficientandwillcausemanufacturerstoincurextracostsorlosemarketshare.Capacitycanbebrokendownintwocategories:DesignCapacityandEffectiveCapacity:referstothemaximumdesignedservicecapacityoroutputrate.Effectivecapacityisdesigncapacityminuspersonalandotherallowances.Productandservicefactorseffectcapacitytremendously.Whenselectingameasureofcapacity,itisbesttochooseonethatdoesn’tneedupdating.Whendealingwithmorethanoneproduct,itisbesttomeasurecapacityintermsofeachproduct.

Forexample,thecapacityofafirmistoeitherproduce100Trouseror75Shirts.Thisislessconfusingthanjustsayingthecapacityis100or75.Anothermethodofmeasuring

capacityisbyreferringtotheavailabilityofinputs.Notethatonespecificmeasureofcapacitycan’tbeusedinallsituations;itneedstailoredtothespecificsituationathand.

DeterminantsofEffectiveCapacity

Facilities:-Thesizeandprovisionforexpansionarekeyinthedesignoffacilities.Otherfacilityfactorsincludelocationalfactors(transportationcosts,distancetomarket,laborsupply,andenergysources).Thelayoutoftheworkareacandeterminehowsmoothlyworkcanbeperformed.ProductandServiceFactors:-Themoreuniformtheoutput,themoreopportunitiesthereareforstandardizationofmethodsandmaterials.Thisleadstogreatercapacity.ProcessFactors:-Quantitycapabilityisanimportantdeterminantofcapacity,butsoisoutputquality.Ifthequalitydoesnotmeetstandards,thenoutputratedecreasesbecauseofneedofinspectionandreworkactivities.Processimprovementsthatincreasequalityandproductivitycanresultinincreasedcapacity.Anotherprocessfactortoconsideristhetimeittakestochangeoverequipmentsettingsfordifferentproductsorservices.HumanFactors:thetasksthatareneededincertainjobs,thearrayofactivitiesinvolvedandthetraining,skill,andexperiencerequiredtoperformajoballaffectthepotentialandactualoutput.Employeemotivation,absenteeism,andlaborturnoverallaffecttheoutputrateaswell.PolicyFactors:Managementpolicycanaffectcapacitybyallowingornotallowingcapacityoptionssuchasovertimeorsecondorthirdshifts.OperationalFactors:Schedulingproblemsmayoccurwhenanorganizationhasdifferencesinequipmentcapabilitiesamongdifferentpiecesofequipmentordifferencesinjobrequirements.Otherareasofimpactoneffectivecapacityincludeinventorystockingdecisions,latedeliveries,purchasingrequirements,acceptabilityofpurchasedmaterialsandparts,andqualityinspectionandcontrolprocedures.SupplyChainFactors:Questionsinclude:Whatimpactwillthechangeshaveonsuppliers,warehousing,transportation,anddistributors?Ifcapacitywillbeincreased,willtheseelementsofthesupplychainbeabletohandletheincrease?Ifcapacityistobedecreased,whatimpactwillthelossofbusinesshaveontheseelementsofthesupplychain?ExternalFactors:Minimumqualityandperformancestandardscanrestrictmanagement’soptionsforincreasingandusingcapacity.Inadequateplanningcanbeamajorlimitingdeterminingofeffectivecapacity.

Themostimportantpartsofeffectivecapacityareprocessandhumanfactors.Processfactorsmustbeefficientandmustoperatesmoothly,ifnottherateofoutputwilldramaticallydecrease.Humanfactorsmustbetrainedwellandhaveexperience,theymustbemotivatedandhavealowabsenteeismandlaborturnover.Inresolvingconstraintissues,allpossiblealternativesolutionsmustbeevaluated.ThisispossiblebyusingCVPanalysisandtheBreak-EvenPointformula

StepsintheCapacityPlanningProcess1.Estimatefuturecapacityrequirements2.Evaluateexistingcapacityandfacilitiesandidentifygaps3.Identifyalternativesformeetingrequirements4.Conductfinancialanalysesofeachalternative5.Assesskeyqualitativeissuesforeachalternative6.Selectthealternativetopursuethatwillbebestinthelongterm

7.Implementtheselectedalternative8.MonitorresultsFactoryProductionCapacity:-isderivedfromtheresourcesavailableatthemanufacturingplant.Itiscalculatedsimplybytheamountofmachinesavailableandhoursperdaydeterminedtoworktoberealistic,onehastodeterminetheefficiencyleveloftheoperatorsandincorporatethepercentagetoderiveactualcapacity.Example:ifafactoryhas100machinesandworkinghoursare8hoursperdayand26dayspermonth.Theefficiencylevelofoperatorsisobservedtobeat80%,theproductioncapacityavailabletimepermonthwouldbecalculatedasbelow:

Availablemonthlyproductiontimecapacity:100machinesx480Minx80/100=38400Min/day.38400Minx26days=998400Min/monthor16640hours/month

SpecialMachineProductionCapacity:-Onceplanningproduction,ithastobeknownthatifanyspecialoperationisrequiredwithinthegarmentwhichrequirespecialmachineormachines.Ifso,theoutputcapacityforthosegarmentshavetobebaseduponspecialmachineproduction.Themanagementcanthendecideifthosemachinesbeworkedovertimeorifrequiredtomeetshipmentdate,additionalmachinesbepurchased.ForExample,Tocalculatespecialmachinecapacitypermonth,theavailablemachinesare10,workhours/dayare8hours,efficiencylevelis80%andworkingdayspermonthis26days.Specialproductioncapacityintime/month=10machinesx480Minx80/100

=3840Min/day3840Minx26days=99840Min/monthor1664hours/month.MaximumCapacity:Totalhoursavailableundernormalconditionsinagivenperiodoftime.PotentialCapacity:Maximumcapacityadjustedforefficiency.CommittedCapacity:Totalhourspreviouslyallocatedforproductionduringacertaintimeperiod.

AvailableCapacity:Differencebetweenpotentialcapacityandcommittedcapacityforacertaintimeperiod.RequiredCapacity:SamorSAHnecessarytoproduceaspecifiedvolumeinacertaintimeperiodExcessCapacity:Differencebetweenpotentialcapacityandrequiredcapacity.

Forbetterunderstandingofthese,letusworkoutadata.Let’ssayABCGarmentsCompanyhas20operatorswhowork8hoursaday.Theplanthas90%efficiencylevel.Workingshiftis8hoursadayinwhich1hourismainlyforlunchandteatimebreak.So,theirPotentialcapacityfornext10dayswillbe,Potentialproductionhours/day.

PotentialcapacityforadayPotentialcapacityfor10days=20machinesx7hours/day=140hours/day=140hourspdayx90%efficiency=10daysx126hours=1260hourspotentialcapacity.

ASalebringsinorderfor10000unitsofstyle“ax”thatneedstobedeliveredin10days.Theplantalreadyhasacommittedcapacityof600hoursforthe10daysperiod.Itwasestablishedthatstyle“a”hasaproductiontimeof5SAM.Sotheirrequiredcapacityfor10000unitswillbe;

5SAM/unitx10000unitsCapacityrequiredCurrentlyAvailablecapacityAvailablecapacity

=50,000SAMor=50,000/60min=833SAHtocompletetheorder.=potentialcapacity–committedcapacity=1260hours–600hours=660hoursavailable

Letuscheckwithsomeotherdetailsalso,Let’ssayABCGarmentsCompanyhas10operatorswhowork8hoursaday.Theplanthas90%efficiencylevel.Acustomerbringsinorderfor6000unitsofstyle“a”thatneedstobedeliveredin10days.Theplantalreadyhasacommittedcapacityof300hoursforthe10daysperiod.Workingshiftis8hoursadayinwhich1hourismainlyforlunchandteatimebreak.Itwasestablishedthatstyle“a”hasaproductiontimeof5SAM.Theorderof6000unitsrequire30,000SAM(500hours).Whatfactorsshouldbeconsideredindecidingwhethertoaccepttheorderorrefuse?Potentialcapacityofcompanyforthe10workingdays=10machinesx7hours/day=70hoursPotentialproductionhours/day=70hours/dayx90%efficiency=63PPhours/dayPotentialcapacityfor10days=10daysx63hours=630hourspotentialcapacity.Whatisrequiredcapacityforthe6000unitorder?Requiredcapacityforthe6000unitorder=5SAM/unitx6000units=30,000SAMRequiredcapacityinSAH=30,000/60min=500SAHtocompletetheorder.Capacityrequired=500hours.

Whatisavailablecapacityintheplantcurrently?AvailablecapacityAvailablecapacity=potentialcapacity–committedcapacity=630hours–300hours=330hoursavailable

Isavailablecapacityadequatetoaccepttheorder?Ans.330hoursofavailablecapacity–500hoursofrequiredcapacity=170hours

Capacityisnotsufficienttoacceptorderinthesameperiodoftime.Toprocessthesecondorderweneedadditionaltime,ortheshifttimingstobeelevatedasovertimetocovertherequired170hoursorincreasethemachinery.

Aplanningsheethavetobepreparedforeachlineforeffectivemonitoringofthefactory,tofindwhatisavailable,utilizedandbalancecapacityplottedbetter.UtilizationifthetermusedtoMeasureshowmuchoftheavailablecapacityisactuallybeingused,andthisdirectlyrelatedtotheReturnonInvestmentofthefloor.Andtheeffectivenessofthesystem.

ItisnecessarytoidentifythedifferencebetweenthetermsDesignCapacityandActualCapacity.ThedifferencebetweenthesetwoshouldbekeptlowtoobtainmaximumROI,theDesigncapacityisthemaximumoutputrateunderidealconditionsandEffective

capacityisthemaximumoutputrateundernormal(realistic)conditions.

ProcessofCapacityPlanningWhiledoingcapacityplanning,weshouldthinkaboutEffectivecapacity,whichisthemaximumamountofworkthatanorganizationiscapableofcompletinginagivenperiodduetoconstraintssuchasqualityproblems,delays,materialhandling,etc.andthemainobjectkeptinmindistoobtainmaximumeffectivecapacitypossibleoutofthepresentsituation.Duringthevariousprocessstages,afterenvironmentalanalysisweareinapositiontopredicttheavailablecapacity.Wethentrytopreparealternativecapacityplansforourvariouspossiblepredicteddemandsorfuturedemands.Fortheselectionofsuitablecapacityschedule,wewillrunaneconomicanalysistodecide.Prediction:Capacityplansaredependedonthedemandforecastingforoutputs.Itisnotpossibletoestimatethelong-termdemandsandothercontingencieslikeactofgodorelse.Whichmaynotbepredictable.Butasarule,matureproductsaresubjecttobetterpredictionthantherecentlauncheseitherinintroductoryoringrowthstagesofProductLifeCycle(PLC).MultipleOutputs:-foraproducerfactory,therecouldbemanyproductsofdifferentstagesofPLCforwhichdemandistobeforecasted.Inthiscase,thetotaloutputmightnotfluctuateasawhole,butindividualoutputshavingdifferentgrowthratesaffectsdemandfluctuation.Multipleoutputsinsureusagainstsuchuncertainties,especiallydifferentbrandsforeachsegmentresultsinabetterplanningfortotalcapacity.“Demandforecastingforaflexibleoutputiseasierthanthatofaspecificoutputofacontinuousprocessorindustries.Long-termdemandForecasting:-whiledoinglong-termforecastingwemayusethejudgmentalmethodslikeDelphi,Executiveopinionsetc.forthefinalization.Thepasthistorymethodslikemovingaverages,smoothingdataetc.mayalsohelpfuloracasualforecastingmodellikeregressionanalysisandeconometricmodelsarealsousedtodo.Regressionanalysisisaforecastingmodelwhichrelatesthedependentvariablelikesales,pre-productionetc.tooneormoreindependentvariablelikeincome,constructionetc.forexamplethedemandforaweddingsareefornewweddingssolemnizedpreviousyearversusthetrendeffectofincomerangesetc.regressionforecastingisalongandcostlierprocess.Econometricforecastingisfurtherimprovedonregression.Itconsistsofasystemofsimultaneousregression.Forexamplethedemandofsoapisfunctionofitspriceandadvertisingandthepersonaldisposalincomeofthecustomer.Judgmentalmethodsareusedwhenagooddataisnotreadilyavailable.Marketingresearchonconsumerbehavior,product,pricedistributionandresearchverifiesextremelyusefulforlong-termforecasting.Whiledealingwithmultipleoutputs,thedemandforeachisestimatedindependentlyandthensummedup,heterogeneousproductsneedseparateplanningforeachprocessorsubprocess.CapacityPlans–Size:-Tomeetthegrowingdemand,asmalldoe’scapacityisaddedinfrequently.Itcanbeaddedinanticipationofthegrowingrequirementofcanwaittilltherequirementovertakestheavailablecapacities.AlternativeCapacitySources:-itisnotalwaysnecessarytocreateadditionalcapacityforthegrowingrequirements.Wecanutilizethefacilitiesintensively,suchasdoingovertime,doingshitworking(2or3shiftsaday),holidayshiftsetc.togetmoreoutput.Sometimeswecandosub-contracteitherinfullorinpartworkload.Foracompanywithcontinuousprocessitisnotfeasibletohavemoreintensiveusehencesub-contractingmay

beeffective.Ifalternativecapacitysourcesarepossible,wecanreducethecostofcarryingahighcapacity.AlsowehavetodoaCost-Volume(CV)Relationship,analysisbetweenfixedcostsandvariablecosts.EconomicsofSale,highcapacityplanshavehighfixedcostandlowvariablecostperunitcanofferaneconomicsale,LostSalesetc.aretobeplannedandtakencarewhiledoingacapacityplan.Thevariousalternativecapacityplansaretobeevaluatedforconsequencesinfuturewhichisuncertain.Theplanshaveadifferentsetofconstraints.Certaineffectsinfuturearenoteasytoquantify.Henceaquantitativeandqualitativeriskanalysisistobedone.Acapacityplanisaninvestmentproposalthatpaysusormakescashflowoveraperiodoftimeinfuture.Hencethefutureinvestmentsarehoweverdiscountedataparticularratetogettheirpresentvalue.RiskAnalysis:theactualdemandmaybehigherthanthepredictedinsometimes,ifhighertherewillbeundercapacityandiflowertherearisesovercapacityloses.Factorsfavoringovercapacityratherthanundercapacity

1)Buildingcapacityisnotsocostlier2)Buyingoutsideisnotfeasible3)Leadtimetoaddcapacityislong4)Demandrateapproximatestotheoptimisticprediction

5)Lostsalesareviewedverynegativelybytradingcircles,resultinginbiginclineindemand.Factorsfavoringadditionofcapacityonconservativebasis

1)Alternativecapacityplansareeasilyavailable2)Buildupcostofcapacityislow3)Leadtimetobuildnewcapacityisshort4)LostsaleshavenodisastrousresultsSomemaynotbequantified,judgmentistakenastohowtheseaffectthepositionoforganization.

CapacityUtilizationMachineRequirements:Foreveryindustry,asubstantialpartofthefinancialresourcesareinvestedintheplantaremachineandequipment.Thereturnofinvestmentistheonerequiredbyeveryinvestor,andthiscanbemaximizedby

i)Makingtheoptimuminvestmentintheplantandmachines,andii)Makingtheoptimumutilizationoftheinstalledproductioncapacity.

Machinerequirementsdealswiththefirstandlinebalancingisforsecond.Machinecapacityisgenerallyexpressedintermsofmachinehours.Thenumberofmachinesrequiredfortheoperationisexpressedasbelow,

Where,N=NumberofMachinesrequiredfortheoperationST=StandardTimeperJobforoperationinHrs.MP=MaximumProductionrequiredduringthetimeUC=UtilizationofMachinecapacityinpercentage

Forexample,letuscalculatethenumberofmachinesrequiredforajobrequires6minutestodothejob,themaximumquantityrequiredis70,000piecespermonthandthestandardcapacityoftheplantis200hr/monthwithanaverageutilizationofmachine90%.

ST=6Min=6/60Hrs=0.01Hrs===3.89unitsofmachine,Asthemachineisanindivisiblethen4machinesarerequiredfortheordertoprocessintime.LineBalancing.

Alineisdefinedasagroupofoperatorsunderthecontrolofoneproductionsupervisorordoingsamevolumeoftarget.Linebalancingistheequaldistributionofworkamongtheworkersofaparticularline,onthebasisoftimetakenofeachoperation.Linebalancingisavitalkeyintheefficientrunningofaline.Theobjectoftheprocessisto“balancetheworkload”ofeachoperationtomakesurethattheflowofworkissmooth,thatnobottlenecksarecreatedandtheoperatorsareabletoworkatpeakperformancethroughouttheday.Thisprocessisintendedtoreducewaitingtimetoaminimumandtherebyreducingidletime.Orinfact,withtheuseofsomeworkinprogresstoeliminatewaitingtimecompletely.Moredetailsareexplainedinchapter9.

Utilization.

Theavailabletimeisthemaximumhourswecanexpectfromtheworkcenter.However,itisunlikelythiswillbeattainedallthetime.Downtimecanoccurduetomachinebreakdown,absenteeism,lackofmaterial,andallthoseproblemsthatcauseunavoidabledelays.Thepercentageoftimethattheworkcenterisactivecomparedtotheavailabletimeiscalledworkcenterutilization:

Efficiency.

Itispossibleforaworkcentertoutilize100hoursaweekbutnotproduce100standardhoursofwork.Theworkersmightbeworkingatafasterorslowerpacethanthestandardworkingpace,causingtheefficiencyoftheworkcentertobemoreorlessthan100%.

Ratedcapacity.Ratedcapacityiscalculatedbytakingintoaccounttheworkcenterutilizationandefficiency:

Forunderstanding,Aworkcenterconsistsoffourmachinesandisoperatedeighthoursperdayforfivedaysaweek.Historically,theutilizationhasbeen85%andtheefficiency110%.Whatistheratedcapacity?Answer

Availabletime=4x8x5=160hoursperweekRatedcapacity=160x0.85x1.10=149.6standardhoursWeexpecttoget149.6standardhoursofworkfromthatworkcenterinanaverageweek.

DemonstratedCapacityOnewaytofindoutthecapacityofaworkcenteristoexaminethepreviousproductionrecordsandtousethatinformationastheavailablecapacityoftheworkcenter.Demonstratedcapacityistheaveragecapacityachievedoverpastyears.

CapacityRequired(Load)Capacityrequirementsaregeneratedbythepriorityplanningsystemandinvolvetranslatingpriorities,giveninunitsofproductorsomecommonunit,intohoursofworkrequiredateachworkcenterineachtimeperiod.Thistranslationtakesplaceateachofthe

priorityplanninglevelsfromproductionplanningtomasterproductionschedulingtomaterialrequirementsplanning.Figure5.2illustratesthisrelationship.Thelevelofdetail,theplanninghorizon,andthetechniquesusedvarywitheachplanninglevel.Inthistext,wewillstudythematerialrequirementsplanning/capacityrequirementsplanninglevel.Determiningthecapacityrequiredisatwo-stepprocess.First,determinethetimeneededforeachorderateachworkcenter;then,sumupthecapacityrequiredforindividualorderstoobtaintheload.TimeNeededforEachOrderThetimeneededforeachorderisthesumofthesetuptimeandtheruntime.Theruntimeisequaltotheruntimeperpiecemultipliedbythenumberofpiecesintheorder.ExampleProblem.Aworkcenteristoprocess150unitsofgearshaftSG123onworkorder333.Thesetuptimeis1.5hours,andtheruntimeis0.2hoursperpiece.Whatisthestandardtimeneededtoruntheorder?Answer

Totalstandardtime=setuptime+runtime=1.5+(150x0.2)=31.5standardhours

Inthepreviousproblem,howmuchactualtimewillbeneededtoruntheorderiftheworkcenterhasanefficiencyof120%andautilizationof80%?Answer

Capacityrequired=(actualtime)(efficiency)(utilization)Actualtime=Capacityrequired/(efficiencyxutilization)=31.5/(1.2x0.8)=32.8Hr.

LoadTheloadonaworkcenteristhesumoftherequiredtimesforalltheplannedandactualorderstoberunontheworkcenterinaspecifiedperiod.Thestepsincalculatingloadareasfollows:

Determinethestandardhoursofoperationtimeforeachplannedandreleasedorderforeachworkcenterbytimeperiod.Addallthestandardhourstogetherforeachworkcenterineachperiod.Theresultisthetotalrequiredcapacity(load)onthatworkcenterforeachtimeperiodoftheplan.

ExampleProblemAworkcenterhasthefollowingopenordersandplannedordersforweek20,Calculatethetotalstandardtimerequired(load)onthisworkcenterinweek20,Order222isalreadyinprogress,andthereare100remainingtorun.

OrderQuantity

SetupTime(hours)RunTimeTotalTime(hours/piece)(hours)

ReleasedOrders222

333PlannedOrders444555AnswerReleasedOrders222333PlannedOrders444555TotalTime10015001.50.20.2

20030032.50.250.15

Totaltime=0+(100X0.2)Totaltime=1.5+(150x0.2)=20.0standardhours=31.5standardhours

Totaltime=3+(200x0.25)Totaltime=2.5+(300x0.15)=152.0standardhours=53.0standardhours=47.5standardhours

Inweek20,thereisaload(requirement)for152standardhours.Theloadmustnowbecomparedtotheavailablecapacity.Onewayofdoingthisiswithaworkcenterloadreport.

WorkCenterLoadReportTheworkcenterloadreportshowsfuturecapacityrequirementsbasedonreleasedandplannedordersforeachtimeperiodoftheplan.Theloadof152hourscalculatedinthepreviousexampleisforweek20.Similarly,loadsforotherweekscanbecalculatedandrecordedonaloadreportsuchasisshowninFigure5.5.Figure5.6showsthesamedataingraphicalform.Notethatthereportshowsreleasedandplannedload,totalload,ratedcapacityand(over)/undercapacity.Thetermovercapacitymeansthattheworkcenterisoverloadedandthetermundercapacitymeanstheworkcenterisunderloaded.Thistypeofdisplaygivesinformationusedtoadjustavailablecapacityortoadjusttheloadbychangingthepriorityplan.Inthisexample,weeks1and2areoverloaded,thebalanceareunderloaded,andthecumulativeloadislessthantheavailable.Fortheplanner,

WorkCenterLoadReportWeek2021222324TotalReleasedLoad51.545303025181.5PlannedLoad100.512010090100510.5TotalLoad152165130120125692RatedCapacity140140140140140700(Over)/Undercapacity(12)(25)1020158

14012010080

60ReleasedLoadPlannedLoad

402002021222324Week

Thisshowsthereisenoughtotalcapacityovertheplanninghorizon,andavailableCapacityorprioritycanbejuggledtomeettheplan.Therearesoftware’savailableforcapacityplanningandmostoftheplanningsoftwarelikePROSMV,GSDetc.arecomingwithattachedcapacityplanningtools.

Markerplanning,processingfabricfaults,cutorderplanning,fabricreconciliation

5MarkerPlanningandCutting

Materialcostisamajorcomponentofmanufacturingcosts.Ofprimaryimportanceinmanagingmaterialcostistheestablishmentofcontrolovermarkerutilization.Wasteinmarkerscauseseriousfinanciallossesbyreducingtheprofitabilityoftheline.Itiscommonknowledgethatincreasingthenumberofgarmentsasthenumberofsizesinamarkercangivehighermarkerutilization.Itisusefultobreakmarkermakingintotwo.

1)MarkerPlanning,ortheplacementofpatternpiecestomeettechnicalrequirementsandtheneedsofmaterialeconomy2)MarkerUtilization,whichmayincludedrawingthemarkerplandirectlytofabricorontoapapermarkerorcutthefabricdirectlyusinganautocutter.Theoriginaldiagramofalayandmarkerimpliedalargesheetofpaperonwhichweredrawntheedgesofallthepatternpieces,thisisonlyappropriatewhencuttingisdonebymanuallycontrolledknifesandalinemustbeprovidedfortheoperatortofollow.Inearlierdaysmarkerisdrawndirectlytothefabricandlatterprinterpapermakerswereinpractice,bytheyear2005andnowadayscuttingisdonebycomputercontrolledknifesanddrawingpatternshapesareunnecessary.Whereapapermarkerisused,itisnormallystabilizedonthetopplyofthelaybyvariousmeans,thepapermarkeriscutalongwiththefabricplies.ForbetterunderstandingApparelResearchFoundationinUSAsuggestedin1979,thatproductscouldbegroupedintothreebroadcategoriesaccordingtowayofmarkerutilization.

RelativelySimpleProducts:Theseproductsincludestowels,seatcovers,andanyotheritemswithrectangularparts.Inthesecases,themarkerplanningisabletotessellatethepiecestoapproach100%utilization.

ProductswithLargeNumberofSmallParts:-theseproductsincludemen’ssuits,shirtsandsomeblouses.Theyshowasystematicincreaseintheutilization,therearelargenumberofsmallparts,andtheplannerfindsthathavingmoregarmentsmarkeddoesprovidemoreoptionstoexplore.Thebenefitofthesesmallpiecesdoesdiminishaftersomequantityasapracticallimitisreached.

“TheNumberofsizesrequiredtoproducean‘efficient’markerisusuallyoverestimatedbytheapparelindustry”–Trautman1979

ProductswithrelativelyLargePanelsthatfitinmultiplesacrossthewidth:-theseproductsincludemen’sandladiesslacks(chinos,trousersetc.),somedress,sweatshirts,andother‘panel’products.Thelargepanelseffectivelycontrolsthefabricrequirementsandthesmallerpiecesarecutfromthewastegeneratedafterplacingthelargerpieces.

FabricWidthThewidthofthefabricisofgreatimportanceinmarkerplanningtherearethreemainclasscanbeidentified;tubularknittedfabric,narrowopenwidthfabricandwideopenwidthfabric.

TubularKnittedfabric:circularknittingmachinesproducestubesoffabric,whichmayormaynotslitopenwhilefinishing.Iftheyarecutopenthentheycanbegroupedundertheothercategoriesaccordingtoitswidth.Leisurewearandunderwearmanufacturersmakes

extensiveuseoftubularknittedfabric.Thematerialwidthgenerallyisselectedtomatchthewidthofthebodypanel.Sothatthewastecanbeminimized.Anexamplemarkerisshownhere.Heretherepeatisonegarmenthencetheefficiencyislowbutasnearerto75%,butwhileincreasingthegarmentstheefficiencycanbebroughtabove90or

more.

NarrowOpenwidthFabric:afabricwidthofapproximatelyneartoOneMeter(1Meter)aredefinedasnarrow.Constrainttomarkerplanneristhatapproximatelytwobodypiecescanbefittedacrossthewidthofthemarker.Inthiscase,itisusualtopairthesizesandexploitthefactofgradingincrementsasconsistentmovingupordownrange.Hereusuallystartswithanapproximatemiddlesizerange,andanefficientmarkerisprepared.Thenthesizeaboveandbelowthepivotsizesareselectedandanothermarkerispreparedkeepingthepiecesinthesamegeneralposition.Intheidealcase,theadditionalspaceoccupiedbythelargerpiecesisreleasedbythecorrespondingreductionsinthesmallerpieces.Inthisway,aseriesoftwo-sizemarkersarepreparedfortherange.

Thesepairedmarkersarepopularlyknownas‘marriedlays’.Onceamarkerforthepivotsizeisprepared,theremainingmarkerscanbedrawnveryquickly.Thesituationworkswellaslongasthemarkedsizesarerequiredinequalquantities.Ifthisisnotthecase,additionalmarkersmustbemadewithuncertainimplicationsforreductioninwaste.

WideOpenWidthFabric:-fabricofnearly150cmormorewidthprovideconsiderablyfewerconstraintsonmarkerplanning.Characteristically,threebodypiecescanbeplacedacrossthewidthandmanyvariationsarepossible.Iftherearesufficientnumberofsmallpieces,markerutilizationcanbeachievedhighrate.Andiftherearefewersmallpiecesandmorelargepiecesutilizationwillbelowaswell.ItisusualtomaketheratioofthesizesmarkedthesameastheratioofthesizesinthePurchaseOrder.Theseotherwaytermedas‘RatioLays’.Theratiolayshavethreebenefits.

1)Thecutworkcomesoffinthecorrectratiooftheorder.(sometimestwoormoremarkersaremadeifthereiscomplexratioinorder)2)Themixingofsizesgivespotentialforimprovedmarkerutilization.3)Onlyveryfewmarkersareneedtoprepareforanorder.

Thistypehasanincreasedworkloadonoperatorsinthesewingpreparatory.Alsoneedmorestoragespaceiftherearemanysizesandifshadesneedtobeseparatedthenthetimeneedtocompleteworkmayincrease.

Sometimes,thewideopenwidthfabricbeencut‘onthefold’.Thefabricwasfoldedinhalfacrossthewidthandthenlayedasequivalenttonarrowwidth.Thismethodisusuallytoprocessasmallbatchoffabricbyallocatingasinglespreaderorcutter.

GrainDirection

Patternpiecesnormallycarryagrainline.Whenpatternpiecesarelayeddownonfabric,itiscommonwithlargepatterns,thegrainlineshouldbeparalleltothelineofthewarpinthewovenfabricofthewalesinaknittedfabric,inbiascutting,whichisoftenusedinlargepatternpiecesaspartofthegarmentdesignthegrainlineswillnormallyat45otothewarp.Howevermaybetheplacementofthepatternonthefabricthegrainlineshouldbedrawnandplacedparalleltothegrainofthefabriconly.Theanglesorplacementofthegrainlineinpatternonlyhavedifferentdirections.Theplacementofthepatternsonthefabricisdependonvariousotherfactors,suchasSymmetryofthefabricetc.

Symmetryandasymmetryfabrics.

Manyfabriccanbeturnedroundthrough180oandretainthesameappearanceandthesetypeoffabricsaredesignatedas‘eitherway’orsymmetricalfabrics.Theyrequireno

specialactiononthepartofthemarkerplanner.Restrictionsaremoreinthecaseof‘oneway–eitherway’orasymmetricalfabrics.Inthiscaseifafabricplyisturnedrounditdoesnotretainthesameappearance,especiallywhenthetwooppositewaysaresewntogether.Therearesomefabricstermedas‘one-wayonly’thisisalsoanasymmetricfabric,fabricssuchascorduroy,largeheadedobjectprintedfabricsetc.areexamplesofonewayonlyfabric,herethepatternscanonlybeplacesaccordingtothenapofthefabriconlyandwecannotalwayslaystrictwiththegrainsmarked.

Eventhoughwhileplanningwefollowasimplerulethatthegrainofonegarmentshouldalwaysbeinonedirection.Thatmeansallpatternsofasinglegarmentwhilesewingshouldbeofsamelayandsamegranflowed.Hencethemarkerplannershouldensurethatthetopendsofthepatternpieces,astheywillbeworninthegarment,allfacethesameway.Forexample,ifaverticalstripedoesnotshowacompletemirrorimagerepeat,therightandleftsidesofagarmentmaybedesignedtobemirrorimagesofeachother.Inthiscasethemarkerisplannedusingahalfsetofpatterns,andtherequiredeffectiscreatedinthespreadingofthefabricconventionally,whichplacespairsofpliesfacetoface.

Two-WayMarker&OneWayMarker

Twowaymarkerhasthepatternsplacedonbothdirections,andonewaymarkerhasallgarmentsplacedinsamedirection.Plannermustspecifythegraindirectionandprepare1-waymarkersforasymmetryfabrics.Sincenoneofthepatternscanbeflippedthrough180o,thenumberofoptionsinthemarkerisreduced,andbyreducingmarkerutilization.Referthedetailsinthefollowingfigure,comparingtwomarkerplansoneispreparedastwowaymarkerandtheotherasonewaymarkerforthesamepatternpieces.

Thetwowaymarkerplanhasutilizationof79.3%andtheonewaymarkerhas74.8%.Therearefewbasicdifferencesbetweenthetwomarkers,buttheadditionalfacilityofreversingcertainpieceshasmadeasignificantdifferenceinmaterialusage.Everypercentageofsavinginamarkerwillgivehugesavinginmaterialcost.Thisimpliesthatone-waymarkerutilizationarelikelytobeless,butneverexceededthosefortwo-waymarkerusingthesamepieces.Howevertheeffectofthefabricmayvarysometime.Itisnotadvisedtoreverencethepiecesalltime,becausethedrapeeffectanddesignfeaturesofthefabricandgarmentmaynotbesame.Hencebeforethemarkerplanning,itismustforaplannertoknowwhatarethetypeoffabric,theireffectrequirementinthefinishedgarmentetc.thenonlyabettermarkerwithbestutilizationisproducible.Forexampletheinneryokecanbereveredforastripeorcheckbutnotpossibletoreversethepiecesofacuffinmosttime,butpossibleifdesignallow.

Thekeypointstonoteare,

Increasednumberofgarmentsmarkedleadtoimprovedmarkerutilization.Widerwidthfabricsreducetheconstraintsonthemarkerplannerandmayimprove

utilization Ratiomarkersreducethenumberofmarkerstoplanandsimplifyproductioncontrolprocedures.

Markerplanningwithstrippedandcheckfabrics.

Placingpatternpiecesonthechecked(Plaids)orstrippedfabricsimposesnumerousproblemsoncuttingroompersonnel’swhich,despitemanyyearsofendeavor,automationhasfailedtosolve.Therearethreemaindifficultieswhichaffectthemarkermakingandspreadingprocedure;

Fabricdimensionsshowvariations:-problemsassociatedwithbowingandskewing,widthwaystripedandplaidsareverygoodatshowingupthesedistortions.Theyalsoshowdimensionalvariationsalongthelengthofthefabric.Distancebetweenpatternrepeatscanbemeasuredeasilytodeterminethemagnitudeoftheproblem.Thedifferencearisewhereverthefabriccanbedistortedduringitsformationandfinishing.

Superimposedpliesmustbematched:-inordertolayuptheseplaidfabrics,itisessentialthattheplaylengthbedeterminedbythepatternandnotbytheabsolutelength.Consequently,tosuperimposesuccessiveplies,areasoffullnessandtightnessmustbeaccommodatedwithinthelay.

Garmentpiecesmustbepositionedaccuratelyinrelationtothefabricpattern:-havinglayedupthefabric,themarkermustbeplacedoverthetopply.However,themarkerismadetofitfabricwithspecificationofpatternrepeatdimensions,andanexactmatchmaynotoccur.Thismeansadjustmentsmustbemademanuallyduringcutting.

Plaidgarmentsaredesignedwithavarietyofmatchingpositions.Somemayneedmatchingonlyintheneckandshoulder,othersmayhavematchingsideseams;somemayberequiredtomatchwhereeverispossible.Eachadditionalmatchingpositionaddstothecomplexityof

processing.

Thereisgreatpotentialforpatternedfabrictoreduceutilizationitishenceanapparelengineerhastostudycarefullybeforeselectingamethod.Theexaminationofdesignsforitsmanufacturabilityisthefirstaspect.Questionsmustbeaskedindetailforthepossiblewastefulincompatibilities.Thekeypointstorememberexplainedwithexamplesare,

Selectionofpatternrepeatdistancestominimizewaste:-thefigure(a)showsthenumberofgarmentpieceplacedonacheckedfabricwith10cmrepeat.Thepredominantstripesfallsonthebuttonlineanddetermineswherethefrontpiecesneedtobeplaced.Henceitisdesirabletoplacethepiecesoneanothersothatproblemofmatchingchecklinesacrossthefrontareminimizedbutgapsbetweenpatternsareprominentandiswaste.Butifwereducethechecksizeto9cmrepeatasinfigure(b)thegapshavegoneandwasteisreduced.Hencetheapparelengineershouldconsultwiththedesigningteamforthepossibilityofreducingthechecksizeto9cm.butalwaysitmaynotbepossiblebutthisiswhyanapparelengineerisalwaystakespartinmerchandisingandsamplingactivitiesforthepracticabilityofdesignsproducingcanbesolvedbeforeiscomestofloor.

Modificationofthelocationofthepredominantstripe:-itisusualtoincludetheselvedgeoftheshirtingmaterialintothefrontpieces.Onstripedandcheckedfabricswithawiderepeatlength,itisimportanttopositionthebuttonlineinrelationtotheselvedge.Thisistoavoidwasteandtogetpropermatching.Thereare

twooptions,oneistoexcludetheselvedgefromcutpieceandsecondistoincludetheselvedgeinsideplacketfolding.Whileweinclude,thewastagecanbereduced.SpreadingtechniqueforStripesandchecks

Alltrialsforspreadingstripedandcheckedmethodsaretimeconsumingandlabourintensive.Insomesituationscuttingindividualpliesmaybethebestsuitablemethod.Spreadingisgenerallypossibleand

makesbetteruse.Thecommonspreadingtechniquesarebasedonlocatingparticularstripesorchecksandsuperimposingpliesinacontrolledmanner.Shortlengthlaysarespreadcommonly.Majortoolsandmethodsusedare,

CheckSpikes:-importantmatchingpointsarelocatedonaspiketoensurethattheyareoverlaidorsuperimposedduringspreading.Theseinexpensivealignmentaidsareusedtoensurethatcriticalpointsarematchedbuttheymayproducelocalizeddistortionsinfabric.

PinningTable:-theyaredesignedtoovercomethedrawbacksofcheckspikeprinciple.Thespreadingtablehasmanyholesthroughwhichpinscanpass.Theoperatorcanmovethepinwheninisnecessary.Eachsuccessiveplyispositionedonthetablewithmatchingpointsonthepins.itisnecessarytoensurethatthepinsprotrudeoutjustabovetheply.Spreadingisgenerallybyhand,butmachinesmayalsobeused.

Folding:-thefabricisfoldedtomatchthestripestocompensateforanybowofskewthatispresent.Thisisgenerallyusedforprocessingrelativelysimplestripedknits.Fromthe

foldedlengthasmalllayispreparedandthencut.Circularknivesanddiecutterhaveareusedwiththinlays.Thistechniqueisveryeffectiveinminimizingboweffectbutnotconvenientforstyleswithmorecomponents.

BlockingOutandRelaying:-themarkerisplannedwithsomerelayingallowancearoundpliestobematchedandthencutintoblocks.Theblocksthoserequirematchingarethenrelayed,oftenusingasmallpinningtable,sothatallthepliesarecorrectlypositionedandthencutnormally.Thismethodisusediftherearerelativelyfewpiecesrequirematching.Thiscanreducespreadingtimeandmakespossibletopreparelongmarkers.Inthismethodthemainfactorstobecalculatedarethematerialcost.Whenthematerialcostistoohighthismethodisnotadvisableespeciallywhenpatternrepeatlengthbecomelonger.

FabricLosesoutsidemarker.

Althoughmostofthefabricusageiscontrolledbythemarker,thelossesoutsidemarkerareextremefromminor.Thereareessentiallossesassociatedwithspreading,suchasendplywaste,endofpiecewasteetc.thelosesoutsidemarkerareclassifiedmainlyasbelow,

DirectlossesEndplylossesEndspiecelossesEdgeLossesSplicinglossesandfabricfaults

IndirectLossesRemnantlossesMarkerplanninglossesTicketlengthlossesetc.

Endofplylosses:-thelimpnessandextensibilityoffabricsandthesortoflimitationofspreadingequipmentnecessitatestherequirementofsomefabricateachendsofeachply.Theselossesaretypicallyfrom2cmateachend(or4cmperlay).Somestablefabricsmaypermitsmallerallowanceandsomeunstablefabricsmayrequiremore.Itisusefultobeawareoftheleveloftheselosses.Withan8mlaytheendsmakeup0.5%ofthetotalusageofmaterialwhilea4mlaytheendwasteincreasesto1.0%.

Theseisatendencyforendwastetobecomeexcessiveonthickerfabrics,itmakeslayingupandcuttingeasierandreducesthewaste.Eachtypeoffabricshouldbecheckedfortheactualendlossesandacompanystandardshouldbemadetocontrolthis.

Endofpiecelosses:-theendsofthefabricmaybeunsuitablebecauseofmarksordistortionscreatedduringfabricfinishingprocesses,butthelengthaffectedshouldbeafewcentimeters.Themostimportantlosscomesbecausethefabriclengthisnotanexactmultipleoftheplylength.Hencewhilespreadingwehavetosplicetothenextpiecetothenearestsplicepointorthepartbyplymustbelaidasideasaremnantandprocessedseparately,butboththemethodsresultinlossoffabric.Tominimizelosswehavetoincreasetheaveragelengthoffabricwhilepurchasing.ifwehave50cmaveragesplicelengthandanaveragefabriclengthis100mthenwearehavingendpiecelossabout0.5%ofthetotal.Althoughendpiecelossescannotbeeliminated,butitcanbecontrolled,andclearproceduresareneededforsplicingandtheprocessingofremnants.Thewastereductionmethodsofmarkerisexplainedlatter.

Edgelosses:itisusualforthewidthofmarkertobekept3cmlessthantheedge-to-edgewidthofthefabriclay.Themarkerissaidtobemadetotheusablewidthofthefabricanditisdependentonthequalityoftheselvedge,consistencyoffabricwidth,andprecisionofedgecontrolduringspreading.Iftheedge-to-edgewidthis100cm,theedgelossisabout3%andiftheedge-to-edgedistanceis150cmthentheedgelossisabout2%.Hencewiderfabricshaveotherbenefitsbesidesimprovedmarkerutilizations.Foranexceptionallystablefabric,wehaveevenreducetheedgewidthto2cm.hencewidthvariationsofthefabricmustbecontrolledalongsidetheseallowances.

SplicingLossesandfabricfaults:duringspreadingitmaynecessarytocutoutfabricfaultswhichwouldmaketheproductunsalable.Iffaultarecutoutatlay,itisnecessarytoincludesplicingpositionsintothemarkerplan.Thesplicingpositionsareidentifiedbybeingabletodrawareasonablystraightlinebetweenthepieces.Thismeansthefaultwhichfallsbetweenthetwosplicelinescanbecutout,thecutedgecanbedrawnbacktotheprecedingspliceline,andspreadingcontinued.

Ifthemarkerhasbeenplannedwithoutthesplicepositionsandafaultylengthofmaterialhastobecut,thenlengthfromtheplyendtothefaulthastobelaidasideasaremnant.Spreadingproceedsstartingagainatthelayend.Thedistancebetweensplicingpositionsinfluencethewasteproducedbysplicing,theaveragewastewillbenearlyhalftheaveragedistancebetweensplicelines.Asplicingallowanceismadetoensurethatonlyacompletepanelsarebeingcut.

Thesplicingallowancearemadetoensurethatonlycompletepanelsarecut.Theseareotherwaysafetymarginsforcutting,whichcompensatesforsomefactorslike;difficultyofcuttingthefabricsquaretotheselvedge,uncertaintyaboutapreciseposition,manysplicelinesarefarfromstraightlines,etc.

Remnantlosses:theseareproducedwhen,separatedifferentshadesoffabricpiecesandlayuponlycompleteplies.Allpartlyplylengthsareputtoonesideandcutseparately.Remnantlengtharealsogeneratedwhenshortlengthsofmaterialareleftoveraftercompletionofalay.Shortmarkersaretobemadetoobtainfurtherpiecesfromtheselengths.Theymaybesinglegarmentmarkersifthepiecesarelargeandcanhavemanygarmentmarkerispiecesaresmall.Alsowecanusetheremnantlengthforrecutting.

Forexampleiftheaveragemarkerlengthis10mandtheaveragepiecelengthis100m,theaverageremnantlengthisapproximately5mthus5moutofevery100mi.e.about5%of

totalisgoneasremnantlength.Asthisisasignificantwaste,wecanhaveasteplayatoneendoftheproductionmarker,mayhelptocleartheremnantswiththemainlayitself.

Remnantlengthcanbereducedbyutilizingtwoormoreproductionmarkers.Iftwomarkersavailableoneof10mandanotherof8m,itispossibletoallocateindividualpiecestospecificmarkerssothatthelengthofremnantisminimized.Thisapiecesof97mwouldbeallocatedtothe8mmarkerandpiecesof91canbeallocatedtothe10mmarkerbutthisisonlypossiblewhenbothmarkershavingsignificantlyhigherutilization.

Markerplanninglosses:-itoccurs,whenthecostedmarkerplanisnotusedandthemarkeractuallyusedhasareducedutilization.Therearethreemainreasons

1)Specialmarkersforusewithnarrowfabrics:-itisusualtoreceivesmallerwidthfabricsthanthespecificationusable.Toavoiddowngradingcutpanelsbecausetheycontainselvedges,anewmarkermustbeprepared.Evenifthemarkerutilizationismaintained,theratingoffabricusagemustincreasewiththenewmarkersoalosswillbemadeagainsttheoriginalcostedusage.Ifutilizationreduces,thelossesareevenlarger.Itispossibletodeterminethemateriallossesandtheadditionallaborcostforplanningthenarrowermarker,soabasisexistsforfinancialcompensation.

2)Specialmarkersrespondingtocustomerrequirements:trendsmayrequiresomecertaincoloursandcertainsizes,andgarmentsthatarenotsellingmaybemodifiedinsomewayinanattempttostimulateconsumerinterestandinshortertime,henceshortermarkersarelikelytohavereducedutilizationandwillproducefabriclossesagainstcostedvalues.

3)Specialmarkersduetoproductionpressures:-thesewingroomisthecustomerofcuttingroom,thesewingroomscertaincustomeractivitieslikemachinefailure,maycreateabottleneckinasewingline,Insuchcaseswehavetotransferoperationstemporarilytoanotherline,reducingthroughputonthelinewiththeshort-termissueandincreasingthroughputinanotherlinewithadditionaloperates,insuchconditionsitmaybenecessarytodoadditionalcuttingtomatchthetargets.

Ticketlengthlosses:-insomecasesthesupplierattachesatickettoeachpieceindicatingthelengthforwhichcustomerisbilled.Inmanycasesagrosslengthisrecorded,whichisthedistancebetweentheends,andisalsoanetlengththedifferencebetweenthetwofiguresarisesbecausethesuppliercreditsthepurchaseswithanagreedlengthoffabricforeachstrungfault.Ifthereareerrorsinthegrosslengthmeasurementtheyareunlikelytobeaslossestothepurchaser.Toreducethisapracticeofsamplinginspectionofincomingpiecestocheckthereliabilityoftheirsupplier’smeasurementandmaintaincontroloverthesituationisnecessary.

Processingoffabricfaults

Therearethreegeneralmethodsofdealingwithfabricfaults,whichmaybeemployedreadilyincontemporarycuttingrooms.Itisassumedthatallfaultswhichwouldmakethegarmentunsalableevenasasecond(largeholes,flaws,extremestaining,sewnjointsetc.)wouldbecutoutduringspreading.Thefaultsunderconsiderationherearefaultswhichwouldmaketheperfectgarmentsintoseconds.Themethodsare

1)Toleaveallfaultsaloneanddetectandremovetheresultingsecondsgarmentsatfinalexamination.

2)Toexamineeverycutpieceandrecutanythatarefaulty3)Tocutoutduringspreading

Aftercalculatingtheeconomicinfluenceofboththemethodsandthemosteconomicoptionmayonlydeterminefortheparticularlay.Thecostofprocessingfaultsvaryaccordingtothemethodofproductionselected,

1)MakeThrough–thecostofignoringfaults:costisthelosswhichoccurwhenotherwiseperfectgarmentshavetobedowngradedtosecondsbecauseoffaultsinthefabric.Itisassumedthateachfaultypanelresultsinonefaultygarment.LetP=sellingpriceofperfectgarment($perdoz)

S=Sellingpriceofsecondsgarments($perdoz)N=Numberoffaultsper100mY=Costedlength(m/doz)U=Markerutilization(%)Tofindouttheloss,

2)Sortandrecut:thistechniquerequiresfaultypanelstobeidentifiedandreplaced.Toachievethis,additionalfabricisrequiredtorecutthefaultypieces,andtherearelabourcostforthis.Itisassumedthateachfaultaffectsonepieceinthegarmentonly.Thereareanumberofdifferentvariationsinpractice,dependingonthetechnologyresourcesofcuttingroom.

LetF=Fabriccost($/doz)p=NoofpiecespergarmentR=Labourrate($/SMV)

Thesecalculationsaredirectlabourcostandhereexcludesdepartmentaloverheads.Recutsrequiremorefabricthanisgivenbythecostedlengthabout50%isassumedtherefor,thecostedlengthperdozenrecutgarmentsis1.5Ymeters,andthisisbasedonthecurrentpractices.

Hence,12piecesarecutfrom1.5Ymeters1pieceiscutfromTherefore,

Thelabourcostfor100%examinationofallcutpiecespriortocountingandbundlinghasbeenestimatedat0.5SAMperdozenforaleisurewearfactorywith5piecespergarmentandstandardtimewas2.5minperdozen.Theaveragerecuttingtimehasbeenestimatedas2.6SAMperpiecethen

Hence,

3)CutatLay:thecostisthefabriccutoutofthelay,goingbacktothenearestsplicepoint,andthelabour.Sincemanyofthefaultsarelocalized,thefabriclosscanbeestimatedatapproximatelyhalftheaveragesplicelength.Thiswillnotbetruewithlargerfaultsandifthesplicepositionsarenotclearelydefinedinmarker,butitprovidesmorerealisticestimateoffabriclossthanaveragingthedataobtainedfromavarietyoflays.LetL=metersperfaultcutout=halftheaveragesplicelength(m)

T=averagetimetocutoutafault(STD)Fromworkstudyrecordsanaverageof0.33mforTisbeenobtained,whereitrelatedtohandcuttingpracticesduringthespreadingoftubularfabric.Insomeconditionsitmaybe

lessthan1minormaybemorethan1m.butanaveragepropermethodthestandardtimecanbesetto0.33minforT.hence

Anexamplefortheabovesession,whenthreestyleshavebeenexaminedtofindouttheinformationforcalculatingthecostofdealingwithfaults.Costdatafortheproductionstyles.

LosswhilesellingassecondsCostLengthUtilizationFabriccostNumberofpiecesingarmentLabourrateFaultcutlengthor½ofspliceAveragetimetocutafault1%ofsellingpriceperdoz2%offabriccostperdozPalincapsleeveBoleroDressVelourTop

P-S($/doz)7.0410.1026.75Y(m/doz)6.363.217.16U(%)758585F($/m)2.201.404.81P2510R($/doz)0.0450.0450.045L(m)0.350.300.25T(sm)0.330.330.33

0.300.440.930.280.090.69Ifthecutquantitysetas100pcs,thenthelossesinthreesessionsarecalculatedasbelow.Withdifferentpossibledefectrates,herewehavetakenfrom4to26defectpointsper100m.

Defect%=>LossinMakethroughlossinCutatlayLossinSortandRecut

Defect%=>LossinMakethroughlossinCutatlayLossinSortandRecut

Defect%=>LossinMakethroughlossinCutatlayLossinSortandRecut

Plaincapsleeve0481216202401122344556670203959789811852138557289105BoleroDress0481216202409182837465505111622273211131415161819VelourTop048121620240541091632172713260346910313817220723334454657586

Oncethelossesarepreparedthenitneedtobechartedoutandobservedtherightmethod

bymatchingthedefectrateofthefabrictobecut.PLAINCAPSLEEVE-COSTVARIATIONLossinMakethroughlossinCutatlayLossinSortandRecut14012010080604020

004812162024NUMBEROFDEFECTSPER100M

Thecapsleeveiswithtwopieces,thismeansthatthefabricusageforbothrecuttingandsplicingisconsiderable.Sincethedifferencebetweentheperfectandsecondssellingpricearesmall,thecheapestmethodofdealingwithfaultsistoleavethemaloneandallowthemtogointosecondsgarments.

BOLERODRESS-COSTVARIATIONLossinMakethroughlossinCutatlayLossinSortandRecut6050403020100

04812162024NUMBEROFDEFECTSPER100M

Thebolerodressfabricischeapandforfaultratesabove16per100mthereislittletochoosebetweencuttingsoutfaultsfromthelayandsortingandrecutting.Butthelossratefordefectscutoutatlayandspliceistrendwithlowrateofloss,forlowdefectratesmakethroughmethodmaybeselectedbutthecosteffectiveiscutoutatlay.Butwhenathigherdefectrateabove16itisbettertohavethepracticeofsortandrecutmaybecosteffective.

VELOURTOP-COSTVARIATIONLossinMakethroughlossinCutatlayLossinSortandRecut35030025020015010050

004812162024NUMBEROFDEFECTSPER100M

Thevelourfabricforthetopisexpensiveandthenumberofpiecesinthegarmentisalsomore.Thelosswhilethisgarmentsellsassecondsishighcomparedtosortandrecut.Hencethecheapestmethodissortandrecut.

Inpractice,otherconsiderationsmayinfluencethedecisionaboutwhichwaytodealwiththefabricfaults.Sincetherearemanyparametersaffectingtocostoffabricfaults,itisprobablybettertolookatseveralstylesinproductionandtocomparegraphs.Ageneralpolicycanbedevelopedbylookingvariouscases.

Fabricallowancesaretobecalculatedbeforepurchasingthefabricitself,theequationsmaybeusedtoassesswhetherthefabricallowanceofabout12cmperfaultasagreedbymostsupplierssatisfactorily.ThisfigureisreportedbyWira(1971)andbyRae(1974)

Forexampleallowance,ifgivenonthefabrictocutthevelourtopistheequivalentof$0.66perdozengarmentswhenthefaultrateis16per100m

Thebasicequationswhichestimatethecostofdealingwithfabricfaultsaregivenbelow,WhereP=sellingpriceofperfectgarment($perdoz)S=Sellingpriceofsecondsgarments($perdoz)N=Numberoffaultsper100mY=Costedlength(m/doz)U=Markerutilization(%)F=Fabriccost($/doz)p=NoofpiecespergarmentR=Labourrate($/SMV)L=metersperfaultcutout=halftheaveragesplicelength(m)T=averagetimetocutoutafault(STD)

Make-throughmethodisusedwhenthefabricandgarmentischeap,thenumberoffabricfaultsarerelativelyfew,andthereisademandforseconds.Sortandrecutisusedwhenfabricandgarmentisexpensive,whenthefabriciswide,whenthegarmentisconstructedfrommanypieces,andthenumberoffabricfaultisrelativelyhigh.Cutatlayisusedwhensplicepositionsarefairlyclosetogetherandarealsoclearlydefined.Thisoptionissuitablefornarrowerwidthwovenfabricsandtubularknittedfabrics.MarkerUtilization

Itiswidelyrecognizedthat,shortmarkershavelowutilizationanditispossibletoimproveplansbyincreasingthenumberofgarmentsmarked.Asageneralprinciplelongerlaysallowgreaterscopeformarkerplanningandmayachievehighermarkerutilizations

Noofgarments%ofsavingmarked10224485Replantedmarkerlength1.502.945.76

11.40Saving/garmentSavingsper100mtrgarments(mtr)000.033.000.066.000.0757.50

Thechartaboveisacomparisonbetweenthefabricssavingwhileincreasingthenumberofgarmentsinlay.Clearlyshowstheimprovementinmarkerutilizationcangivesubstantialbenefitsinreducingcuttingroomcost.Itisnecessaryforeveryindustryshouldworkouttheabovecomparisonaccordingtheircompanystandardsandavailabilityofresources.Themarkerefficiencycanbecalculatedusingthebelowformula.

ThisformulaisbeenhighlyutilizedbythecomputersandCADprogramsforcalculatingthemarkerplanefficiency.Whereareinhardplanningmethodlikemanualmarkerpreparations,itisnoteasytocalculatetheareaofallpatternshencethebelowformulacanalsobeused.Inthiscase,wehavetoweighthetotallengthoffabricbeforecutting,andthenweighthecutpatters.

Thereareseveralconstraintswhichmayaffecttheincreaseinwaste,ofreductioninnumberoflaysorotherways,likefabricproperties,clothavailabilityetc.whichwillrestrainusfromthesamecutorderplantobefollowedallthetime,henceforeveryorderitneedtobeplanned.Themajorconstraintsare,

Fabricproperties:fabricmayvaryinthicknessandhardness50pliesofawoolsuitingmaybethickerthana150pliesofpoplin,withdirectimplicationsforthenumberofpliesthatcanbeput.Thedifferencesintheirresistancetocuttingmaybedeceptive.Highresistancetothemovementofacuttingknifecanalsolimitthedepthofthelay.Insomecasesfabricswithhighresistancetocuttingproduceconsiderableheatenergy,whichincreasesthetemperatureofthecuttingblade.Someextremecasesthermoplasticmaterialcanfuseandjoinneighboringpliestogether,reducingthelaydepthwillbethesolutiontoreducesuchissues.

Machineandtabledimensions:layingupmachinesprovideapracticallimitonlaydepthbecausethefeedrollerscanberaisedonlyapredeterminedheightabovethetableonly.Straightknivesareusedforcuttingoutlargerpiecesandfinerpiecesarecutusingabandknifemachine,forwhichblocksarecutusingthestraightknife.

Acuttingtableshouldbelongenoughtocarrythelargestlayslikelytoberequired.Whenworkingouttheappropriatelength,spaceneededforspreadingmachinery,forfabricsweightingforlayingup,forblocksofworkawaitingforbandknifecuttingetc.areneedtobeavailableinthecuttingtable.

MachineSpaceSpreadingareaCuttingspaceBandknife

CutOrderPlanning

Loadandcapacityarethetwovariablesrequiredbytheplannertoquantifyefficient

planningschedule.Loadisthequantityofworkthefactoryisrequiredtodo,measuredinstandardminutesorstandardhours.Theloadisdeterminedbycontractsthathavebeenplacedwiththecompanyandthecoastedworkcontentofthegarmentsinrun.

Load=(contract1sizexworkcontent)+(contract2sizexworkcontent)+…etc.Thecapacityistheamountofworkthefactoryiscapableofdoing,measuredinstandardminutesorhoursperweek.Thecapacityisoftendeterminedfromfactoryrecordsofpreviousperformance,And

Oncethisisknown,thentheproductionscheduleispreparedwhichbalancestheloadandthecapacity.Sincebulkofthelabourforceingarmentindustryisinthesewingroom,thesewingschedulemustbethemasterscheduleandthereferencepointforallotherschedules.Afterthatonlyproductionplanningpersoncanpreparethetargetsforsewing,cuttingandfabricdelivery.

Sewingschedule-isdesignedtosatisfythecontractsplacedbythecustomer

Cuttingschedule:-givestheinputnecessarytoachievethesewingschedule.Thecuttingroomexiststosatisfytheneedsofsewingroom,sothecuttingschedulemustbederivedfromthesewingschedule,andisnotbasedonthecuttingroomcapacity.Fabricdeliveryschedule:-providestheinputnecessarytoachievethestockrequiredtoachievethecuttingschedule.Shouldbeconsideredtheconstraintsandleadtimes,thestocklevelrequiredtobufferagainstunsatisfactoryqualityorlatedeliveryproblems,andaimstominimizethecostofacquisitionandstorage.

Cutorderplantakesthetargetsestablishedbythecuttingscheduleandtranslatesthemtoaloadingplanofsuccessivebatchestothecuttingroom,sothatcuttingproceedsinthemostefficientandcosteffectivemanner.

Letuslearnthoughaworkexample,

Thesewingroomisschedulestoproduce200garmentsaday.Themarkeris9mlong,with6garmentsmarked.A2%oflayinglossesareincludedandthemaximumlaydepthis60plies.Letusprepareacuttingscheduletokeepthesewingroomfed.

Wecandodifferentplans,andweshouldconsideralloptionsbeforemakeafinalplanschedule.PlanAtocutonelayperdayfor200garmentsthen,

Requiredgarmentsforproductionfloorperday=200Lengthoffabricrequiredfor200garments=200x1.53=306mNumberofpliesfor200garments==33.3334Numberoflaysperweek(5dayworking)=5Ifwefollowthispattern,wecannoticethatthelaysareshallowandwastefulincuttinglabour,andwehaveanincreasedlabourcostincutting.Hence,wemayplanfurtheroptions,PlanBtocutall60pliesdeepinacut,here,Numberofgarmentsperlay=60x6=360garmentsFabricrequiredfor360garments=360x1.53=550.8mNumberofcutsrequiredperweek==2.77=3Totalgarmentscutinaweek=3x360=1080

Howeverwenoticethat,thiswillproduce1080garmentsinsteadof1000garmentsinaweekandthis80garmentswillneedtemporarystorageandlatterproperreductionofexcessquantityneedtobemade.PlanCtocut1000garmentsperweekandapproximately3lays.Numberofgarmentsperlay==333.33Numberofpliesperlay==55.56

Itisnotpossibletocutexactly100garmentshere,butwehavetoput56pliesinalaythenwewillcut1008garmentsperweek,whichisslightdifferentthenthenumberofgarments.Inthiscondition,Thefabricrequiredtoput56lay=56x6x1.53=514mLaysperweekis=3TotalCutgarmentsperweek=1008Forbettermorereductioninfabricwaste,letusconsideranotheroption,

CutPliesperlaytotalcutquantityFabricrequired155330504.9256336514.08356336514.0810021533.06

Whileweplanthisway,wecanfurtherreducethefabriclosses,sothatwewillcutnearly1002piecesanduse1533.06meteroffabricinsteadof1542.24meterswhilewedo56pliesineachlaytherebysavingabout9.18meterperweek.Whenweusecheaperfabricsthisisnotseemtobeabigvaluebutwhenwecalculatethissavingforanyearproductionthen9.18metersperweekmeansnearly477metersperyear.Thisisagoodsaving.Thisworkedexampleistoshowyouthereareseveralwaysforplanningtoachievetargetandtheapparelengineertoweighthemeritsofdifferentoptionsandtomakedecisionwhichpromoteefficiencyofaction.Theoptimumbatchsizeiscalledtheeconomicquantity.Thefunctionofcutorderplanningistoauthorizetheissuingandprocessingofeconomiccutquantities.

WidthofFabricMarkerType

NumberofSizes

MarkerUtilizationContractDetails

FabricProperties EssentialLayingLosses

QualityConstraints

EconomicCutQuantity LabourCosts

EquipmentConstraintsMaterialAvailability

SewingRoomNeeds

ProductionRates DeliveryDeadlines

Disruptions

CustomerRequirement

Letusprepareacutplanindetailforanorderquantityof2500piecesinthreedifferentcoloursintheratio1:2:1forRed,BlueandGreen.TheorderhastobepreparedforS,M,L,andXLsizesinasizeratio3:2:1:1thetechnicalparametersare,wecanputonly7garmentsinamarkerandcanonlyput50pliesinalay.Thesewingdepartmenthasaproductioncapacityof315piecesperday.Thecutplancanbedescribesasthebelow,buttheproductionscheduleislittledifferent,andtherearemoreoptionsdescribed,thiscutplanwilljustfeedtherequiredforsewingdepartment.Thesecondplanshownherehasadifferentstructurethatwillcutbufferquantityincuttingstoreforsomeday’sproduction.Forbetterunderstandingcomparethebelowchartsasperyourown.

MarkerNo1

Cutplan1#30211AMarkerSizesCutSpreadingSMLXLColourPlyUnitsTotalREDBLUEGREEN32111Red4531531531532112Red4531563031532113Blue4531594531532114Blue45315126031532115Blue45315157531532116Blue44308188330832117Green45315219831532118Green453152513315

TotalCutQtyRequiredDifference

CutQty63012536301077718359359RequiredQty62512506251071714357357Difference5356422TotalCutQty2513

Letusconsiderthesituations,thisplanisformarkerandcutplan,therecuttingprogramhastobemadewiththischart,thechartshowsthedatesforcuttingwithwhichmarkerandwhichquantityetc.forbetterutilization.

Moremethodscanberevealedincombination,forexamplethecontractdetailsofthefollowingorderare,S:M:Lwithquantities300,600,400theconstraintsonlaydimensionsare,

Maximumlayheight=75pliesMaximumlaylength=5garmentsmarked

Thetheoreticalminimumnumberoflaysrequiredtocutthecontractis,Maximumnumberofgarmentsperlay=5x75=375Numberofgarmentsrequired=300+600+400=1300Hence,theminimumnumberoflays==3.47

Thisgivesapracticalminimumoffourlaystocut.Ifthecontractistobecutallowestcost,thelayneedtobeaslonganddeepaspossible.Consequently,atargetcanbeidentifiedas,

SSSSSLay1-60plies60x5=300SMMMMMLay2-75plies75x5=375MMMMLLLay3-75plies75x3=225M,75x2=150LLLLLLLay4–50plies50x5=250L

Thereareothermethodspossible,butthismethodisalsousedtorecordthecutorder.Whileconsideringthevariousavailableoptionsitisnecessarytocalculatethelabourandmaterialcostrequiredforeachtypeofmethods.Andaftercarefullyanalyzingthosedata,thenselectthemosteconomicalmethodfortheproduction.

Costingacutorderplan–MaterialCost

Costingacutorderplanismostimportant,andthiswillgiveexactdetailsofeconomicimplications,etc.forbetterunderstandingletusworkoutwithpracticaldetails,considerwehaveanorderof1200garmentswiththefollowingdetailsidentified.

Quantity1200SizesABCDERatio12421

SinglegarmentMarkerlength2.02.22.42.52.6Endallowances-3cmperlayMaximumnumberofplies-100Maximumlaylength-10mCostoffabric-$3.0permeterletusworkoutthecostwiththisdata,

TargetQuantitypersize=A,B,C,D,E=120,240,480,240,120Averagefabricconsumption=2.34mtr.Numberofgarmentsinamarker==4.27hencepossibilityis4garmentsonly.

Minimumnumberoflays==3

Since,quantitiesarenotinmultiplesof100’sthreelaysisanimpossibilityconsequentlythetargetmustbeabout4lays.Wecandevelopmanymethodsforthiscutplanoptions,thebestonearefollowedtodofurther.

OrderABCDEAAEELay-160plies120000120BCCDLay-280plies080160800BCCDLay-380plies080160800BCCDLay-480plies080160800

TOTALS1202404802401201200

Thisplanhasutilizedthesimpleratiobetweensizessothatonlyonemarkerneedtobepreparedforlays2to4hence,thetotalnumberofmarkersmadearetwoandthequantityofcuttingformarker1isoneandmarker2isfourtogetthetotalquantitycut.

Calculatingmaterialcostiscalculatedsystematicallyas,calculatethemarkerlength,addontheendswastetoobtaintheplylengths,multiplybynumberofpliestoobtainthelaylengthandfinallyexpressthisascost.

Markerlengthforlay1=(2.0+2.0+2.6+2.6)x=8.740m

Markerlengthforlay2to4=(2.2+2.4+2.4+2.5)x=9.025mPlylengthforlay1=8.740+0.030=8.770mPlylengthforlay2to4=9.055+0.030=9.055mLaylengthforlay1=8.770x60=526.20mLaylengthforlay2to4=9.055x80=724.40mHence,MaterialcostisTotallengthoffabric=526.20+(724.40x3)=2699.40Totalcost=2699.40x3=$8098.20

Thiscalculationisassumedthattheconsumptionofgarmentisincludedthemarkerefficiency,ifseparateefficiencyisincludedadditionsaretobemadewiththefabric.Costingacutorderplan–LabourCostLabourcostisalsoimportantasmaterialcost,aproperplanningshouldbemadewithreducedlabourcost.Forbetterunderstandingwecangowithaworkoutexample.

Quantity1200Sizes3638404244Quantity10015020017575

SinglegarmentMarkerlength2.02.12.22.32.4Weneedsomeotherdetails,asbelow,alltimeareinStandardMinutes

1Garment2garment3garment4garmentSpreadingtime/ply(min)Fabricsaving%MarkerPreparationtime(hr.)FabricCostCuttingTimepergarmentmarkedMaximumcuttingheight0.750.800.850.9002360.50.750.901.0=$4permeter=15minutes=100plies

Maximumnumberofgarments/marker=4Labourcost=$2perhourEndsallowance=4cmperplyFortheeasylearningwewillstartwithacuttingplanmakeuseofthreegarmentsmarker.

44444425plies–cut1Firstwehavetofindoutthematerialrequirement,Markerlength(3x2.4)x97/100=6.984mPlyLength6.984+0.040=7.024mLaylength7.024x25=175.60mMaterialcost175.60x4.00=$702.40

Timeformarking=0.90x60=54.00minutesTimeforspreading=0.85x25=21.25minutesTimeforcutting=15.0x3=45.00minutes

Timeforallrequirements=54.00+21.25+45.00=120.25minutes=2.00HrsLabourcost==$4.01Theabovemethodwhenfollowedforthecutorderplanasfollowsforthecurrentscenario,

Order363840424444383842Lay-160plies150757536404042Lay-280plies100200100

Materialcost,Markerlengthforlay1=(2.4+2.1+2.1+2.3)x94/100=8.366mMarkerlengthforlay2=(2.0+2.2+2.2+2.3)x94/100=8.178mPlylengthforlay1=8.366+0.040=8.406mPlylengthforlay2=8.178+0.040=8.218mLaylengthforlay1=8.406x75=630.45mLaylengthforlay2=8.218x100=821.80mMaterialcostlay1=630.45x4.00=$2521.80Materialcostlay2=821.80x4.00=$3287.20TotalMaterialcost=$5809Labourcost,Timeformarkermaking(lay1to2)=1.00x60Timeforspreading(lay1)Timeforspreadinglay2Timeforcutting(lay1-2)TotaltimerequirementLay1Totaltimerequirementforlay2=0.90x75=0.90x100=15.0x4=60.00minutes=67.50minutes=90.00minutes=60.00minutes

=127.50minutes=2.125Hr.=150.00minutes=2.5Hr.Labourcostforlay1=2.125x2=4.25Labourcostforlay2=2.5x2=5.00Totallabourcost=$9.25Totalmaterialcost=$58020Hence,totalcostforcuttingthecontract=$5818.25

Cuttinginstruction

Cuttinginstructionisthemaindocumentaryoutputofthecutorderplanningprocess.Itisknownbyavarietyofnamesinindustrysuchas,cutorder,cutsheet,laysheetetc.thedocumentappearsinavarietyofformsdependsonthelocalneeds.Butasaminimumrequirementthecuttinginstructionmusthavethefollowinginformation’sasshownintheformbelow.Inamanualmanagementinformationsystem(MIS)theissueandprogressofcuttinginstructionsarerecorded.Itistoassurethatthegarmentsarecutinthecorrectratioofsizesandinotherwayavoidlossofcontrolthisenablesthemanagertoknowwhatworkisinprogress,whataretheoverdueandneedofprocessing,weeklyproductiondataetc.nowadayscomputerizedproductionmanagementsystemsallowthesameinsystemrecordsformonitoring.

CUTTINGINSTRUCTION

StyleNoMarkerLengthMarkerNoCuttingInstructionLayLengthDateIssued

FABRICTOBECUT

FabricSizesQualityMarkerQuantityWidthRequiredColourLayedLAYCheckedbyCut

BundledGARMENTSTOBECUTTotalSignedDETAILSOFPURCHASEDMATERIALSLotnoPieceNo

RackNoLengthIssued(M)KnittedweightNoof

Issued(Kg)PliesRemnantFaultyFabricRemarksLengthLengthTOTALSTotalFabricIssuedNo.offaultsLengthcreditedforRemarksallowedfaultsReturnedFabric(forreissueorforaclaimagainstsupplier)Fabricreconciliation

Theimportanceoffabricreconciliationis,forthelay,comparisonistobemadebetweencostedandactualusageoffabric.Andthevarianceisreportedandrecorded.ThisdocumentplaysanimportantroletoanApparelengineertocalculateandcomparewhattheyhaveplannedtodoandwhatachieved.

Fabricreconciliationisdoneafterthefabricisbeencut.Forthebetterunderstandingletusworkoutwithaproblem.

Ratingoffabricusage=1.53m/garmentFabriccost=$2permForthelay1,actualusage=545mNumberofgarmentscut=360Costedusage=360x1.53=550.8mGaininfabric=550.8–545.0=5.8mSaving=5.8x2=$11.60

Andforlay2,actualusage=463mNumberofgarmentscut=300Costedusage=300x1.53=459mGaininfabric=459–463=-4.0(Less)Loss=4.0x2=$8

Thegreatestbenefitisobtainedwhen,eachstylesaremonitoredseparatelyasthiswaywecanmonitorthelossfromearlystage.Datafromsuccessivelaysarerecordedinreconciliationrecords.Whiletherecordshowssatisfactoryresults,theremayoccasionswhentherecordofclothusagerevealssignificantlossesagainstcostedvalues.Itisnecessarythentotakeactiontocontrolthis.

FABRICRECONCILIATIONRECORD

STYLE#32567RatingofFabric0.55m/gmtWeekEnd19/3/2016FabricCost1.50$perm

LayGarmentsActualCostednumberCutusagemUsagem173480260.5264.0180480265.2264.0192480269.2264.0197240133.6132.0218240132.4132.0235480262.0264.0236480263.7264.0

FabricVarianceMonetaryBenefitsGainLossGainLoss

3.55.25-1.2-1.80-5.2-7.80-1.6-2.40-0.4-0.60

2.03.000.30.455.8-8.48.70-12.60TOTAL-3.9

Methods,procedure,productivity,micromotionstudy,OB,skillmatrix,threadconsumption,losttime,Productionstudy

6WorkStudy

Workisthebasicsourceofourlivelihood.Weregardworkdifferentlyatdifferentpointsoftime.Ourattitudetowardsworkchangesfromtimetotime,andisdifferentfromculturetoculture.Workdesignisastudyandthedesignofaworksysteminanorganizationalcontext.Inaproductionunitworkexistsandsodotheworkproblemsoriginatingatindividualworkstations.Theman–material–machinecombinationisthefocusofanyworkproblem.Thisapartoftheentireorganizationorworksystem.Workdesignissystematicinvestigationofdesiredandpresentworksystemstogetidealworksystemandmethodstoproducetheoptimumresulti.e.theproductivityofthesystem.Worksystemsaretoimproveproductivityandeffectiveness,itgoesbeyondasetoftechniques,sinceitneedcontinuousmonitoring.Theobjectivescouldbeincreasedproductivityandhighereffectiveness.Workstudyisoneofthetechniquesofenhancingproductivity.Workstudyshouldbeappliedproperlywithduesupportfromemployeesandmanagementtoenhanceproductivity.Theworkstudycanbegraphicallyrepresentedas,

WorkStudyMethodStudyWorkMeasurementErganomicsIncentives

Workstudyisdefinedasatechniquethatembracesmethodstudyandworkmeasurementwhichareemployedtoensurethebestpossibleuseofhumanandmaterialresourcesincarryingoutthespecifiedactivity.Themainobjectiveofworkstudyistoimproveproductivityofmen,machineandmaterials.

Methodstudyisthesystematicrecordingandcriticalexaminationofexistingandproposedwaysofdoingaworkastodevelopandapplyeasierormoreeffectivemethodsandtoreducecost.Workmeasurementistheapplicationoftechniquesdesignedtoestablishthetimequalifiedworkertocarryoutaspecifiedjobatadefinedlevelofperformance.

Boththeaboveconcepts,methodstudyandworkmeasurement,arecloselyrelatedeachother.Theformertendtoreducetheworkcontentandthelatterestablishestimestandardsonthebasisofworkcontentasdeterminedbytheformer.Hence,generallymethodstudyprecedesworkmeasurementtimestudyisalsoenablescomparisonofalternativemethods.

BasicWorkStudyProcedureWorkstudyconsistsofbasiceightsteps,someofwhicharecommontobothmethodstudyandworkmeasurement.Thebasicsstepsareexplainedbelow,Toconductmethodstudy,weshouldhaveaconductivehumanrelationsclimate,andothersupportsandcoordination.Workstudyifproperlyapplied,tendstoimproveindustrialrelations.Theremayberesistsfromskilledseniorworkershoweverinalongrunthetechniquebenefitsall.Workstudyistobeconductedbyaproperlyqualifiedpersonwhocanwinconfidenceofboththesupervisorsandtheworkers.Heshouldbeabletodealwithpeople.TheWSresultsaretobeappliedwithtact.Thereisalwaysanimprovementpossibleinaprocess.Methodstudyinvolvesthebreakdownofanoperationintoitscomponentelementsandtheelementsareanalyzed.

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BasicStepMSWSSelect√√Record√√Examine√√Develop√√

5Measure√6Define√7Install√√8Maintain√

AnalyticallymethodstudyinvolvesthebasicprocedureofSelect-Record-examine-develop-installmaintainsequences.Themeritofthebasicprocedureisthat,whateverbethejoboritssize,itcanbeapproachedanddealtwithonacommonpattern.

SELECTthejobtobestudiedbymakingsureitisworthwhilespendingtimetoimproveit.Thereareseveralfactorstobetakenintoconsiderationwhileselectingaworktobestudied.

1)EconomicConsiderations:-iftheeconomicconsiderationsofajobaresmall,thenthereisnoreasontocontinuealonginvestigation.Somequestionstoneedtobeansweredlike–willitpaytobeginamethodstudyofthisjob?,andwillitpaytocontinuestudy?Someprimarychoiceslikebottlenecks,movementofmaterialoverlongdistances,operationsinvolvingrepetitiveworketc.

2)TechnicalConsiderations:-itmustbeclearifthereisenoughtechnicalknowledgetocarryoutthestudysuchassettingsonafusingmachine,etc.

3)Humanreactions:-asmentalandemotionalreactionstoinvestigationsandchangesofmethodsplayabigpartintheprocess.Humanreactionsareimportantfactorstotakeintoconsideration.Allthenecessaryunionsandpersonnelshouldbeinvolvedintheprocess.Ifatanytimeaparticularprocessiscausingconflictleavetheprocessalone.

Costisthebasisfortheselectionofoperations,sectionsordepartmentslikelytobenefitfromthemethodstudy.Thefollowingdefectsinanorganizationindicatewheremethodstudyislikelytobringworthwhilesavings.

a)Pooruseofmaterials,labourormachinecapacity,resultinginhighscrapandreprocessingcosts.b)Badlayoutoroperationsplanning,resultinginunnecessarymovementofmaterialsc)Existenceofbottlenecksd)Inconsistenciesinqualitye)Highfailureofworkf)Excessiveovertimeg)Employees’complaintsabouttheirworkwithoutlogicalreasons.

Thequestioniswhetherachangeislikelytoachievethefollowingresultssufficientlytomakethecostofthestudyworthwhile;

a)Increaseproductionandreducecostb)Maintainitwithlesslabour,materialorequipmentc)Improvequalitywithoutadditionallabourorequipmentd)Improvesafetyconditions

e)Improvestandardsofcleanlinessandhousekeepingf)Reducescrap.Whenallthesemattershavebeenweighedupinthelightoftheeconomicimportanceofataskanditsexpectedlife,ApparelEngineershouldbeabletoselecttheworktobeinvestigated.Itneedtolisttheobjectivesforthestudyinorderofpriority.Bothinselectingobjectivesonthelargescale,andinchoosingtheeconomicallyappropriatemethods,mathematicaltechniqueslike“Operationsresearch”arealsousedalongwithmethodstudy.

RECORDeverydetailaboutthejobevenifitseemstohavenoeffectonthemethod.Sometimesthemostminordetailcanleadtoamethodimprovementfailure.TheASMEsymbols–Therbligs–areusedtorecordthealongwithothermethods.

Theactivitiesselectedfortheinvestigationsmaybevisualizedintheentirely,withaviewtoimprovingthembysubsequentcriticalanalysis.arecordofallthedetailsisimportanttohaveacomparisonbetweenpresentandpreviousmethodsandtheirpro’sandcon’s

RecordingTechniques

Recordingtechniquefallintotwocategoriesdependingonthenatureofthejobandthepurposeforwhichtherecordisrequired.Attimesbothtechniquesareusedtopresentacompleterecord.Theinformationfortherecordingtechniqueisobtainedbythefollowingmethods.

VisualobservationCalculationsPhotographic&videographytechniquesSpecialknowledgeandexpertise.

Therearebasicallytwotypesofrecordsaremade,1.Charts–forprocessandtimerecords2.DiagramsandModels–forpathofmovementandcomparison

TypeofChartsusedare,1)OutlineProcesschart2)Flowprocesschart3)TwohandedProcesschart4)Multipleactivitychart

5)Simultaneousmotioncycle(SIMO)Charts

6)TravelChartsMajortypeofDiagramsandModelsare,1)FlowandStringDiagrams

PrincipaloperationsandinspectionsActivitiesofmen,material,orequipmentActivitiesofaworker’stwohands.Activitiesofamenandormachinesonacommontimescale.

Activitiesofaworker’shands,legsandotherbodymovementsonacommontimescale.Movementsofmaterialsbetweendepartmentsetc.

2)TwoandThreedimensionalmodels3)CyclegraphsandchronocyclegraphsPathofmovementofmen,materialorequipmentLayoutofworkplaceandplantHigh-speedandshortcycleoperations.

Alltheserecordingtechniquesarealreadyexplainedinthechapter1,whateverthetypeofchartordiagramprepared,careshouldbetakentoensuretheinformation’srecordedinitareeasytobeunderstoodandrecognized.

Thereare“MakeReady”and“PutAway”operationswhichdealswiththepreparationofmaterialplantofequipmenttoenablethe“do”operationsor“inspection”tobeperformedandwiththeplacingasideofcleaningupafterthe“do”operationorinspection.

The“DoOperations”aretheactualperformanceofworkonthematerialorworkwithplantandequipment.Caretobetakensothatthefollowingdataareincludedinthechartordiagram.

a)Anadequatedescriptionofalltheactivitiesormovementsinvolvedinthemethodb)Whetherthepresentorproposedmethodisshownintherecord.c)Specificreferencetowheretheactivitiesbeginandend.d)Thetimeanddistancescaleused.e)Explanationofanyabbreviationsorspecialdevicesused.f)Thedateofconstructionofthechartordiagram.

Modelsarealwaysusefulinassistingthedevelopmentofnewlayouts,andasvisualaidstoexplainanddiscussproblemsandproposalswithotherpeopleseasily.Besidesmodelsotheraidsaresuchastemplates,andtranslucentplanningmaterialsarealsoused.

Inthecaseofdetailedinvestigationataworkplacewheretheoperationsmaybeveryshortduration,ofperformedatahighspeedorwhereseveraljobsarebeingcarriedoutsimultaneouslytheobservermaybeunabletodistinguishmovementsaccuratelyenoughforrecordingpurposeinsuchsituationsphotographicorvideographicrecordingmethodsarebestsuit.Therearesomeadvantagesofthismethod.

a)Apermanentrecordofworkbeingstudiedisobtainedb)Arecordcanbereferredtoatanytime,inanyplacebyanynumberofpeoplec)Anexcellentmeansisobtainedfordemonstratingdifferencesinmethods,andwhichisvaluable

aidintrainingnewmethod.d)Reproductionoftheoriginalmethodispossibleatanytimeaftertheimprovedmethodhasbeeninstalled.e)Repeatedstudyofworker’sactivitiescanbemadewithoutdisturbingtheoperatoratfrequentintervals.f)Theexaminationofintermittentworkcanbeprocessedwhentheworkitselfisnotactuallyinprogress.g)Therecordedvideoscanbeprojected/inspectedtoanyrequiredspeedandcanbestoppedat

anyconvenientpointforobservation.h)Theycanberunbackwards,whichsometimesenablesclumsyorbackwardmovementstobemoreeasilydetected.i)Digitalrecordsgivesmoreaccuracythanpencil,paperandwatchtechniquesj)Theyaremoreconvenient,betterthaneyeobservation,andarepositiverecord.

EXAMINEisthestepcomesafterrecord.Criticalexaminationofthefactscollectedandrecordedinsomeform,asexplainedearlier,isneedtosolveproblems.Thebestknownapproachto“examine”isthequestioningtechnique.Whichmeans,eachactivityisexaminedthoughsystematicseriesofquestions.Thereare,Primaryandsecondaryquestions.

Thefirststageistoquestiontheneedforperformance,place,sequence,person,etc.andthesecondstageistoquestionstheanswersofthefirststagesubjecttofurtherquerytodeterminewhetherpossiblealternativesarethere,thebasicaimistomeasureanychanceofimprovementispossibleovertheexistingmethod.

Whatwehavetotakecareisthat,eachactivity,initsturn,issubjectedtothequestions,thekeyactivitiesarequestionedfirstandthenother.Alltheprimaryquestionsareneedtobesatisfiedfirst.Theprimaryquestionsaimatreachingconclusionsonfivecardinalpointssuchas,purpose,place,sequence,personmeans.Oncetheseconclusionshavebeenreachedthenwecangowiththesecondaryquestions.Theobjectiveofsecondaryquestioningistodiscoverallthepossiblealternativesforeachofthefiveprincipalpointsandthenfinally,toreachadecisionastowhichalternativeshouldbeadoptedforoptimumresults.

Alltheconclusionsreachedaftertheprimarystageofquestionsmustbecollectedandrecordedattheendofprimaryexamination.Thennarrowdowntherangeofalternativesthatwillpresentthemselvesforconsideration.SECONDARYQUESTIONS

PRIMARYQUESTIONSPossiblealternativesSelectedalternativesWhatisachieved?Isitnecessary?Why?Whatelsecouldbedone?Whatshouldbedone?Whereisitdone?Whythere?

Whenitisdone?Advantages:Disadvantages:Whythen?

After:Before:

Whodoesit?Advantages:Disadvantages:

WhythatpersonWhereelsecoulditbe?Advantages:DisadvantagesWhereshouldit?

Whenshouldit?Whenelsecoulditbe?Advantages:Disadvantages

Whoelsecoulddoit?Whoshould?

Howisit?Advantages:DisadvantagesWhythatway?Advantages:Disadvantages

Howelsecoulditbe?Howshouldit?

Advantages:DisadvantagesAdvantages:Disadvantages

The10majorfactorsexploredduringoperationanalysis,togetherwithtypicalquestionswhichshouldbeaskedabouteachfactor,areasfollows:

1.Purposeofoperationa.Istheresultaccomplishedbytheoperationnecessary?b.Canthepurposeoftheoperationbeaccomplishedbetterinanyotherway?

2.Designofparta.Canmotionsbeeliminatedbydesignchangeswhichwillnotaffectthefunctioningandotherdesirablecharacteristicsoftheproduct?

b.Isthedesignsatisfactoryforautomatedassembly?3.Completesurveyofalloperationsperformedonparta.Cantheoperationbeinganalyzedbeeliminatedbychangingtheprocedureorthesequenceofoperations?b.Canitbecombinedwithanotheroperation?4.Inspectionrequirementsa.Aretolerance,allowance,finish,andotherrequirementsnecessary?b.Willchangingtherequirementsofapreviousoperationmakethisoperationeasiertoperform?5.Materiala.Isthematerialfurnishedinasuitableconditionforuse?b.Ismaterialutilizedtobestadvantageduringprocessing?6.Materialhandlinga.Whereshouldincomingandoutgoingmaterialbelocatedwithrespecttotheworkstation?b.Canaprogressiveassemblylinebesetup?7.Workplacelayout,setup,andtoolequipmenta.Doestheworkplacelayoutconformtotheprinciplesofmotioneconomy?b.Cantheworkbeheldinthemachinebyothermeanstobetteradvantage?8.Commonpossibilitiesforjobimprovementa.Can‘‘dropdelivery’’beused?b.Canfoot-operatedmechanismsbeusedtofreethehandforotherwork?9.Workingconditionsa.Hassafetyreceiveddueconsideration?b.Arenewworkersproperlyintroducedtotheirsurroundings,andaresufficientinstructionsgiventhem?10.Methoda.Istherepetitivenessofthejobsufficienttojustifymoredetailedmotionstudy?b.Shouldfullautomationbeconsidered?

Asasecondstageofconclusion,whichismostlydependonthetoughnessoftheprimaryquestioningandinitialexamination.Itisnecessarytorecordtheadvantagesanddisadvantagesofallalternativesforbettermethoddevelopment.Theunnecessary

advantagesanddisadvantagesshouldbeexcludedtomaximum.Finallylistoutthelistofalternatives,whichhaveitsownadvantagesanddisadvantagesevaluatedagainsttheintentionoftheinvestigation.Andthenthenextstagestarts.

TheresultswhichthecriticalexaminationtechniquecanachievewillbeinfluencedbytheattitudeofmindoftheApparelEngineer.Thefinalresultwilldependupontheskillwithwhichhehasexaminedtherecordedfacts.Theengineershouldpayattentiontothefollowingpoints.

Examinethefactsastheyare,notastheyappeartobe,oroughttobe.Shouldnotbeinfluencedbypreconceivedideas,whichoftencolourtheinterpretationoffacts.Challengeallaspectsoftheproblemandacceptnoansweruntilprovedcorrect.AvoidanyhastyjudgmentsShouldnotignorethesmallerdetails,theyaresometimesjustasimportantasthemajorones.Putasideany“hunches”or“brightideas”untiltheappropriateplacesintheinvestigation.Shouldnotconsidernewmethodsuntiltheundesirablefeaturesoftheexistingmethodhavebeenexposedbysystematicexamining

Bothprimaryandsecondaryquestionsareaskedforeachaspectbeforepassingontothenext.Bythismeansitishoped,

TochallengethefactsofthepresentmethodTodiscoverpossiblealternatives.Todeterminethemostsuitablealternative.

DEVELOPaNewMethodcommencesatthefinalstageofthequestioning,wheretheexaminerwillhavedetermined,

WhatactivitiesarevitaltotheobjectiveWhatistheorderoftheirperformanceWhatactivitiesmightbecombinedUndesirablefeaturesthatshouldbeeliminatedListofalternativesforthekeyactivities,etc.

Thedevelopmentofthenewmethodissimplifiedbyextractingandworkingwiththekeyactivitiesthataresuggestedbytheconclusionsofthecriticalexamination.Thesearetheactivitiesvitaltotheobjective.Withthebackgroundfactorsinmind,alternativesforeachactivityneedtobeselected.Whenalternativesareselectedweneedtoexaminetheirsupportivelinks,whichalsoneedtobeestablished,andaproposedmethodcanbecharted.Thenewchartistobe,

CheckedfordetailsandfurtherimprovementsComparewithanyalternativemethodsdevelopedComparewithpresentmethodtoestimatesavingsBecomepartofthebasisfordefiningthenewmethod.

Oneaspectofevaluationtobedoneatthisstateistotestthevitalfeaturesbyexperimentation.Mistakes,ifany,mustbediscoveredandcorrectedbeforetheydoharm.Itisnecessarytodotrialbeforeinstallingthenewmethod,suchtrialsareto,

Checkeachfeatureispracticableandsafe.Ensurethatqualitystandardsaremet

DiscoverandeliminatedifficultiesandmodifyorincorporateanysuggestionscheckservicesrequiredtooperatesmoothlyCheckassessmentofstaffingandtrainingrequirements.

Whereandhowtheseexperimentsaretobecarriedoutdependsonthefloorconditions.Iftestrunsarecarriedoutinthefloorarea,therearesomedisadvantagesthatcanonlybeoffsetbyqualityofcorporationexistingbetweenthepersonalinvolved.Ifoperatorscanseeandagreewiththeneedfortheimprovementthentheobstaclesareminimized.Butitispreferabletodoatestrunintheadvancedtrainingroomsatfirststagewithanexperttailorandthenimplementonfloor.

INSTALLATIONisthefinalstageandthishasfivestages,

1)Acceptabilityofchangeatthesupervisorylevel2)Acceptanceofthechangeattheworksmanagerslevel3)Acceptabilityofchangeattheworkersunionlevel,insomesituations4)Retentionofworkerstooperatenewsystem5)Continuousmonitoringtoseetheapplicationofnewmethod.

Actuallythestagefivecomesunderthemaintenance.Theremaybecasualchangesduemanyfactorswhichneedtobestudiedcarefullyafterinstallation.

Itisimportanttorealizethatimprovingthemethodisnotsimplyhavinggoodideas.Itisnecessarytomakesurethatyour“improved’methodhasbeenproperlythoughtoutandthatitinfactgivesresultasyouexpected.

Thefinalstageofthebasicprocedureisperhapsthemostdifficultofall.Itisatthispointthatactivesupportisrequiredfrommanagementoperatorsalike.Itisherethatpersonalqualitiesofapparelengineerandhisabilitytoexplainclearlyandsimply,whattheyaretryingtodo,andtheirgiftforgettingalongwithotherpeopleandwinningtheirtrustbecomesofthegreatestimportance.

PreparationsforInstallation

Theinstallationofanewmethodisnotsimpleasitmayappeartobe.Detailedpreparationsmustbemadebeforetheactualinstallationhappens.Onepersononlyshouldhavetheresponsibilityduringtheinstallation.Whilsttheengineerwillbe

responsibleforthetrainingandre-trainingoftheworkers.Hemustmakecertainthatfromthebeginningitself,everyoneunderstandthathecannotgiveexecutivedecisions,andthattheinstructionconcerningtheintroductionandapplicationofthenewmethodmustcomefromthedepartmentmanagerorsupervisortotheworkerinthefirstinstance.

Iftheinstallationistotakeplaceinstages,thenthestagesmustbeselectedtobeconvenientforbothpersonnelandprocess.

Copiesofanytime-tabletocovertheinstallationshouldbebroughtintolinewiththedatesselectedforeachstage.Iftheinstallationislikelytobeaprolongsprocedure,itmaybenecessaryinpreparingthistimetabletoconsider(a)existingworkinprogresslevelsand(b)maintenanceofagoodflowofworkthroughthedepartment

Alllayoutsshouldbecheckedindetailtoensurethatthenecessarymachines,guides,andotherequipmentareavailable.Andthattheservicesarelaidon.Everythingspecialrequiredshouldbeorderedanddeliveredtoin-houseinaccordancewiththetimetable.

PrepareanynewclericalrecordswhicharerequiredSelectandtraintheoperativesasrequired.Carefulselectionandthoroughtrainingisessentialwhere

teamworkisinvolved.Trytoavoidanydifficultieswhichmayarisebetweenthoseselectedforthenewmethod.Andthoseremainontheoldmethod.Providethenecessarytrainingawayfromtheproductionline,preferablyinanindependenttrainingdepartment,ifitispossible.Notifyeveryoneconcernedoftheplansandtimetablefortheinstallation.Onlywhenallthedetailedpreparationshavebeenmadeshouldtheapparelengineerbegintoinstallthenewmethod.Theengineershouldtakeintoconsiderationofthefollowingfactors,Thechangeoverofthemachines,theworkplaceandtherequirementshouldbedoneoutsideworkinghours.Thisistokeepthedisturbanceswillbeminimum

Thefirstfewdaysofoperatingthenewmethodarecritical.Extrasupervisionwillbenecessaryduringtheperiodoftimetoenabletheworkerstolearnthemethodandfollowthemethodonly.Sometimesbysomeexpertisetailorsmaynotacceptthenewmethodunlessuntiltheygotfelteffortsaving.

Anyminormodificationstothenewmethodwhichmustbemadeshouldbecompletedasquicklyaspossible.Ifthereareanyproblemswithanypartofthenewmethod,thereasonsshouldbeestablishedandtheproblemsolved.Asmallreserveoflabourisuseful,eithertoreplaceunsuitablepersonnel,ortoincreasetemporarilythelabourallottedtopartsofthemethod.Thisistoavoidtemporarybottlenecksduethenewmethod

AclosewatchshouldbekeptoftheeffectofthenewmethodonthesupplyofworkTact,encouragementandretrainingarerequiredthroughtheperiodofinstallation.Plentycreditto

theoperatorsshouldbegivenatalltimeforprogressmadeandenthusiasmshouldbeshownateveryopportunitybytheengineer,particularlyifthereisverylittleprogressbeingmadebytheoperatorsatthetime.

Finally,whenthenewmethodisrunningsmoothly,andproduceeffectiveoutputwithincreasedefficiencyandreducedcost,theinstallationcanbeconsideredcompletetemporarily.Therearefiveessentialstepsintheteachingofanewmethod.1)Themindoftheoperatormustbefocuseduponwhatistobelearned

2)Themethodmustbedemonstratedandexplainedwell3)Theoperatormustbeallowedtopractice4)Constantcorrectionoffaults5)OperatormustcontinuethesamemethodOneofthedifficultiesofteachinganewmethodisanoperatorwillusuallyfeelsaferdoingthejobbytheoldmethodandwillshowandunwillingnesstochangeuntil

convincedthatthenewmethodisbetterfromeverypointofview.Tendencyofoperatorsretaintooldhabits.Itisdifficulttoteach“olddognewtricks”somepeoplewillnotacceptmethodchangesanditisthereforeadvisabletotrainnewpeopleinthenewmethodandgivetheotheronesdifferentjobs.Filmsorvideosareparticularlyvaluablewhenre-training,inbreakingoldhabitsitmaybefoundthattheoperatorisquiteunawareofwhatheorsheisdoing.Avideoinslowmotionwillenablethemtoseetheexactmovements,andoncetheyknow,theycanstarttolearnthenewmethod.Apparentlytheoperatorswillbemoreinterestedinthenewmethodiftheyfeeltheyhaveplayedsomepartinitsdevelopment.Theapparelengineershoulddiscusstheoriginalmethodwiththeoperatorsthatwillbeinvestigatedandencouragethemtomakesuggestionsforitsdevelopment.Thesuggestionsmayormaynotbeofmuchvalue,butiftheyarelistenedtoandpossiblyusedinsomeform,theinterestoftheoperatorintheimprovementisstimulated.Inlearninganewseriesofmovements,theoperatorgathersspedandreducesthetimerequiredtoperformthemveryquicklyatfirst,buttherateofimprovementsoonbeginstoslowup,anditrequiredlongpracticetoachievereallyhighandconstantspeed.Itshouldbevaluedthatconcentrationlevelrequiredbytheoperatorwillincreasefatigue.Thissituationrapidlyalters,however,andoncetheoperatorhasbeguntograspthenewmethodandpickupspeed,restperiodscanbemuchshorter.

Onceweknowthecorrecttimefordoingajob,andwehaveestablishedagoodwayofdoingit,wecanusethisinformationforallsortofthingslike,

Costing,Pre-productionplanning,LinebalancingandworkerallocationsandTargetsettingDevelopmentofincentivesystemsandschemesInvestmentappraisalOperatormonitoringOperatortrainingetc.

ProductivityProductivityistheratioofoutputtoinputandisnormallyrepresentedinthefollowingformula

Outputrefersthegoodorservicesproduced,Inputreferstoallresourcesusedinproducingtheoutputthisincludes,Landandbuildings,materials,machinesandpeople.Theuseofwhichismadeofalltheseresourcescombined,determinestheproductivityoftheenterprise.Itisnecessarytoensurethatthebestuseofallresourcestogetthebetterproductivity.Thiscanbeachievedbycoordinatingtheeffortstoeveryoneintheorganizationtoachievethebestresultsandtousetheresourcesaseffectivelyaspossible.

Higherproductivitycancontributetohigherstandardoflivingandwillalsoprovide,LargersuppliesofconsumergoodsandcapitalgoodsatlowercostandlowerpricewithhighqualityHigherrateofrealearningsImprovementinworkingandlivingconditionsincludingshorterhoursofworkAstrengtheningofeconomicfoundationsonwhichthewellbeingofindividualsisbased

Toachieveimprovementorincreaseinproductivityacountryshouldhavebalancedprogramsforeconomicdevelopment.Theyneedtotakestepstomaintainemployment.Theyhavetocreateopportunitiesforemploymentforthosewhoareunemployedofunderemployedorthosewhobecomeunemployedasaresultofproductivityimprovements.Eventhoughthegeneralrequirementsarerelatedtocountryplanningbutthemainresponsibilityforraisingproductivitystillrestswiththemanagementofcompanies,becausetheyhavetheabilityandresourcesattheirdisposal,toimplementandcreatefavoriteconditionsforthis.Thisobviouslyrequirescooperationfromtheworkersandtradeunionscanencourageworkerswhentheyaresatisfiedthattheproductivityimprovementprogrambenefitstheworkersaswellasthecompanyandhencethecountry.ItisimportanttodistinguishbetweenProductionandProductivity.Althoughproductionmaybeincreaseditisnotnecessarythatproductivitywillhaveincreased.Letusconsidertheexamplebelow,Thefactory1producing500dressperdaywith50operatorsandfactory2producing675dressperdaywith75operators.Whenweseetheproductionfactory2hashigherproductionperdaybutwhenweconsidertheproductivityratiothefactoryonehas10:1andfactory2has9:1meansoneoperatorisproducing10garmentsperdayinfactory1while9garmentsinfactory2.Hence,factory1ismoreproductivethanfactory2.TheeffectiveuseofmaximumproductivityofLandBuildingsisanimportantsourceofcostreduction,especiallywhenanenterpriseisexpandingandneedsincreasedworkingspace.Thisisachievedwitherbyhigherproductionfromexistinglandandbuildingsorbyobtainingthesameproductionfromasmallerareaoflandandbuilding.Toobtainhigherproductivityfrommachineofpeople,itisnecessarytothinkintermsofTIME,sinceitistheoutputofgoodproductionfromamachineorfromaworker.Productivityofaworkerormachineisexpressedasthe“outputperman-hourormachinehour”whereamanhouristhelabourofonepersonforonehourandamachinehouristherunningofamachineforonehour.Highproductivityofmaterialisachievedbysavinginmaterialsdirectorindirectareachievedinthefollowingway,

-Atthedesignstageortimeofpreparationofworkspecification-Byensuringthatthedesignissuchthatthegarmentcanbemanufacturedwiththeleastpossibleuseoffabricandtrims,especiallywhentheyarescarce(rare)orexpensive-Byensuringthatplantandequipmentspecifiedforpurchaseisthemosteconomicalpossible,intermsofproduction.Forexamplewehavetodoalapfelledseamandwehaveonlyasingleneedleavailablethematerialandlabourusearehighwhereifwecangetadoubleneedlewithlapfellfolderwecansewthesameseamwithoneworkerandatastretchreducingmaterialuseinthreadandlabouruseandincreasedproductionrate.

Highproductivityisachievedwheretheexcessworkcontentandineffectivetimeforajobaresmall,orhavebeeneliminated.Thebasicworkcontentisahighpercentageofthetotaltimeforthejob.Productivityimprovementmaybeachievedinoneofthefollowingways;

IncreaseoutputwithoutincreasinginputMaintainoutputbutdecreasetheinputIncreasetheoutputatthesametimedecreasingtheinputIncreasinginputwithcorrespondinghigherincreaseinoutputDecreasingoutputwithacorrespondinghigherdecreaseininput.

Factorstendingtoreduceproductivity1)Excessworkcontentaddedbydefectsindesignorspecificationofproduct

-Thebaddesignofthegarmentpreventstheuseofthemosteconomicmethodofsewing.-Thelackofstandardizationpreventstheuseofhighspeedproductionprocess-Incorrectqualitystandardscauseunnecessarywork-Thedesignofthegarmentmaymeanthatanexcessiveamountoffabrichastobewastedincutting,duetotheshapeofthepatterparts.-Largesizeoftheragesandcoloursreducethenumberofsizeswhichcanbemarkedin,therebyincreasingtheclothusagepersize.

2)ExcessWorkcontentaddedbyinefficientmethodsofmanufacturingoperation-Theuseofwrongmachinescancausereducedoutput-Ifthemethodisnotbeingadheredto,thenproductivitywillbereduced-Badworkplacelayoutcauseswastedmovement-Anoperator’sbadworkingmethodcauseswastedtimeandeffort.

3)Ineffectivetimeduetoshortcomingsofmanagementorsupervisors

-Excessproductvarietyaddstoidletime,duetoshortruns.-Thelackofstandardizationaddsidletimeduetochangeovers-Designchangesaddineffectivetimeduetostoppagesforre-training-Badplanningoftheworkandordersreducesefficiency-Lackoffabricduetobadplanningcauseswaitingtime-Badlymaintainedmachinescausesidletime-Machinesinbadconditioncausesbadquality-Badworkingconditionspreventtheoperatorfromworkingsteady,feelingcomfortable.-Accidentscauselosttime-Poorserviceoperatorscausedelays,waitingforfabricetc.

4)Ineffectivetimewithinthecontrolofoperator-Absence,latenessandlazinessreduceproductivity-Carelessnessworkmanshipcausesbadquality-Accidentsduetocarelessnesscauseabsenteeism

Thevalueofworkstudy

Investigationsandimprovementsofworkattheworkplaceisnotanewtaskinfactitwashandledbygoodmanagerseversincetheindustrystarts.Howeverduetoshortsupplyofskilledmanagersandincreasingdemandsplacedonthemitisvirtuallyimpossibletodevotesufficienttimeandefforttoinvestigatingandprovidinglongertermsolutions.Themainvalueofworkstudyisthatbycarryingoutitssystematicproceduresitprovidesmanagerswithresultthatarebetterandlongertermthaninthepresent.Duetoitssystematicnaturemoretimeisneededtocarryoutastudyofworkasaresult,itbecomenecessarytoseparatethistaskfromthatofamanager.Unlessallthatfactsareknowitisimpossibletoensurethatanyalterationtocurrentmethodswillbeeffective.Thusitrequiresconstantobservationandstudyandshouldbetheresponsibilityofapersonwhoisnotinvolvedinthedirectmanagementduties.Workstudyisthusaservicetomanagementandsupervisionandwillensurethebenefitsof,

-Itisameansofraisingtheproductiveefficiencyofafactoryororganizationwithlittleor

nocapitalinvestment-Itissystematicandensuresthatnofactorisoverlooked-Itisthemostaccuratemeansofsettingstandardsuponwhichproductionplanningandcontrolcantakeplace-Theresultantsavingsstartatonceandcontinueforaslongastheoperationscontinueintheimprovedform-Itisatoolwhichcanbeappliedeverywhere-Itisoneofthemostpenetratingtoolsofinvestigationavailabletomanagement.Toachievethefullbenefitofworkstudy,itshouldbeappliedinallareasofanorganizationanddonecontinuously.Thefulleffectofworkstudywillonlybefeltinanorganizationwhenallemployeesbecomeaccustomedtoanattitudethatdoesnottolerateinanyform,whethermaterial,timeeffortorhumanability.Therefusaltoacceptwithoutquestioningthatthingsshouldbedoneinacertainwaybecauseitisthewayithasalwaysbeendone.

MicromotionStudies

Twohandedprocesscharts,simocharts,cyclegraphsandchronocyclegraphsareusedforthemicromotionstudyofoperationsattheworkplace.Themostdetailedaspectsofmethodimprovementareconcernedinthisstudies.Micromotionanalysisisexpensivetoconduct,andshouldbeundertaken,ifitappearseconomicallyjustifiable,onlyafterlargescaleimprovementhasbeenfullyinvestigatedasaresultofusingtheotherrecordingtechniques.

Incertaintypeofoperations,particularlythosewithveryshortcycleswhicharerepeatedthousandsoftimes(suchasthepackingofshirtsintoboxesorboxesintocartons)itisvaluabletogoinmuchgreaterdetailedstudiestodeterminewherethemovementsandeffortscanbesavedandtodevelopthebestpossiblepatternofmovementthusenablingtheoperatortoperformtheoperationrepeatedlywithminimumeffortandfatigue.

Thetechniqueusedusuallyvideorecordingarecollectivelycalledasmicromotionstudy.Therearesoftwareusedforanalysisnowadays.Themicromotiontechniquesisbasedontheideaofdividinghumanactivitiesintodivisionsofmovementorgroupsofmovementsaccordingtothepurposeforwhichtheyaremade.Wesometimesdividetotheminimumleveltillthemovementofafingerandtheomissionsmaybeinformofmovementsofaspecificfingerforwhichmaybedevelopinganewtypeofglovestousewhileperformingtheoperationtoavoidmovementofthefingeretc.

Therearemanymethodsusedtodotherecordingoftheoperation,sometimesadirectcameracanbeusedforrecordingoperation,butwhiletheoperatorisawarethatheisbeingrecordedthentheremaybemovementdifferences,itisbettertomakeawaretheoperatoraboutthestudyandmakehimworkwithoutanychangesisbetter.Insomesituationsindirectrecodingmethodslikeoverheadedcameraetc.maybeusedforthepurpose.Micromotionstudyisoneofthemostaccuratetechniqueofworkanalysis.Itmakesuseofmotionpicturesofthedifferentactivitiesormovementssowiththehelpofcamera.Verysmalltimeupto0.0005minutecanbemeasuredandrecordedbythissystem.Themotiontimedatafromthemovietakenistransferredtothesimochart.Thesimochartdatacanbefurtheranalyzedforthepurposeofworkplacelayoutormethodimprovement.ThistechniquewasdevelopedbyFranGilbrethwhoconsideredthatanoperationconsists

ofminuteelementswhichmayberepetitiveornon-repetitive.HetermedtheseelementsasTherblig.Themicromotionstudycanbeused,

-Tostudythenatureandpathofmovementsforobtainingtheelementsofanoperation.-Tostudytheactivitiesofthemachineandtheoperator-Toimparttrainingtotheworkersoroperatorsregardingmotioneconomysothatunnecessary

movementsbytheworkersmaybeavoided.-Tostudytherelationshipbetweentheactivitiesofoperatorandthemachine.-Tokeeppermanentrecordofthemostefficientwayofperformingataskforfuturereference.-Toobtainmotiontimedatafordevelopingsynthetictimestandardsforvariouselements-Forcarryingoutresearchinthefieldofmethodandtimestudy.

OperationBreakdown(OB)

Breakdownisalistingofthecontentofajobbyelements.Agarmentconsistsofsomepartsandsomegroupofoperations.Breakdownmeanstowritingdownallpartsandallprocess/operationafteroneanotherlyingwiththecompletegarmentaccordingtoprocesssequence.ItisamusttowritedowntheestimatedSMVandtypeofmachinebesideeachandeveryprocess.

OperationBreakdownProcedure:

1.Floorsectionleader,teamleadertechnicianandworkstudyofficermustsittogethertomakebreakdown.2.Technicianbreaksthegarmentsintopartsangatheredthepartsoneafteranotherbyoperation/process3.ThenworkstudyofficerandfloorsectionleaderfoxuptheSMVofthoseoperation4.ByproceedingthistechniquewhenallprocesscompletedneedtosummarizeallprocessSMVandthetotalwillbecalledasrespectivegarmentsSMV

BenefitofOperationBreakdown:

Canseethealloperationsofthegarmentsatatime.CananticipatethedifficultiesofdoingcriticaloperationCanmakelayoutinaeasy,simpleandlesstimeconsumingway.Easytoselectrightoperatorforrightprocess.Canknowthequantityandtypesofmachinetomakethegarmentrequired.Canbeconsciousaboutqualityforfillupthebuyerstandard.Breakdowncanknowaboutadditionalguide,folderandattachment.

CalculationofOperationBreakdown:AnalysisofOperationBreakdown:

Tocalculatecapacitystudy,firstwehavetotakeatleastfivereadingsofeachworkerofallprocess.ThenwehavetocalculatetheaveragevalueofthesefivereadingsAfterthen,theSMVcalculationThentargetcalculation(60/SMV)

SHIRTSEWIN-FULLSLEEVEFORMALSl.No.

OperationListSAMM/c

1Pinningtoprofile0.2342Runstitchcollar(profile)0.219SNLS3Trimcollar0.285SNLS4Clipandturncollar0.2235Creasecollar0.3816Topstitchcollar0.42SNLS7Runstitch(R/s)collarband0.291SNLS8Creasecollarband0.3179Insertcollarinneckband0.799SNLS10Turnandcreasecollar0.45211Hemcuff0.501SNLS12R/scuff0.565SNLS13Turncuff0.52714Creasecuffbottom0.56615Attachplackettosleeve0.795SNLS16Lockandmakediamond1.026SNLS17Sewpleats(4no.)0.389SNLS18Hemrightfront0.494SNLS19Attachfrontplacket0.603SNLS20Creasepocket0.54221Hempocketmouth0.28SNLS22Attachpockettofront0.861SNLS23Attachbrandlabelandtackloop0.589SNLS24Attachyoketoback0.475SNLS25Topstitchbackyoke0.365SNLS26Joinshoulder0.64SNLS27Topstitchshoulder0.656SNLS28Attachcollar0.535SNLS29Closecollarwithsizelabel1.01SNLS30Sleeveattach0.862SNLS31Topstitcharmhole0.678SNLS32Topstitchsideseam1.036FOA33Attach&closecuff0.696SNLS34Topstitchcuff0.524SNLS35Hembottom0.947SNLSTotalSAM19.783

hemmer

MachineNosSNLS26FOA1ButtonHole1ButtonSew1

FusingMachine1SteamPress131att/oth

Manual

ECTurnerHand/iron

Hand/ironHand/ironHand/ironHand/ironHand/ironbinder

OperationBreakdown:Bra

OP#SEWINGPROCESSSAMMACHINE1JoinCups0.57SNLS2AttachTapetoCups0.73DNLS3attachElastictosidecups0.443SZZ4SetsupportPanels0.39SNLS5Sergesupportpanels0.623TOL6Joinsupportpanels,cupandfront1.52SNLS7Attachcoverstitchtapetofront0.61DNLS8Joinbackstocups0.55SNLS9Attachcoverstitchtapetosides0.47DNLS10Attachlaceandtapetocups0.76DNLS11Attachelastictoband0.9ZZ12Attachupperelastic&straps0.913SZZ13Coversupportpanelsedges0.543TOL14Attachhooksandeyestostraps1.39SNLS15Seteyetoback0.36ZZ16Sethooktoback0.5SNLS17Attachtrimmingtofront0.25SNLS18Trimthreadandinspect1MANTotalSAM12.51

.-105SkillMatrixforSewingOperator

SkillMatrixisachartoradatabasewhereoperator’spastperformancesonvariousoperationsarerecordedinasystematicwayforthefuturereference.Inaskillmatrixoperatorperformanceisrecordedinefficiencypercentage.Skillmatrixisalsocalledasskillinventoryoftheoperators.AbasicskillmatrixisshowninFigure7a.Skillmatrixisupdatedonaregularinterval.Oraftercompletionofeachstyleoperator’scurrentperformance(efficiency%)updatedonthedatabase(formanuallydevelopedskillmatrix)

Thebenefitsofanoperatorskillmatrixareenlistedbelow.

Itkeepsrecordofalloperationsanoperatorhaddoneinthepastandefficiencylevelineachoperation.Engineers/linesupervisorsneedminimumtimetofindandselectmostefficientoperatorsforanoperationfromthepullofoperators.Forlinebalancing,operatorscanbeselectedaccordingtoworkcontent.Forexample–whereanoperationisrequired50%lesstimethanpitchtime,engineerscanselectanoperatorwhoseefficiencylevelis50%onthatoperation.Whenoperationclubbingisrequired(forlessworkcontentworks),skillmatrixgivestheinformationwhatalloperationtobegiventoanoperator.Whensomeoneisabsent,supervisorcaneasilyfindsuitablepersonfromtheskillmatrixtableandreplace.

Askillmatrixcanbemadeinspreadsheet.Orrealtimeshopfloordatatrackingsystemcanbeusedforskillmatrixdevelopment.Intheskillmatrix,ausercandosortingofoperatorperformanceinvariousoperationandotherwayinaoperationhowmanyoperatoraretherewhohadearlierworkedonandtheirefficiencylevel.

PreparationofoperatorSkillInventory(SkillMatrix):Astandardworkminutelibraryisdevelopedbymeasuringtheamountoftimetakenbyagoodworkertodovarioustasks,measuredbythestopwatchasgiveninthefollowingTable.

Oncetheskillmatrixhasbeendeveloped,forthesettingofproductionlinewithrespecttonewstylethepatternmakerdecidestheproductiontype,productionstepsinthesequenceandtheamountof

workforeachproductionstep.Thenheusesthestandardworkminutelibrarytodeterminethenumberofstandardworkminuteneededforeachtasks.

AllocationofOperator’s

Appropriateallocationoftheskilloperatorsforparticularoperationsisthekeystoneforanylinebalancinginthegarmentindustry.Allocationalsodependsontypeofbalancerequired.Oneapproachofallocationistofindtheclosestmatchbetweenoperatorsrequiredandoperatorsavailable.Thistypeofallocationresultsinintrinsicbalanceofline.Anotherapproachistheeffectiveutilizationofoperator’sskillsofarhecandothebest,thisapproachresultsindynamicbalanceofline.

FromtheTables2and3forasettingtheoperatorsareselectedasB-A-Dbecausetheoperationalefficienciesoftheseoperatorsareaspertherequiredfortheparticularjobswhichwillhavetheeffectiveuseofalloperators’skills.

Byconsideringthisdetails,andcalculatingtherequiredoutputincomparisonwiththetimeandefficiencylevels,wecandistributelabourforcebetweenoperations.Thisstepisdoneusuallyafterdoingthelinebalancing.

ThreadConsumptionSeveralfactorsdeterminetheextentofthreadconsumptioninanysewnproduct,suchasstitchtype,seamtype,materialthickness,numberoflayers,constructionandSPI(stitchesperinch).However,thesefactorsarenotconstantwiththedifferentstylepreferences.Hence,threadconsumptionisneverstandardforsewnproductcategoriessuchasshirts,trousersandfootwear.Therearetwomethodsgenerallyusedtocalculatetheamountofthreadinaseamandhencethethreadconsumptioninthesewnproduct:BymeasuringtheactualamountofthreadconsumedBycalculationusingthreadconsumptionratios1.MeasuringActualThreadConsumed

Aspecifiedlengthofagivenseamismeasuredandthenthethreadispulledoutofthislength.Wecanusetheamountpulledoutofthisspecifiedlengthtocalculatetheratioofthreadconsumedintheentireseam.Bydividingtheamountofthreadbytheseamlength,wegettheratioofthreadconsumed.Ifwemultiplythisfactortimesthetotallengthofseam,wecandeterminethetotalthreadconsumedforthatseam.

Example:Lengthofseam=100cm(1metre)Stitchclass401=2-ThreadChainstitchLengthofseamforwhichthreadisremoved=15cmNeedlethreadremoved=19.5cmNeedlethreadfactor=19.5/15=1.3Looperthreadremoved=62.0cmLooperthreadfactor=62.0/15=4.1TotalNeedlethread=100cmx1.3=130cmTotalLooperthread=100cmx4.1=410cmTotalthreadconsumed=130+410=540cmAdd15%wastage=540cmx1.15=621cm

Generally,10%to15%wastageofthreadisaddedtotheconsumptionderived.Thiswastageoccursduetoshop-floorconditionslikemachinerunning,threadbreakage,repairs,etc.Theaboveexampleshowsthetotalthreadconsumedforonetypeofstitchclassinagarment.Byfollowingasimilarprocedure,youcancalculatethethreadconsumedfordifferentstitchingoperationsinagarment.

2.ThreadConsumptionRatios

TheeasiermethodistousethegenerallyapplicableThreadConsumptionRatiosforthevariousstitchtypesthatarelistedinthetablebelow.Byrelatingtheseratiostothelengthofseamsusingeachstitchtype,totalthreadconsumptioncanbecalculated.StitchDescriptionClass301Lockstitch101Chainstitch401TwoThreadChainStitch304ZigzagLockstitch503TwoThreadOveredgeStitch504ThreeThreadOveredgeStitch512FourThreadMockSafetyStitch516FiveThreadSafetyStitch406ThreeThreadCoveringStitch602FourThreadCoveringStitch605FiveThreadCoveringStitch

TotalThreadUsage(cmpercmofseam)/ThreadRatio2.5

45.571214182018

2528

No.ofNeedleLooper/Under(incl.NeedlesThread%Cover)Threads%

1505011000125751505015545120802257522080230702208033070

Theaboveratiosarearrivedatwithastitchdensityof7stitchespercm(18stitchesperinch).Theseratiosaretheprescribedminimuminregularconditionsandmarginallyvarywiththefactorsaffectingthreadconsumption.Acertainpercentageofwastageistobeaddedtotheaboveratiosaspershopfloorconditions.Itmayvaryfrom10%to15%.ExampleThreadconsumptionforanaverage-sizedknittedt-shirtStitchTypeSeamThreadTotalThreadConsumptionNTLTLength(m)Ratio(m)301Lockstitch42.51055504ThreeThreadOveredgeStitch314428.533.6401TwoThreadChainStitch0.755.5413503TwoThreadOveredgeStitch0.951211.46.35.1101OneThreadChainStitch0.140.40.40Totalthreadconsumed67.821.146.7Wastage(15%)1037Totalafterconsideringwastage77.824.153.7

Thesedays,threadconsumptionandcostingcanbecalculatedwithouttheneedtopickthethreadfromseams.Thereareeasyprogramsavailabletousewith,

American&EfirdThreadConsumptionCalculatorLightWt.FabricsFillintheinformationhighlightedin‘yellow’CompanyName:ABCMFG.COMPANY

ThreadDescription(ex.TexOktochange(ie,Topstitching)Size/Brand/Clr)Thread#1T-24PermaCoreCopy&Pastefromcolumn“M”toColumn“O”=T-24PermaCore

GarmentDescription:CASUALSHIRT-SHORTSLEEVESIZE:Large

=====

CostPerGarment=0.0049US$RowsSeamNeedleNeedle

Oper#NameofOperationISOofLengthThreadThreadStitchStitchSPICMMetresTex/Type/Color

BobbinBobbinThreadThreadMetresTex/Type/Color

1RUNSTITCHCOLLAR&BAND

301111841.30T-24PermaCore2TOPSTITCHCOLLAR&BAND

111841.30T-24PermaCore3BUTTONSEWCOLLARBAND

1110.14T-24PermaCore4BUTTONHOLECOLLARBAND

1110.18T-24PermaCore1.25T-24PermaCore1.25T-24PermaCore0.05T-24PermaCore0.08T-24PermaCore5HEMSLEEVE

1101021.53T-24PermaCore6SEWLABELTOYOKE

110200.31T-24PermaCore7SEWYOKESTOBACK

110520.78T-24PermaCore8TOPSTITCHBACKSEAM

110530.80T-24PermaCore9HEMRIGHTFRONT

110761.14T-24PermaCore10BUTTONSEWRIGHTFRONT

6110.81T-24PermaCore11HEMFRONTPOCKET

114200.34T-24PermaCore12SETFRONTPOCKET

114460.77T-24PermaCore13HEMLEFTFRONT

210762.29T-24PermaCore14BUTTONHOLELEFTFRONT

6111.05T-24PermaCore15JOINSHOULDERS&TOPSTITCH

110971.45T-24PermaCore16SETCOLLARTOSHIRT

110911.37T-24PermaCore17SETSLEEVES1101228.06T-24PermaCore

18CLOSESLEEVE&SIDE

1101479.74T-24PermaCore19HEMBOTTOM

1101422.14T-24PermaCoreSUBTOTALS35.501.47T-24PermaCore0.29T-24PermaCore

0.75T-24PermaCore0.77T-24PermaCore1.10T-24PermaCore0.27T-24PermaCore0.33T-24PermaCore0.74T-24PermaCore2.20T-24PermaCore0.45T-24PermaCore1.39T-24PermaCore

1.32T-24PermaCore2.05T-24PermaCore15.7689.10

PercentWaste10%8.9198.01

ANECALCAvg.SeamThickness1.2mmPhoto

LooperLooper/CoverTotalThreadThreadMetres/MetresTex/Type/ColorOper.

2.552.550.180.252.990.601.531.572.241.080.681.524.491.502.842.6917.14T-24PermaCore25.20

20.71T-24PermaCore30.454.1937.84TOTALS89.10

TotalMetres/GarmentConsumedMetres/Garment-WasteTotalMetres/GarmentwWasteANE

CALCTHREADCOSTANALYSISProgramSz(units)Copy&PasteThreadSKU’sTOTALPut-UpFromAboveMETRES(5000M)

PriceThreadPricePerMetreThreadPricePerGarment

10,000#ofConesneeded1T-24PermaCore98.015000$0.25$0.00005$0.00490196.023456Currency

98.01TotalMetres/GarmentwWaste$0.0049US$

PerGarmentPcesareforcomparativepuposeony.ConactyourA&ERepesentativeforyouexactpices.

Threadconsumptionforashirt,workedthroughexcelutilities.LostTimeLosttimeisthetimeanoperatorloseswhichisoutofhiscontrol.Thistimewillaffecttheefficiencyofanoperatorunlessitistakenintoconsideration.OtherwiseknownasNon-ProductiveTime(NPT)Majorlosttimecategoriesare,

Waitingforwork,MachineTrouble,Doingotherpeople’srepairsDoingsamplesPowerfailureMeetings.Linesetting

Sincetheabovepointscannotbecontrolledbytheoperator,thetimespentissubtractedfromtheattendedminutesoftheoperator.Forexample,ifnolosttimeoccurredtheoperatorsefficiencyiscalculatedasfollows:

=64.8%

If,however,theoperatorhadwaitedforworkforDonesamplesforMachinetroublefor

TotalThecalculationwouldnowbeworkedasfollows:

350.540–100X10030minutes40minutes30minutes

100minutes=79.5%

1.Christinehasanattendedtimeof525minutes,losttimeof37minutesandproduced300mins.

Whatisherefficiency?2.Janethasattendedtimeof525mins,losttimeof27minsformachinetrouble,and62minsonsamples.Theminutesonherticketforthedayamountedto400.Thebonusschemeinthisfactorypays0.018centsperminuteonstandardforeverypercentageincreaseabove70%.WhatisJanet’sbonus?3.Thenormaldayhasatotalattendedtimeof525minutes,operator163left45minutesearlytogotothedoctor.Beforesheleftshedid:25bundlesofjoinshoulders

16bundlesofsetsleeves3bundlesofsideseams8minsperbundle10minsperbundle15minsperbundle

Hermachinewasbrokenfrom08:30until08:45andsheworkedonsamplesfrom12:00until12:30.Whatisherefficiency?1.)300

525–37=61,4%

2.)525–89=436Minsproduced=400Efficiency=91.7%(91,7–70)x436x0.018=R1.70

3.)Attendedtime=525–45=480Losttime:MT15

Samples30=45Timeonstandard=435Minutesproduced:

25x8=20016x10=1603x15=45200+160+45=405

Efficiency=405435x100=93%ProductionStudy

AProductionStudyisacontinuousstudyofarelativelylengthyduration,oftenextendingoveraperiodofoneormorehours,takenwiththeobjectofcheckinganexistingorproposedstandardtime,orforobtainingotherinformationaffectingtherateofoutput.

Fromtimetotime,thesupervisorwillfindaproblemwithanoperatorwhomshe/heknowsshouldbeabletoreachtherequiredstandardoroutput,butdoesnotdoso.Ofteninsuchcases,neitherthesupervisor,northeoperatorhim/herself,willbeabletosuggestanyparticularreasonforthelowperformance.IfapreliminarycheckbyconventionalTimeStudydoesnotshowanyreasonforthedifference,itisessentialthataProductionStudybemadetoestablishwhytheoperatorisunabletoperformthetaskintherequiredStandardTime.

Theinabilityoftheoperatortoaccomplishthetaskintherequiredtimemaybeduetoseveralfactors;

a.Changesinthefabricb.Changesinthemethod,layoutorworkingconditionsc.Inadequatetrainingd.ErrorsintheoriginalTimeStudye.Operatorlaziness

AlthougheveryeffortshouldbemadetopreventerrorsinsettingtheoriginalTimeStandard,itisessentialthatmanagementbewilling,atalltimes,torectifyerrorsortodemonstratethecorrectnessofthetimestandard.Operatorsmusthaveconfidenceinthestandardsandinthepeoplewhosetthem.

Whilsttheproductionstudyisusedtoinvestigatecomplaintsfromoperatorsregardingratesorproductionstandards,itisalsousedtodetermineotherfacts.Theseincludethefollowing:1)ToensurethatTimeStandardsdoinfactcoveralloftheactivitiesinvolved,2)Toobservetheincidenceofwaitingtimeandotherdetails,towhichtheoperatormaybesubject,

3)Toobtainnewdataonwhichtocompileinterferenceandcontingencyallowances,4)Torecordtheperformanceofaparticulardepartmentforfuturereference,5)Toestablishwhethertheoutputofanoperatorisshowingadownwardtrend,6)Toestablishwhattimesduringthedayfatigueaffectstheoperator’sperformance,7)Toinspireconfidence,operatorsshouldbelieveinthefairnessoftheStandardTimesset.Thevaluesmayformthebasisofanagreementbetweenmanagementandworker,bothpartiesmustbeabletoplacetheirtrustintheagreement.Ifthistrustislostbyeitherparty,thenWorkStudywillnotsucceed.ItisalsovitalthattheWorkStudystaffshouldgainconfidenceintheaccuracyofthetimeswhichtheyare

setting.Theprocedureinvolvestiming,recordingeachcycleandnotingeachdisturbanceasfollows:a)Intheexample,theoperatorbeganbymakingsixfronts,oneaftertheother,withcycletimesof32,30,28,32,35and29centiminutes.Theobservernotedthesefiguresinthe‘CycleTime’section.b)Duringtheseventhfront,theoperatorhadathreadbreak,theobserveroperatedhis/herwatchandnotedthetimeof22forthefirstportionthen29forre-threadingthemachine,asshownunder“threadbreaks”,then10forfinishingofffrontnumberseven.c)Duringfrontnumber10theoperatorhadtorenewthebobbin.Thecycletimeisthereforesplitintotwoportionsagainwiththetimeforthebobbinchange36,beingenteredintotheappropriatecolumn.d)Theoperatorthencontinuedthroughtotheendofthebundle,whentheobserverrecordedatimeof74forbundlehandling,cuttingofthecoupon,etc.e)Inthisexample,theobserverthenleftthreeblanklinestoallowspacetocalculatetheoperator’sperformanceforthatbundle,thencontinuedtorecorddetailsforthenextbundle.f)Inbundletwotheobservernotedthat50centiminuteswerelostbecausethesupervisorcametotalktotheworker.Inthisinstancethedisturbancecamebetweenonecycleandthenext,sothereisnoneedtosplitcycletimereadings.Therewas,athreadbreakontheseventhcyclewhichisdealtwithasbeforeandbundlehandlingof68.g)Inbundlethreethereweretwoseparatethreadbreaks,andhe/shewasalsogivenbackonefronttorepairandbundlehandling.h)Theobservercompletedthestudyatthispoint,andreturnedtotheofficetocalculatethefollowing:a.Thetotalsofhis/herreadingsundereachcategory-cycletime,threadbreaks,bundlehandling,etc.b.Thetotalobservedtimeshownonthestudyasawhole.c.Theoperatorobservedperformanceagainstthestandardtime(includingbundlehandling),calculatedas:

i)Finally,he/shewillcalculatethepercentagesforeachtypeofdisturbancetoassistindiagnosingtheoperatorproblem.

j)Calculatingthebundlehandlingandcolourchange(BH&CC)persinglewillassistindiagnosingwhethertheoperatortooktoolongonanyparticularactivity.Inordertocalculatethisthetotaltimeforbothactivitiesmustbeaddedtogetherandthenewtotaldividedbythetotalnumberofunitsproduced.Acomparisonisthenmadebetweenthefigureandtheallowedtimefortheseactivities.

k)He/shewillalsogiveaprojectionoftheoperator’sexpectedorpotentialperformanceoverawholeday.Thiswillnotbethesameastheperformancecalculatedunder3above,sincethestandardtimeincludesaprovisionforpersonalandfatiguetimes(usually11%).

11%ifthestudyislessthan1hourduration,or8%ifthestudyisbetweenoneandtwohours,or5%ifthestudyislongerthan2hoursanddoesnotincludeteabreaks.

Theobserverthenshouldhavealloftheinformationnecessarytodeterminewhichthemostseriousproblemisaffectingtheoperator,forexample:i.Iftheworkerstrueperformanceislowsay50-60%,theobservermusthelptheworkers

method,ormotivation.ii.IfthebundlehandlingtimeismuchhigherthantheallowanceprovidedintheStandardTime,dueconcentrationmustbegivenhere.Similarly,withthreadbreaks,personalandfatiguetimes,colourchangesoranyotherfactorbuiltintothestandardtime.iii.Alternatively,thestudymayrevealsomeotherproblemsnotprovidedfor,suchasahighproportionofrepairsorinterruptionsbyotheroperators,etc.Theeffectofthesewillthenbeclear,andtheEngineerwillnowfocushis/herattentiononsolvingtheproblemsathand.

Mostimportantly,ProductionStudyprovidesanexcellentwayofprovingtotheoperator,thatthestandardtimeiscorrect.Thisgivestheoperatortheconfidenceandknowledgethattheycanachievethestandardtimewhichhasbeenset.

ProductionStudyisavaluable“everyday”techniquewhichgivesquickandclearinsightintowhatishappeningonthefactoryfloor.

Elements,Rating,Allowances,Sampling,Cyclechecks,PMTS,

7WorkMeasurement

Workmeasurementisconcernedwiththedeterminationoftheamountoftimerequiredtoperformaunitofwork.Itenablesapparelengineerstocomparealternativemethods,andalsotodoinitialstaffing.Workmeasurementdataarethebasisforplanningandschedulingalsoitisimportantforwageandsalaryadministrationandfordevisingincentiveschemes.IthasbeendefinedbytheBritishstandardinstitutionsas“Theapplicationoftechniquesdesignedtoestablishthetimeforaqualifiedworkertocarryoutaspecifiedjobatadefinedlevelofperformance”

ObjectivesUsingasatargetthetimesestablishedforjobsatthedefinedlevelofperformance,workmeasurementwillbefoundtohavethefollowinguses,

Toassistinmethodstudybycomparisonoftimesforalternativemethods,andforallocatinglabourtojobsinproportiontotheworkinvolvedsothatthelabouronajobisproperlybalanced.Toenablerealisticschedulesofworktobepreparedbyrelatingreasonablyaccurateassessmentsofhumanworktoplantcapacity.AsthebasisofrealisticandfairincentiveschemesToassistintheorganizationoflabourbyenablingadailycomparisontobemadebetweenactualtimesandtargettimes.AsabasisforlabourbudgetingandbudgetarycontrolsystemsToenableestimatestobepreparedoffuturelabourrequirementsandcosts.Methodstudy

Methodstudyistheprincipaltechniqueforreducingtheworkinvolvedprimarilybyeliminatingunnecessarymovementsonthepartofmaterialoroperativesandbysuggestinggoodmethodsforpoorones.

Methodstudycanrevealshortcomingsofdesign,material,andmethodofmanufacturingandsuchaffectmainlytechnicalpeople

WorkMeasurement

Workmeasurementisconcernedwithinvestigatingandreducingandsubsequentlyeliminatingineffectivetime.Noteonlycanitrevealtheexistenceofineffectivetime,butitcanbeusedtosetstandardtimesforcarryingoutthework,sothat,ifanyineffectivetimedoesevolvelatter,itwillimmediatelybefoundoutbytheincreasedstandardtime.Workmeasurementismorelikelytoshowupthemanagementitselfandthebehaviorofworkers.

WorkMeasurementTechniquesTherearetwotypeofwork,accordingtoworkmeasurement.

1)Repetitivework:-wherethemainoperationorgroupofoperationsrecurscontinuouslyduringthetimespentatthejob.Thisappliesequallytoworkcyclesofextremelyshortdurationandtothoseofseveralminutesorevenhoursduration.

2)Nonrepetitivework:-itincludessometypeofmaintenanceonconstructionwork,wheretheworkcycleitselfishardlyeverrepeatedidentically.

Theprincipaltechniquesofworkmeasurementare;1)Timestudy2)Synthesisfromstandarddata3)Predeterminedmotiontimesystem(PMTS)4)Analyticalestimating5)Comparativeestimating6)Estimating7)Activityofworksampling8)Relatedactivitysampling9)MOST(MaynardOperationSequenceTechnique)Thepracticeofworkmeasurementcanberepresentedas,a)Thejobisbrokendownintoitselementsb)Forelementsofhumanwork,therecordsofbasicofnormtimesareconsultedforthistimeforeachelement.c)Forthoseelementsforwhichthereisnobasictimealreadyavailable,thebasictimeisdeterminedbytheappropriateworkmeasurementtechniquesd)Thevaluessodeterminedforanyoftheelementswhichcouldpossiblyrecurinanotherjobareaddedtotherecordsofbasictime.e)Theproportionofrestrequiredisassessedandaddedtothebasictime,toarriveatthetimefordoingtheworkatthestandardrateofworkingandforrecoveringfromtheeffortortheworkcontent.f)Theadditionofrelaxationallowancemaybemadeelementbyelementorthebasictimesfortheelementsmaybesummedandtherelaxationallowancesaddedjobwise,againtogivetheworkcontent.g)Thenecessarytechnicaldataarecollectedforanymachineinvolvedinthejob.h)Thevaluesforhumanwork,thetechnicaldataandanyotherappropriateallowancesarecombinedtoarriveatthestandardtimeforthejob.

Source-TimestudySource-PMTS

WorkMeasurementDataBasicTime

Analyticalestimating

RelaxationAllowances

WorkContentTherecordsofbasictimesforelementsaretermedassyntheticdataandthecompilationofasmuchsyntheticdataisanimportantobjectiveofanyworkmeasurementstudyprogram.

TimeStudy

Workmeasurementtechniqueforrecordingthetimesandratesofworkingfortheelementswithinspecificconditionsofaspecifiedjob,andforanalyzingthedatasoastoobtainthetimenecessaryforcarryingoutthejobatadefinedlevelofperformance.Thebasicstepsindoingtimestudyprocedureare,

SURVEYJOBCONTENT(Correctmethod,operatingconditions,quality,etc.)PLAN(allconstituentscanbemeasuredeconomicallyandaccurately)DEFINEELEMENTS(Coveringthewholejob,selectedforconvenienceofobservation,measurement,analysisandsynthesis)MEASURERecordingtherateandtimeforeachelementrepeatedinsufficientvolumetoprovidereliabledatacoveringallexpectedconditions)EXTEND(toobtainthebasictimeforeachelementbycalculations)COLLATEDATA(Toestablisharepresentativebasictimeforeachelementinthetask)DETERMINERELAXATIONALLOWANCE(Foreachelementinthetask)ALLOW(Forotherrelevantfactors,andsummatetoestablish)STANDARDTIME(forthefinaljob)

SelectingthejobtobestudiedGenerallythereisalotofpressureontheapparelengineertostudynumberofjobsinawell-organizedfactoryalsotheremaybehundredsoftimestandardsthathadtobecarriedout.Itbecomesnecessarytounderstandwhatarethereasonsforwhichtimestudymaybedonefirst.Therearesomereasontotakeintokeyconsideration,1)Thejobinquestionisanewonewhichmeanstheyarenotpreviouslycarriedout.2)Changeinthemethodofexistingtimestandards3)Complaintsreceivedfromworkersorunionsregardingthetimestandardoftheworkoritstargets

notachievable.4)Aparticularoperationappearstobea“bottleneck”operation,whichholdsupanumberofsubsequentactivities.5)Changeinmanagementpolicyabouthowtimestandardsaretobeused.Forexampleifwegowagesaccordingtotimestandardsthenweshouldbehavemoreaccuratetimestandards.

StepsinmakingaTimeStudy

a)Obtainandrecordallinformationofjob,operator,andsurroundingconditionslikelytoaffectthecarryingoutofthework.b)Recordthecompletedescriptionofthemethodandbreakingdowntheoperationintoelements.c)Measuringwithtimingdevicepreferablyadecimalchronometerandrecordthetimetakenbytheoperatortoperformeachelementofoperation.d)Atthesametimeassessingtheeffectivespeedratingoftheoperatorrelativetopredeterminednormalspeed.Thisnormallydependswiththeexpertiseoftheapparelengineer.e)Convertingtheobservedtimeto“normaltimes”or“Basictime”f)Determinetheallowancestobemadeoverandabovethebasictimeforoperationsg)Determinetheallowedtimeorstandardtimefortheoperation.

Therearesomeotherinformationmusttoberecordedalongwiththesheet,suchas,Studynumberorsheetnumberonjobsheet

NameofengineertookthestudyanddateNameofproduct,drawingorspecificationortechpacknumber,partnumberetc.DepartmentorlocationwheretheoperationistakingplaceanditsdescriptionSketchofworkplacelayout,plantormachinesandtoolsutilized.OperatorsclocknumberandratingStartingtimeandfinishingtimeofstudyanditsdurationetc.

Beforerecordingthemethod,careshouldbetakenthatsystematicmethodstudyhasbeencarriedout,ifnot,itshouldbedoneatthistime.Itismeaninglesstotalkabouttimestudyinabsenceofpropermethod.CorrespondingtoeachmethodtherewillbeonlyoneStandardTime.Methodstudyallowsustodefinevariouspossiblealternativesofchallengingagiventaskandchoosingthebestamongthealternatives.AndthebestistakenupforestablishingtheTimestandards.

BrakingthejobintoElementsElementsaredistinctpartofaspecifiedactivityoftaskcomposedofoneormorefundamentalmotionsormachineactivities,selectedforconvenienceofobservation,measurementandanalysis.Elementsshouldbeeasilyidentifiedwithdefinitebeginningandendings,sothatonceestablishedtheycanberepeatedlyrecognized.Thepointatwhichoneelementendsandanotherbeginsiscalledasa“BreakPoint”thesebreakpointscanbeeitherseenorheard.Generallyelementsshouldbenolessthan0.05minutesandnolongerthanabout0.60minutes.WorkCycleisacompletesequenceofelementsnecessarytoperformaspecifiedactivityortasksoastoyieldoneunitofproduction.Itmayalsoincludeelementswhichdonotoccurineverycycleforexamplebundlingisanactivityrepeatsonlyaftertheexpiryofanopenbundle.Thereasonsforbreakingdownthejobintoitselementsare,1)Toensurethattheproductivework(needlemovingorsewingisaproductiveworkbutaligningpieces

arenotproductive)isseparatedfromunproductiveactivity.2)Topermittherateofperformancetobeassessedmoreaccuratelythanoveracompletecycle.Becausetheoperatormaynotworkatthesamepaceandmaybefoundtoperformsomeoperationsfasterthanothers.3)Toenabletheelementsinvolvinglightfatiguetobeisolatedandtomaketheallocationoftherestallowancemoreaccurate.4)Timestandardstobecheckedsothatthelateromissionorincretionofelementsquicklydetected.5)Toenabledetailedjobspecificationstobeproduced.6)Toenablestandardtimevaluesforfrequentlyrecurringelementssuchastheoperationofmachinecontrolsofloadingandunloadingetc.fromfixturetobeestablished.

Varioustypesofelements1)RepetitiveElements:-arethosewhichoccurineverycycleofthegivenactivityoftask,e.g.Pickingfrombundleanddispatchtobinofsewnparts

2)ConstantElements:-arethosewhichmayoccurineverycycleornot,buttheyareidenticalinspecificationandtimefromcycletocycle,e.g.switchonmachine,puttrimmersonsideetc.3)VariableElements:-arethose,inwhichthetimeofperformancevariesinrelationwithcharacteristicsofproductequipmentonprocess.Suchasdimension,orweightoftheobject,e.g.sizevariationofshirtSsizeandXLsizeasnextbundle.4)OccasionalElements:arethoseelementswhichdonotoccurineverycycleofthetask,butmaytakeplaceeitheratregularintervalsofrandomly,e.g.replacingthepern(bobbin)inaweavingmachineisregularinterval,breakingofthreadsisrandom.5)ForeignElement:-theseareobservedduringthestudybutdonotformthenecessarypartofthegivenactivityofthecycle,e.g.operatorstoppingthemachineandtalktohisfriend.6)GoverningElement:-Whentwoelementsaregoingonsimultaneouslyinagivencycle,theelementthattakeslongertimeiscalledgoverningelement.7)ManualElement:istheelementperformedbytheworkermanually8)MachineElement:isanelementautomaticallyperformedbyamachinee.g.sewingabartack.

BreakthejobElements

1)Elementsshouldbeeasilyidentifiedandshouldhavedistinctbeginningandend.Thesebreakpointsmustberecognizedadifferentsound,sothattheobserverknowspreciselywhenitstartsandwhenitends.e.g.clinchingsoundbystoppingofthemachine,pressingatoolontable,movementofaspecificmachinepartetc.thesebreakpintsneedtobedescribedonthebreakingdownofthejob.

2)Elementsshouldnotbetoosmallnortoolarge(morethan0.05andlessthan0.60minutesasmaximuminsomecases,butingenerallessthan0.33minispreferred).Iftheelementsaretoolargetheperformanceratemayvaryduringthedurationoftheelementtherebycausinglossintheratingaccuracyoritmaydifficulttorateifthetimeistoosmall

3)Elementsshouldbeunifiedaspossible.Thismeansthatacertaingroupofbasicmotionssuchasreachfor,grasp,ormovemaybecombinedtogetherbecausetheyachieveagivenpurpose.4)Elementsofimportantnatureshouldnotbecombinedtogether5)Measureeachelementintermsoftime.

TheBSTdefinitionofanelementisadifferentparttoajobselectedforconvenienceofobservation,measurement,andanalysis.Forthepurposeoftiming,thewholejobisbrokendownintoelementamong0.05to0.5ofaminuteduration.Thereasonwhyacycleofworkhastobebrokendownintoelementsarisesfromtheneedtobeabletoidentifythecausesoftimevariationthatwillappearinactualpractice.Timingtheoverallcycledoesnotprovidetheopportunityforisolatingthesecausesandmeasuringtheirindividualeffect.TheelementbreakdownenablestheApparelEngineerto,

-Accountforvariationintime–thevariationofspeedatwhichtheoperatorworkscanbeeasilyseen.

-toensurethatproductiveworkisseparatedfromunproductivework-toincreaseaccuracyinratingtheoperation-toidentifydifferentlevelsoffatigueallowancerequirement-toproducemoredetailedworkspecificationeasiertocrosscheck-futureuseofcompilingstandarddataCertainmotionsoractivitiesneedtobegroupedintoanelementtomakeeaseofmeasurement.Itistotakenotethat,ifasoundcannotbeusedasabreakpoint,thenavisualonehastotakeitsplace.Whateverisselected,itmustcapableofpreciserecognitionotherwiseoneelementoverlapsintoanother.Eachelementshouldbegivenanumberorlettertoidentifyitsothattherequirementforwritingisminimizedduringstudy.

MeasuringwithstopwatchSincethegreatmajorityofoperationsintheclothingindustryarelessthanaminute,themostsuitabletypeofstopwatchunitisthe“decimalminute”.Adecimalstopwatchcanrecordtimeindifferentformats

-secondsandminutes-indecimalminutes-inTMU-SplitLaps.

Adecimalminuteisthemostfavoriteofallkindsofstopwatches.Nowadaysindigitalstopwatchesallthefacilitiesareincorporatedinone.Inadecimalminuteoneminuteisdividedinto100partsandeachdivisionrepresents0.01(onecentminute)andadecaminuterecorderisoftenusedwhereoneminuteisdividedinto1000parts.Thisisusedwhereshorterelementsaretobemeasureandtoincreaseaccuracy.Therearetwowaysfortakingreadingfromastopwatchi.e.snapback(flyback)timingandcumulative(continuous)timing.SnapBackTimingisamethodinwhichthehandsofthestopwatcharereturnedtozeroattheendofeachelementandareallowedtorestartimmediately,thetimeoftheelementbeingobtaineddirectly.

CumulativeTimingisamethodinwhichthehandsofthestopwatchareallowedtocontinuetomovewithoutreturningthemtozeroattheendofeachelement,thetimeforeachelementbeingobtainedsubsequentlybysubtraction.Mostpredeterminedmotiontimesystems(MTMandMOST)useTimeMeasurementUnit(TMU)asitsunitinsteadofsecondsorminutes.OneTMUisdefinedtobe0.00001hoursor0.036seconds.Thesesmallerunitsallowformoreaccuratecalculationwithouttheuseofdecimals.Inthemostin-depthPMTSsystems,motionsobservedwillbeonthelevelofindividualTMUs,liketoss(3TMUinminiMOST)andsimplepickup(2TMUisMTM-1).

TMUinAmericanSystem1TMU=0.036seconds1Hour=100,000TMUs1second=27.78TMU1Minute=1666.67TMUTMUinBritishSystem1TMU=0.030seconds1Hour=120,000TMU1Second=33.33TMU1Minute=2000TMUAsgeneraltheASTM

systemofTMUiscommonlyusedbutthestopwatchmayhavebothuniversally.TheBritishsystemismoreaccurateneartoaHDvideorecordingrateof2000framesperminutesothateachframecanbecountasaTMUwhilecountingfromtheframesofavideo.

Performancerating

Performanceratingisthestepintheworkmeasurementinwhichtheanalystobservestheworker’sperformanceandrecordsavaluerepresentingthatperformancerelativetotheanalyst’sconceptofstandardperformance.PerformanceRatingcanbedefinedastheprocedureinwhichthetimestudyengineercomparestheperformanceofoperator(s)underobservationtotheNormalPerformanceanddeterminesafactorcalledRatingFactor.Duringthetimestudy,timestudyengineercarefullyobservestheperformanceoftheoperator.Thisperformanceseldomconformstotheexactdefinitionofnormalorstandard.Therefore,itbecomesnecessarytoapplysome‘adjustment’tothemeanobservedtimetoarriveatthetimethatthenormaloperatorwouldhavetakentodothatjobwhenworkingatanaveragepace.This‘adjustment’iscalledPerformanceRating.Determinationofperformanceratingisanimportantstepintheworkmeasurementprocedure.Itisbasedentirelyontheexperience,training,andjudgmentofthework-studyengineer.Itisthestepmostsubjectiveandthereforeissubjecttocriticism.“Ratingisasubjectivecomparisonofanyconditionoractivitytoabenchmark,baseduponourexperience.”Whilethemechanicsoftimestudyrecordthetimeataskdidtake,applyingaratingwilldeterminethetimeataskshouldtake.Operatorsdon’tworkallthetimeatthesamespeed,neitherdotheyworkfrommorningtonight,dayinanddayoutwiththesameintensity.Therearemanycontributorycausesforthesevariations,butnomatterwhattheyare,theapparelengineermustbeabletodealwiththeeffect.(i.e.changefromtheestablishedmethodorchangeinthespeedofworking).Ratingisthementalcomparisonbytheengineerofanoperatorunderobservationwithhisownideaof“normalperformance”NormalPerformanceistheworkingrateofaverageworkerworkingundercapablesupervision,butwithoutthestimulusofanincentivewagepaymentplan.Thispacecanbeeasilymaintaineddayafterday,withoutunduephysicalormentalfatigue,andischaracterizedbythefairlysteadyexertionofreasonableeffort.Inspiteofthedifficultiesinvolved,muchprogresshasbeenmadeanditissurprisinghowclosetheWorkstudyengineershavetothesamestandardtimewhentimingthesamejobunderthesameconditions.Forexample;anormalperformanceofaman’swalkingis4.8kmperhourbutmostofuseasilycompareandtellisseensomeone“walkingslowly”orsomeone“walkingfast”thiscomparisonarisesfromthecomparisonwiththenormalspeedofwalkingisunderstoodinourmindas4.8andcompareswiththathappensinourmind.Inactual,theeffectivespeedoftheworkingistoberated.Thisisnotthespeedofmovement,becauseanunskilledoperatormaymoreextremelyfastandyettakelongertoperformanoperationthanaskilledoperatorwhoappearstobeworkingquiteslowly.Theunskilledoperatorputsinalotofunnecessarymovementswhichtheexperiencedoperatorhaslongsinceeliminated.Judgmentofeffectivespeedcanonlybeacquiredthroughexperienceandknowledgeoftheoperationsbeingobserved.“Effortsarenotrated”theresultofvariationsineffortcanbeseenintheeffectivespeed.

FactorsaffectingRating

Itmaybethatbecauseofadverseconditionseitheroutsideorwithinhimselfcontrols,aworkertakeslongertoperformanelementononeoccasionthananother,eventhoughhisspeedorworkingeffortaregreater.Somefactorsoutsideoperatorscontrolincludes,

-Variationsinqualityofthefabricused-Changesintheoperatingefficiencyofmachineswithintheirusefullife.-Minorchangesinmethodsorconditionsoroperations.-Variationinthementalattentionnecessaryfortheperformanceofcertainelementsofwork.-Changesinclimaticandothersurroundingconditionssuchaslighting,temperature,humidity,noiselevelsetc.

Thesecangenerallybeaccountedforbytakingasufficientnumberofstudiestoensurethatarepresentativesampleiftimesisobtained.

Therearesomefactorsaffectingoperatorperformancethosearewithinthecontroloftheworker,someofthemare,-Variationinthequalityofproductwithinthespecification.-Variationsduetooperatoractivity-Variationsduetotheirattitudeofmind,especiallyhis/herattitudetotheorganizationforwhichheworks.Thisincludesinterestandtopmanagementdeals.Theoptimumpaceatwhichworkerwillworkdependsonsomefactorssuchthat,-Thephysicaleffortdemandedbythework.Generallyademandforincreasedphysicaleffortwillleadtoaslowerspeed.-Thecarerequiredonthepartofoperator,aneedforincreasedcareincarryingoutanelementofworkwillalsoreducethespeed.Becausevariousfactorswillinfluencetheworker’smotionpatternsandeffectivespeedindifferentways,theWSobservermustbefamiliarwiththemotionpatternfollowedbyanaverageworkercompetentandfamiliartohiswork,andwithhowthepatternmaychangetomeetavariedrangeofconditions.Ratingisverymucheasierifagoodmethodstudyhasbeenmadefirst,inwhichtheactivitiesworksforspecialskillorefforthavebeenreducedtotheminimum.Themorethemethodhasbeensimplified,thelesstheelementofskilltobeassessed,andthemoreratingbecomesamattersimplyofjudgingspeed.Bycarefultrainingofstaffandbycrosscheckingofassessments,consistencyofratingbetweenobserverscanbeassuredtoahighdegree.

Howtheratingfactoristobeused

IftheWSengineerdecidesthattheoperationobservedisbeingperformedlessefficientlythanhisideaofstandardthenhewilluseafactoroflessthan100relatively,say75or80ofwhateverheconsidersrepresentsaproperassessment.Ontheotherhandifitseemsbeingdonemoreeffectivelythenhemaygiveratingof105or115etc.itisusualpracticetoroundofratingtothenearestmultipleof5onthescale.WithpropertrainingandcontinualpracticeacompetentWSengineercanassesstheeffortofanoperatorona5pointbasisfromabout60to125ratingscale.Outsidethesevalues,accuracyofratingdiminishesbutmostoperatorsratingfallwithintherange.Whiletraining,wehavetopreparearatingcharttoidentifytheconsistency,andaccuracyofrating.OncetheWSengineerisgettinganearlysteadyratinglinethenonlyhisratingsaremoreaccurate.Ifwehadperfectworkstudyengineersandperfectoperationsand

perfectconditions,theformulafollowswouldholdgoodforeachelement.

Inactualpracticetheobservedtimexratingisveryrarelyconstantforthesameelementbecauseofthevariationsinthemethodofperformingtheelement,andorvariationsintheworkcontentoftheelementandorinaccuraciesinthenotingarecordingtheobservedtime.Eachelementisratedseparatelywhilsttheelementisinprogressandnotedbeforethetimeistaken,otherwisethereisaverygreatriskthatprevioustimesandratingsforthesameelementwillinfluencetheassessment.ForthisreasontheratingcolumnoftheTimestudysheetplacedtotheleftofthewatchreadingcolumn.Itisperhaps,afurtheradvantageofthecontinuousmethodoftimingthattheelementtimedoesnotimmediatelyappearasaseparatefigure,whichmightinfluencetheratingortempttheWSengineertoratebythewatchattitude.Soundinitialtrainingandregularrefresherchecksprovidethemeansofkeepingratingerrorsdown,alwaysitneedtopreparearatinggraphofyoursafterdoingtherating.

Themoreratinggetsaccuratethegraphwillberunningmore45’totheaxis.Thiscanbeachievedonlybypractice.

ScaleofRatingBeforeanycomparisonbetweenperformanceobservedandthenormalperformancecanbeusedtomodifytheobservedtime.Itmustbetranslatedtonumericalterms.Therearedifferentscalesofrating,themostcommonlyusedbeingthosewhichratesthestandardperformanceas100.

100/133Scale(Percentagescale)

60/80Scale(BedauxScale)75/100Scale0/100scaleBSIScale

ThisisthemostwidelyusedscaleintheUSA,wherethenormalperformanceisratedat100%andtheincentivepaceis133%forthisreasonthisisknownaspercentagescale.

ThiswasthemostwidelyusedscaleinBritainanddevelopedinFrance,wherethenormalperformanceisratedat60andtheincentivepaceis80points

Thisisanalternativescaleusedwhenthenormalperformanceisratedat75andincentivepaceat100

ThisisthescalesuggestedbyBritishStandardsinstitutewherethestandardperformanceistheincentivepace.ThereisnonormalperformanceastheBSIstatesthatitdoesnotfollowthatwhenworkerarepaidontimeworktheywillworkatanormalperformance(i.e.60,75,or100dependsuponthescaleused)

LooseRating:-aninaccurateratingwhichistoohightotheactual.130

TightRating:-aninaccurateratingwhichistoolowtotheactual120

FlatRating:-asetofratingsinwhichtheobserverhasunder110estimatedthevariationsintheworkersrateofperformance.80133100SteepRating:-asetofratingswheretheobserverhas90overestimatedthevariationsintheworkersrateofworking.8060100

Inconsistentrating:-acombinationofallthepreviousfourtype70oferrors,usuallyattributabletothelackofexperienceifthe60observersnorunderstandingtheratingconcept.50SyntheticRating0-100scaleThismethodofratinghastwomainadvantagesoverothermethods.Theseare

itdoesnotrelyonthejudgmentoftimestudypersonanditgivesconsistentresults.

Thetimestudyismadeasusual.Somemanuallycontrolledelementsoftheworkcycleareselected.UsingaPMTsystem(Pre-determinedmotiontimesystem),thetimesfortheseselectedelementsaredetermined.Thetimesoftheseelementsasdeterminedarecomparedwiththeactualobservedtimesandtheperformancefactorisestimatedforeachoftheselectedelements.

PerformanceorRatingFactor,R=P/AWhereP=Predeterminedmotiontimeoftheelement,andA=Averageactualobservedtimeoftheelement.Theoverallratingfactoristhemeanofratingfactorsdeterminedfortheselectedelements.Thisisapplieduniformlytoallthemanuallycontrolledelementsoftheworkcycle.

AllowancesBeforeitispossibletocompleteandissuethatstandardtimeforajob,itisnecessarytoaddthebasictimewithcertainallowances.Thereadingsofanytimestudyaretakenoverarelativelyshortperiodoftime.Thenormaltimearrivedat,therefore,doesnotincludeunavoidabledelayandotherlegitimatelosttime,forexample,inwaitingformaterials,toolsorequipment;periodicinspectionofparts;interruptionsduetolegitimatepersonalneeds,etc.Itisnecessaryandimportantthatthetimestudypersonappliessomeadjustment,orallowances,tocompensateforsuchlossessothatfairtimestandardisestablishedforthegivenjob.Allowancesaregenerallyappliedtototalcycletimeassomepercentageofit,butsometimesthesearegivenseparatelyformachinetimeassomepercentageandformanualefforttimesomeotherpercentage.However,noallowancesaregivenforinterruptionswhichmaybeduetofactorswhicharewithintheoperator’scontrolorwhichareavoidable.Mostcompaniesallowthefollowingallowancestotheiremployees.

Constantallowances(forpersonalneedsandbasicfatigue)DelayAllowance(forunavoidabledelays)FatigueAllowance(forjobdependentfatigue)PersonalAllowanceSpecialAllowance

DelayAllowance:Thistimeallowanceisgiventooperatorforthenumerousunavoidabledelaysandinterruptionsthatheexperienceseverydayduringthecourseofhiswork.Theseinterruptionsincludeinterruptionsfromthesupervisor,inspector,planners,expediters,fellowworkers,productionpersonnelandothers.Thisallowancealsocoversinterruptionsduetomaterialirregularities,difficultyinmaintainingspecificationsandtolerances,andinterferencedelayswheretheoperatorhastoattendtomorethanonemachine.

FatigueAllowance:Thisallowancecanbedividedintotwoparts:(i)basicfatigueallowanceand(ii)variablefatigueallowance.

Thebasicfatigueallowanceisgiventotheoperatortocompensatefortheenergyexpendedforcarryingouttheworkandtoalleviatemonotony.Foranoperatorwhoisdoinglightworkwhileseated,undergoodworkingconditionsandundernormaldemandsonthesensoryormotorsystem,a4%ofnormaltimeisconsideredadequate.Thiscanbetreatedasaconstantallowance.

Themagnitudeofvariablefatigueallowancegiventotheoperatordependsupontheseverityofconditions,whichcauseextra(morethannormal)fatiguetohim.Asweknow,fatigueisnothomogeneous.Itrangesfromstrictlyphysicaltopurelypsychologicalandincludescombinationsofthetwo.Onsomepeopleithasamarkedeffectwhileonothers,ithasapparentlylittleornoeffect.Whatevermaybethekindoffatigue-physicalormental,theresultissame-itreducestheworkoutputofoperator.Themajorfactorsthatcausemorethanjustthebasicfatigueincludessevereworkingconditions,especiallywithrespecttonoise,illumination,heatandhumidity;thenatureofwork,especiallywithrespecttoposture,muscularexertionandtediousness,andlikethat.

Itistruethatinmodernindustry,heavymanualwork,andthusmuscularfatigueisreducingdaybydaybutmechanizationispromotingotherfatiguecomponentslikemonotonyandmentalstress.Becausefatigueintotalitycannotbeeliminated,properallowancehastobegivenforadverseworkingconditionsandrepetitivenessofthework.

PersonalAllowance:-Thisisallowedtocompensateforthetimespentbyworkerinmeetingthephysicalneeds,forinstanceaperiodicbreakintheproductionroutine.Theamountofpersonaltimerequiredbyoperatorvarieswiththeindividualmorethanwiththekindofwork,thoughitisseenthatworkersneedmorepersonaltimewhentheworkisheavyanddoneunderunfavorableconditions.

Theamountofthisallowancecanbedeterminedbymakingall-daytimestudyorworksampling.Mostly,a5%allowanceforpersonaltime(nearly24minutesin8hours)isconsideredappropriate.Thisotherwayalsoknownascontingencyallowances.SpecialAllowances:Theseallowancesaregivenundercertainspecialcircumstances.Someoftheseallowancesandtheconditionsunderwhichtheyaregivenare:

PolicyAllowance:Somecompanies,asapolicy,giveanallowancetoprovideasatisfactorylevelofearningsforaspecifiedlevelofperformanceunderexceptionalcircumstance.Thismaybeallowedtonewemployees,handicapemployees,workersonnightshift,etc.Thevalueoftheallowanceistypicallydecidedbymanagement.

SmallLotAllowance:Thisallowanceisgivenwhentheactualproductionperiodistooshorttoallowtheworkertocomeoutoftheinitiallearningperiod.Whenanoperatorcompletesseveralsmall-lotjobsondifferentsetupsduringtheday,anallowanceashighas15percentmaybegiventoallowtheoperatortomakenormalearnings.

TrainingAllowance:Thisallowanceisprovidedwhenworkisdonebytraineetoallowhimtomakereasonableearnings.Itmaybeaslidingallowance,whichprogressivelydecreasestozeroovercertainlengthoftime.Iftheeffectoflearningonthejobisknown,therateofdecreaseofthetrainingallowancecanbesetaccordingly.

ReworkAllowance:-Thisallowanceisprovidedoncertainoperationwhenitisknownthatsomepercentofpartsmadearespoiledduetofactorsbeyondtheoperator’scontrol.Thetimeinwhichthesespoiledpartsmaybereworkedisconvertedintoallowance.PeriodicActivityAllowance:-theseallowancesaremadeforworkcarriedoutperiodicallyduringthesewingofabundleofwork,anexampleisbundlingwhichcanifrequired,beexpressedasapercentageandaddedasanallowance.Machineinterfaceallowance:-whenanoperatorisrequiredtoattendmorethanonemachine,anyofwhichmaystopforsomereasonorother,atanytime,thereisapossibilitythatboththemachinesneedattentionatthesametime.Thisdelayisaddedasanallowance.Differentorganizationshavedecidedupontheamountofallowancestobegiventodifferentoperatorsbytakinghelpfromthespecialists/consultantsinthefieldandthroughnegotiationsbetweenthemanagementandthetradeunions.ILOhasgivenitsrecommendationsaboutthemagnitudeofvariousallowances,

ILORecommendedAllowancesCategoryofAllowance%

A.Constantallowances:

1Personalallowance52Basicfatigueallowance4B.Variableallowances:1Standingallowance22Abnormalpositionallowance:a.Slightlyawkward0b.Awkward(bending)2c.Veryawkward(lying,stretching)73Useofforce,ormuscularenergy(lifting,pulling,orpushing):Weightlifted,pounds:50101152Pounds20325430535740945115013601770224Badlight:a.Slightlybelowrecommended0b.Wellbelow2c.Quiteinadequate55Atmosphericconditions(heatandhumidity)-variable0-1006Closeattention:a.Fairlyfinework0b.Fineorexacting2c.Veryfineorveryexacting57Noiselevel:a.Continuous0b.Intermittent-loud2c.Intermittent-veryloud5d.High-pitched-loud58Mentalstrain:a.Fairlycomplexprocess1b.Complexorwidespanofattention4c.Verycomplex89Monotony:a.Low0b.Medium1c.High410Tediousness:a.Rathertedious0b.Tedious2c.Verytedious5

Whilewespecifytoapparelindustry,wehavemoreclearlyspecifiedtheallowancesas,1.Personnelandfatigueallowance(mostlyabout11%forsittingand13%forstanding)2.Contingencyallowance(mostlyabout3%to5%)3.Machineallowances(dependsofthetypeofmachine)4.Specialallowances(asneedbyILOdependsofsituation)PersonalAllowance:-Personalallowanceisonekindofrelaxationallowancewhichismostcommonallowanceingarments.Thisallowanceisprovidedfortheneedtoleavetheworkplacesuchasgoingtowashroom,fetchingadrink,etc.Thecommonfigureisabout5%to7%ofbasictime.FatigueAllowance:Fatigueallowanceisnotcommonallowanceingarments.Itisamentalandphysicaltirednessdevelopedbyanemployeeduetocontinuouswork.Thisallowanceisgivendependingontheenergyexpendedindoingthejobandtoalleviatemonitory.Normallyitiscountedas4%onbasictime.Insewingtradeweset11%forsittingworksand13%forstandingoperations.ContingencyAllowance:-Contingencyallowancedependsontheworker,physicalstrengthfordoingthejob.Itisasmallamountofallowancewhichisgiventomeetthelegitimatedelayofwork.Itiscountedlessthan5%ofbasictime.MachineDelayAllowance:Sometimegarments,machinesareoffduetomechanicalortechnicalproblems.Theseareappliedtothetotalbasictimeforthoseelementswhichareconcernedwiththeoperationofmachinery.Herearesomecommonfiguresofgarmentssewingfloor.Singleneedlelockstitchmachine=5%SingleNeedleUBTmachine=5%Twinneedlelockstitchmachine=14%Threethreadoverlockmachine=7%

Fourthreadoverlockmachine=9%Fivethreadoverlockmachine=11%SingleNeedlechainstitchmachine=5%ButtonSewChainstitchMachine=5%ButtonHoleLockStitchmachine=5%Bartackmachine=6%Safetystitchmachine=8%ThiscanbecalculatedusingtheILOrecommendationchartandotherwaysasfollowed,givingahigherallowancemeansyouarereducingtheefficiencyandactualproductivityofthefactory.AnalysisofaTypicalMachinist’sDayTotalAttendedTime535minTotalWorkingTime475Min60MinTotalOnStandardTime426Min49minTotalBasicTime349Min36min41Min

SewingTime140MinHandlingTime209MinTea&LuchBreaksOFFStandard

Machine&personalAllowanceHandlingTime60%

Theabovepicturesimplyexplainshowmuchanoperatorisworkingactuallyafterallallowancesmade.

StandardTimeStandardtimeexpressthetotaltimeajobwilltakeatstandardperformance,i.e.workcontentaddedwithcontingencyallowancesfordelay,unoccupiedtime,andallowancesetc.theunitusedtostatethistimeareStandardAllowedMinutes(SAM)orStandardMinutesValue(SMV)rememberbotharesame.Notdifferent.Theformulastorememberare,

Wewilldothecalculationinthelastphaseofthischapterforbetterunderstanding.

ActivitySampling.Incertainsituationsitisnotfeasibletousenormalworkmeasurementtechniquestoselectandunderstandwhatisactuallyhappeningintheshopfloorandhowtheproportionoftimedevotedtoeachtypeofwork.Themanufacturingofclothingbecomesmoreoperatorsinvolvedandsophisticateditbecomesmoredifficulttocollectthistypeofinformation,andyetatthesametime,itismorenecessarytogetarecordofit,soastobeabletosettheproperpriorities.Thistechniqueissimilartosamplinginspectionmethod,whereacomparativelysmallsampleofproductinspectedrevealswithincertainlimitsofaccuracytheproportionofdefectivearticlesinthewholelot.Theparticulartechniquemostoftenusedinthistypeofstudyiscalledactivitysampling.Inmostsituationsusefulandreliableinformationcanbeobtainedthroughthetechniqueofactivitysampling.Inonlyafractionofthetimewhichwouldberequiredwithconventionaltimestudy,andwithoutanyspecialqualificationsorexpertise.“Activitysamplingisdefinesasamethodoffindingthepercentageoccurrenceofcertainactivitybystatisticalsamplingandrandomobservation.”Activitysamplinghasbeenusedtostudyfactoryworkformorethanfortyyears,wemustknowexactlyhowtheoperatorspendshistime.Thisinformationcanbegathersby

makingfrequentshortobservationswhiletheoperatorisworking.Ifanoperatoractuallyspends20%oftheirtimewaitingforwork,thenanobserverwhomakes100randomglancesathim,shouldseehimworkingon80ofthoseoccasionsandwaitingontheother20.Conversely,ifanobservermakesenoughseparateobservationstoestablisharepresentativesample,andfindsoneparticularactivityhappeningon20%oftheoccasions,itisreasonabletoassumethattheactivityaccountsfor205oftheoperatorstime.Thepointaboutthistechniqueisthattheobservercannowstudyfiveortenoperatorstogether,simplybylookingfromonetoanotherinturninfrequentintervalsoftime.Therequiredinformationcanthereforebeobtainedmoreeconomicallythananyothertimestudymethods.MethodofdoinganactivitysamplingTheobservermustfirstdecidethatactivitieshe/sheisinterestedinfortakingthestudy.Thiscanbedoneinasewingroom,cuttingroom,finishingsectionoranyotherdepartments.Foreachsectionitneedtopreparealistofdistinguishedactivitieshappeningortobeobservedfromthedepartment’soperators.Thenselectgroupofoperatorsonwhomtoconductthestudy.Itiseasytodofromfivetotenoperatorsatatime.Whileselectingtheproductionlineofoperatorsitisbesttoselectifthereareanyproblemsoflesserproductivityidentifiedlinesfirstforthestudy.Thestudysheetshouldbefilledwitheachoperatorsname,clocknumber,operationdoing,andmachinetypeattheheads.Assoonastheobserverisfamiliarwiththeappearanceoftheactivitiessothathecanidentifythisinaninstant,thestudycanstart.Withthestopwatchrunningcontinuouslytheobservershouldlookateachoperatorinturnandrecordtheactivityheseesinthatinstant.Theobservationscanbemadeatfixedtimeintervalsontheoperators.Itisveryconvenienttomakeobservationsatintervalsof10centiminutesbecauseitistheneasytoremembertolookatoperator1astheneedlepasses10,operator2astheneedlepasses20andsoon,Eachobservationisrecordedbymakingasmallmarkintheappropriatespaceandthesearebestaccumulatedin“fivebargate”systemofmarkingfortheeaseincountinglatter.Thestudyshouldbecontinueduntilthereareatleast500readingsintotalthemorereadingsthemorereliabletheinformationobtained.With10operatorsandexperiencedpersonwillcompleteastudyin50minutes,withoutstoppinghiswatchandwithoutdroppingormisplacinganyindividualreading.Whenpreparingtosampleweneedtoreachthestatisticaltoleranceof+/-95%confidencelevelforourdesiredaccuracy.Ifweareusingthesampletogenerateatimestandardthenweshouldaimforanaccuracyof+/-5%,andifthesampleisbeingusedforcalculationofcontingenciesoranalysisoflosttimeweshouldaimfor+/-10%accuracy.Analysisofthestudy.Thestudyshouldbetotaledacrossandthepercentagescalculatedforeachactivity.Individualstudyresultsmayvarysomewhatfromonetoanother,largelybecauseproductionconditionsthemselvesvaryfromhourtohouranddaytoday.Underwidelyvaryingconditionsitisnecessarytoextendthestudybydaysofweeksinordertoobtainamorerepresentativepictureofwhatactuallyoccurs.Thisisbestachievedbymaintainingacumulativerecordofthetotalnumberofreadings

againsteachactivity,takingplacestudiesatadifferenttimesinthedayoveraperiodofweeks.Therespectivepercentagescanthenbecalculatedeveryfiveoftenstudiesandtheresultsenteredontoagraph.Thegraphwillshowclearlywhenthefigurehavesteadiedoutattheiroverallleverandwhensufficientresultshavebeenobtained.403530252015105

0255075100125150175200225250275300325350375400425450475500OBSERVATIONS

Wellbeforethis,thestudieswillalreadyhavepromptedactiononthemoreoutstandingproblems.Inthemostcasesmanagementwillnothaverealizedjusthowmuchtimeisbeinglostonthefactoryfloorinwaiting,fetchingwork,changingcolouretc.andthisdatacanbeusedtocontroltheexcesslevels.

Intheabovesamplesheet,theproductionfunctionsaretargetedtoget85%oftimebuttheactualisgettingonly75.48%whichmeansabout10%oflesstargetreached,whileanalyzingmore,theotherdisturbancesareallowedtoamaximumof10%butitgoesbeyondand5%istargetforothersbutitexceeds10%.Whichmeanstheissueswithinthecontrolofoperatorismoreandhencereducingtheefficiency.Whichmeansforaworkingdayof480minutes48minutes(10%)areexcessivelywastedbytheoperatoritself,inthatcasewemayfurtherdoanalysisaboutthatparticularoccurrenceandwhytheoperatorisabsentfrommachineifitisbymeanstofetchthebundlefromtheracksorsuch,thentoreducethatthebundlesmaybemovedneartotailor.

For95%confidencelimit

Inordertoobtainthepredeterminedaccuracyofthevalueofidletime(p)thesamplesizeornumberofreadingandobservationsshouldbe,

Where,N=thenumberofobservationsrequired.p=thepercentageoccurrenceoftheactivitytobeanalyzed.L=thedesiredlevelofaccuracy.

Wedon’tactuallyknowthepercentageoccurrenceofouractivitiesuntilwehaveperformedthestudy,butifweworkontheworstcasescenario,whereourpercentageoccurrenceofanyoneactivityis50%,forasamplerequiringanaccuracyof+/-5%:

n=4x50(100-50)/5x5.n=10000/25Numberorobservationsrequired=400.

Usingthesameformulaforanaccuracyof+/-10%thisfigureis100.

AdvantagesAnactivitysamplingstudycanbemadeofseveralmachinesandoroperatorsbyasingleobserver

ItrequiresfewermanhoursandcostslessthantimestudyObservationmaytakeplaceoverdaysorweeks,thusdecreasingtheeffectsofdaytodayorweektoweekvariations.ItprovidesmanagementwithanaccuratereflectionoffactorsthataffectproductionTheobserverdoesnotneedtobespeciallytrainedengineerActivitysamplingcanbeinterruptedatanytime,withoutaffectingtheresults.Itusuallyrequireslesstimetocalculatetheresultsofanactivitysamplingthanotherproductionstudies.Itmaybemadewithapreassigneddegreeofreliability,thatmeans,theresultsaremoremeaningfulWorksamplingstudiesarelessfatiguingandlesstedioustomakeonthepartofobserverSamplingstudiesarepreferredtocontinuoustimestudiesbytheoperatorsbeingstudied.Somepeopledonotliketobeobservedcontinuouslyforlongperiodoftime.Astopwatchisnotneededforworksamplingstudies.Ifanelectronicdatacollectorisused,resultsareshownonacomputereasily.

Disadvantages

Itisnoteconomicalforstudyingasingleoperatorormachineorforstudyingoperatorormachineslocatedoverwidearea.Timestudypermitsafinerbreakdownofactivitiesanddelaysthanispossiblewithactivitysampling.Theuseofperformanceratingenablestimestudytodetermineamoreaccuratetimeforthejob.Theoperatormaychangetheirworkpatternuponsightoftheobserver.Ifthisoccurs,theresultofsuchasamplingstudymaybeoflittlevalue.ItisveryrarethatadetailedspecificationofmethodusedismadewhenconductingactivitysamplinginvestigationThereistendencyonpartofsomeobserverstominimizepropersamplesizeorrandomnessofobservation.

CycleChecks

Acycletimeisabrieftimestudywiththepurposeofsettingatargetquickly,orcheckingwhetheranoperatoriscapableofachievingastandardtime.Thecycletimeisthetimetakenbytheoperatortoperformonecycleofoperationorthetime(minutes)requiredforacertainnumberofstepsinaprocesstobecompleted,fromstarttofinish,asdefinedbytheteamforperformingthespecifictask.Toconductthecyclecheckfollowthesteps.

Selectoperationstobestudiedanddetailthescopetobestudied.Maptheprocess(findtheelementsofthecycleandidentifyacyclestartandfinishpointsTakeseveraltimemeasurementsofeachcycleofoperationandrecordthetimeforeachcompleteoperation.Alsodoratingoftheworkcycle.Studytheprocessbetweenmeasuringpointstodetermineifthereiswastedtime.Ifsosuchreadingsareomitted.Circledownthesmallestcycletimeswhichrepeat(thisshouldbetakenwithcarethat,theremaybenearerpossiblevaluescanbetaken).Trytogetatleastfivecyclethemvaluessame.Calculatetheaveragecycletimefromfivevalues.Abnormaltimemaybeoccurredduetobobbinchange,threadbreak,powercutorqualityissues.Ignorethosefromthecalculation.Comparedcycletimetothebasictimeoftheoperationset.OrcalculateBasictimeandstandardtimescanbecalculated.

Whilewetakesthecycletime,wecanhavetwomethodstorecordthereading.1.Wecanbreakelementandrecordeachelementstimeandthesumuptogetcycletime.2.Wecanrecordthefullcycletime.

Generallywhiledoingthecycletimestudy,wedoratingas100%.Butthesamecanbedonewithactualratingsforpersonalshavinglessproductivityoriffoundunexpectedbottleneckonanoperator.TheactualratingwillgivethechangesfromSAMallowedfortheoperation.Andwhythetargetisnotbeingachievedifreducedratingfactorispresentfortheoperatorthenitneedtoconductaworkstudyforsolutions.

StandardTimeAsexplainedearlier,standardtimeexpressedintotaltimeforajobtogetdoneincludingallallowances.Togetthestandardtimeoftheoperation,

GetnecessarydetailsofthejobMakenumberofobservationsandbreakdowntoelementsTimeatleast15cyclesofoperationDoratingofalleventsCircleoutunusualeventsConcerttobasictimeusingformulaAddthebasictimesforeachelementsGivenecessaryallowancestothebasictimeEstablishStandardtime.

CirclingOutUnusualelementtimeshouldbeignoredatthecalculationstageofthestudy,butmustberecordedwhenmakingthestudy.Someoftheunusualhappeningare,

NeedleBreakThreadBreakBobbinChangeThreadChangeetc.

Thesethisarecoveredbyallowancesandaretherefornottobeincludedinthecalculationofbasictime.

ApproachtoWorkerTheworkstudyengineershouldalwaysspeaktothesupervisorofthelinebeforeapproachingtheoperatoraboutthestudy.Thisistoensurethateverythingisgoodbeforedoingthestudy.Theworkstudyofficershouldalwaysbepolite,well-manneredandfriendlytotheoperator.He

shouldlistentotheoperatorbecausetheremaybesomethingabouttheworkneedtobediscussed.SometimesitmaybeimportantformethoddevelopmentWillingnessoftheoperatortobestudiedisimportantStandinfullviewofoperator,butoutsidehisnormalvisionandpathofmovementOncethestudyiscompleted,totaltimerecordedshouldbecomparedtothetotaltimetakenforstudy.Ifthereisadifferenceofmorethan2%thestudyisnotsufficientlyaccurate,ifsoitmustberedone.Itismostimportantthattheworkstudyofficermakestheoperatorrelaxedbeforeandduringthestudy.

Thetimestudyformsarerecommendedhasprovisionfor15cycleswhichcanbebrokendowninto7elements,withcolumnsfortheratingandtheobservedtime.Attheendofcolumnsthereisprovisionforcalculatingthebasictimeforvariouselementsandthestandardtimeforthecompleteoperation.

StandardAllowedMinutes/StandardMinutesVolume

Thisisthestandardtimederivedthroughvariousmethodsforaspecificoperationtobedone.SAMorSMVarecommonfortheworkforthesameindustryconditionsalltime,

butmaybedifferentindifferentlocationsandsituation,henceitisnecessarytocalculateSAMfortheindustryratherthanadoptingsomeonesreading.MostadvancedsystemsofcomputeraidedplanningsoftwarehavefacilitytocalculateSAMbeforetheactualproductionisgoingtohappenandthenitispossibletocompareandadjustwiththeactualsurroundings.TIMESTUDYSHEETDATE3/3/2016SlNo01OperatorManojClockNo354MachineSNLSRPM3200

Attachments

OROTOROTOROTOROTOROTOROTCYCLETIME1900.150750.705700.712750.340750.3342750.229800.645750.802800.359800.3963800.123601.040651.313800.435850.4244850.179750.562750.669750.515700.4365700.260800.600800.724750.432750.3476750.358800.442800.742800.378700.3217800.246900.529750.861800.323800.4468850.315900.464800.872800.277950.2599101112131415TotalTime1.8604.9876.6953.0592.96319.564TotalRating640630600625630AvgTime0.2330.6230.8370.3820.370AvgRating8078.757578.12578.75FrequencyBasicEl.Time0.1860.4910.6280.2990.2921.895

TotalBasicTime1.895min

Allowances%Machine5.0%Contigency3.0%Personal&Fatigue11.0%Bundling0.05Other

Values0.095StandardTime2.3050.0570.208Target26PerHr.0.0500.000StyleClothStich/cmGarmentSizeOperationNill#3243Cottonwovenpoplin6Shirt30CollarPreperation

SKETCH

TimeStart13.30TimeFinish13.51TEBSTEASElapsedTime21

Accuracy93%

Thereareotherformatsalsousedtotaketimestudy.Theformatshastobedevelopedaccordingtotherequirementoftheindustry.

CommonMistakesTherearesomecommonerrorsmadebytheapparelengineerwhiletakingstudy,theyaremostlyObserverforgetstodotheactualrating,itisnecessarytoeachandeveryelementandforeachoccurrences.Someengineersmayputaconstantof80%or90%asastandardrating,thisisalsonotallowablebecauseitneedactualratinginsteadofactualreadingifweputsomeimaginaryfigureweareactuallygivingchancesforlosstofactoryandgoodoperatorssometime.Nevercheckstheaccuracy.ItisrequiredtochecktheaccuracybecausewhilewetakestimestudyitneedtotakecontinuouscyclesofoperationdonottakerandomcyclechecksanddotimecalculationsThecumulatedStandardTimefordoingtheoperationcyclecanbetermedfurtherasSAMorSMV.

PredeterminedMotionTimeSystemAtimestandardforajoboranoperationmaybeestablishedbytimestudy,byworksampling,orbytheuseofPre-determinedtimes.Predeterminedtimestandards(PTS)areadvancedtechniqueswhichaimatdefiningthetimeneededfortheperformanceofvariousoperationsbyderivationfrompre-setstandardsoftimeforvariousmotionandnotbydirectobservationandmeasurement.Theyarenotnormallyconsideredsuitableforthetraineetouseuntilhehasgainedarealunderstandingofandconsiderableexperienceinworkstudypractice.“ApredeterminedTimeStandardisaworkmeasurementtechniquewherebytimesestimatedforbasichumanmotions(classifiedaccordingtothenatureofthemotionandtheconditionsunderwhichitismade)areusedtobuildupthetimeforajobatadefinedlevelofperformance.”ThefirstPMTS(sincedesignatedas“first-level”systems)weredesignedtoprovidetimesfordetailedmanualworkandthusconsistedoffundamentalmovements(reach,grasp,move,etc.)andassociatedtimes.Largeamountsofresearch,datacollection,analysis,synthesis,andvalidationarerequiredtoproducePMTSdataandthenumberofsuchsystemsisverylow.“Higherlevel”systemshavesincebeendevised,mostcommonlybycombiningthesefundamentalmovementsintocommon,simplemanualtasks.Suchhigherlevelsystemsaredesignedforfasterstandardsettingoflongercycleactivity.ManyPMTSareproprietarysystemsandusersmusteitherattendadesignatedandapprovedtrainingcourseand/orpayaroyaltyforuseofthedata.

OneofthemajorPMTSsystemsisMTM(Methods-TimesMeasurement)whichisactuallya‘family’ofsystemsoperatingatdifferentlevelsandapplicabletodifferenttypesofwork.MTM1-the‘highest-level’ormostdetailedmemberofthefamily-wasdevelopedinthe1940sbyanalyzinglargenumbersofrepetitivecyclesofmanualworkonfilm.MTMgivesvaluesforsuchbasichand/armmotionsas:Reach,Move,Turn,Grasp,Position,Disengage,andRelease,togetherwithasmallsetoffullbodymotions.ThetimetakentoReachtoanobjectisthengivenbyatablebasedonthekindofReach(e.g.whethertheobjectisinafixedlocation-suchasatoolinatoolholder-orisasingleobjectlocatedonabench,orjumbledtogetherwithotherobjects,etc.)andthedistancetobeReached.Similartablesgivetimesforeachoftheotherbasicmovementscategorizedandmeasuredsimilarly.MTMissuitableformeasuringshortcycle,highly-repetitive

work.OthermembersoftheMTMfamilyuselowerlevelmotions(sothatinMTM2,forexample,theMTM1motionsofReachandGrasparecombinedintoacompositemotion,GET).MTM2isthusquickertoapply,butmoresuitedtolonger-cycleworkwherethefinelevelofdiscriminationofMTM1isunnecessaryintermsofmeetingaccuracyrequirements.

Predeterminedmotiontimesystemscanbecategorizedasmotionbased,actionbasedandactivitybasedsystems.MotionBasedActionBasedActivityBased

MTMGSDBMTMTM0MEKMODAPTSUSD

MSDMTM-1,MTM-3SomeofthemajorPMTSsystemsare,MaynardOperationSequenceTechnique(MOST)

BasicMOSTMiniMOSTMaxMOST

MaynardOperationSequenceTechnique(MOST)isapredeterminedmotiontimesystemthatisusedprimarilyinindustrialsettingstosetthestandardtimeinwhichaworkershouldperformatask.Tocalculatethis,ataskisbrokendownintoindividualmotionelements,andeachisassignedanumericaltimevalueinunitsknownastimemeasurementunits,orTMUs,where100,000TMUsisequivalentto1hour.Allthemotionelementtimesarethenaddedtogetherandanyallowancesareadded,andtheresultisthestandardtime.ItismucheasiertouseformoftheolderandnowlesscommonMethodsTimeMeasurementtechnique,betterknownasMTM.ThemostcommonlyusedformofMOSTisBasicMOST,whichwasreleasedinSwedenin1972andintheUnitedStatesin1974.Twoothervariationswerereleasedin1980,calledMiniMOSTandMaxiMOST.ThedifferencebetweenthethreeistheirleveloffocusthemotionsrecordedinBasicMOSTareontheleveloftensofTMUs,whileMiniMOSTusesindividualTMUsandMaxiMOSTuseshundredsofTMUs.Thisallowsforavarietyofapplications.

MiniMOSTiscommonlyusedforshort(lessthanaboutaminute),repetitivecycles,andMaxiMOSTforlonger(morethanseveralminutes),non-repetitiveoperations.BasicMostisinthepositionbetweenthem,andcanbeusedaccuratelyforoperationsrangingfromlessthanaminutetoabouttenminutes.

MODAPTS

YetanotherpopularPMTSusedtodayintheautomotive,sewingandhealthcareindustriesistheMODAPTStechnique.Thistechniquewasintroducedin1966byG.C.“Chris”HeydewhooriginallylearnedtheMTM-1andMTM-2methodsinthe1950sandsoughtasimplertechniquetouseandapply.UnliketheMTMandMOSTstandards,MODAPTSusesaMODasitsbasicunitofmeasurement(1MOD=0.129seconds).However,likeBasic-MOST,MODAPTSusesacodingtechniquethatconsistsofaletterandanintegernumber(allbut1code),wheretheintegernumberseachrepresentMODSthatcanbeeasilyaddedtodetermineacodedtask’stime.

MODSEW

MODSEWisasoftwareapplicationofMODAPTSforthesewnproductsandapparel

industries.Itusesveryintuitivecodestorepresentthevariousmotionpatternsprevalentintheindustryandallowstheusertoconfiguretheirowncodesforthoseuniquetotheiroperation.Thesoftwareisusedtodeterminethestandardtimetocompleteanoperationandhasprovisionstocollectandmaintaingroupsofoperationsinastyle(product).MODSEWisowned,maintained,soldandsupportedbyByteSoftwareServices,LLCofMauldinSouthCarolina.

GeneralSewingData(GSD)GeneralSewingDataisaPMTSforthesewnproductsandapparelindustriesandisbasedonMTMCoreDatabothproprietarydatasystemsofGSD(Corporate)LtdofPreston,UK.TheTimestandardsforGeneralSewingDataareusedinGSDEnterpriseandGSDQUEST.GSDcompanywastakenoverbythreadgiantCoatsin2015.Itsprimaryfunctionistorationalizemanufacturingmethodsandtoproduceanaccurateevaluationofthetimerequiredtoperformaspecifictaskoroperation.Thesystemconsistsoftwoparts,theinherentGSDDatabaseitself,whichformstheheartandintegrityofthesystem,andtheGSDforWindowssoftware,whichisthevehiclethat“drives”thedata.Throughitsapplication,youareabletocreateauniquelibraryofinformationtomeetyourownneedsandreflectyouruniqueenvironment.GSDisusedtocreatetheinformationrequiredforproductcosting,pre-productionplanning,scheduling,deliveryandprofitabilityandbecausethesystemispredictiveinitsnature,eachofthesefunctionsmaybeundertakenpriortomakingacommitment.SewEasySeweasyisamorerecentsystemusedbyFortune500companiesandSMEsectoralikeinReadyMadeGarment(RMG)manufacturing.SeweasyismorealignedwiththeleanconceptsattributedtoToyota.ThissystemfocusesonprovidingStandardMinuteValues(SAM,SMV)quicklyforlabourcostinginsewing.Suchgarmentsewingdataisusefulfor“sewingloadbalancing”inlinewithValueStreamMapping(VSM)and“addedvalue”measurement,referredas“needledowntime”amongprofessionals.SewEasyPvt.Ltdhastrainedmanyjuniorsandseniorsalike,toquicklyestablishstandardsusingthiseasyPMTSsystem.RecentresearchbyManchesterUniversity,UKonGarmentLaborCostsandLivingWagesCalculationsbroughtSeweasygarmentsewingdataandMethods-timemeasurement(MTM)tothenoticeofapparelindustry’ssourcingprofessionals,includingWalmart,whoadoptedsame

MethodsTimeManagement(MTM)Methods-TimeMeasurement(MTM)isapredeterminedmotiontimesystemthatisusedprimarilyinindustrialsettingstoanalyzethemethodsusedtoperformanymanualoperationortaskand,asaproductofthatanalysis,setthestandardtimeinwhichaworkershouldcompletethattask.Filmsweretakenusingconstantspeedcameras,runningat16framespersecond,oftheworkperformedbyqualifiedworkersontheshopfloor,eachsequencewasratedduringfilmingbythreequalifiedIndustrialEngineers.Therating,orLevelling,systemusedwastheWestinghouseorLMSsystem–socalledafteritsoriginatorsLowry,MaynardandStegemerten.Thissystemconsidersfourfactorsindependently:

Skill–ProficiencyinfollowingthegivenmethodEffort–ThewilltoworkConditions–Thegeneralworksurroundings

Consistency–ofperformance

Eachfactorisassignedanalpharating,e.g.“B-“,“C+”,“A”,etc.whichhasanumericvaluewhichisappliedlater.Thisreducesthepossibilityof“clockrating”andensuresthatallfactorsareconsideredinthecompositerating.Layout,distances,sizesofpartsandtoolsandtoleranceswereaccuratelymeasuredandrecordedontheshopfloortocomplementthelateranalyses.Thefilmswerethenprojectedframeby-frameandanalyzedandclassifiedintoapredeterminedformatofBasicMotions.Amotionwastakentobeginontheframeinwhichthehandfirststartedperformingthemotionandwastakentoendontheframeinwhichthemotionwascompleted.Thisallowedatimeforeachrecordedmotiontobecalculatedinseconds,bymeansofaframecount,andthen“levelled”toacommonperformance.Plotsofthelevelledtimesforthevariousmotionsweredrawn.Analysisdeterminedthebestdefinitionsoflimitsofmotionsandtheirmajor,time-determiningvariables,andresultedin,moreorless,thestructurewhichthemanualmotionsofMTM-1havetoday.Laterwork,usingTimeStudy,gavethetableofBodyMotions.BasicBodymotionsare,

ReachGraspMoveReleaseStepLegmovementBend&AriseCrankApplyPressureEyemovement

WhileMTM1hasreachandgrasp,inMTM2itcombinedbothasGET,anothercombinationinMTM2is2MoveandReleaseisclubbedtoPUT.TheunitinwhichmovementsaremeasuredforMTMisTMU(timemeasurementunit):1TMU=36milliseconds;1hour=100,000TMU,1TMU=0.036seconddependingonlengthoneTMU=0.03

PROSMV

ProSMVisanotherPMTSforthesewnproductindustry,offeredbyMethodsApparelConsultancyIndiaPrivateltd.asanindividualmoduleoftheirsoftwareseriespackcalledPro-Suite.ProSuiteisaimedatprovidingvariousITsolutionsforvariousdepartmentsofSewnproductindustry.IthasmadeaverystrongconsumerbaseinIndiaandneighboringcountries.SMVconsistsof36codesin7categories.AlistofthenormalMTM2datacodesandothersupplementaryelementsareincludedtobeusedforanalysisofnon-sewingoradditionalwork.

ThemajorfactorstotakeinconsiderationwhileusingPTSare,

TheapplicationofPMTSrequiresthattheoperationbeingmeasuredbedividedintobasicmotions.AtthetimeaPTSisfirstadoptedbyacompanythelevelofperformanceasrepresentedbythetimestandardsproducedbythesystemshouldbedeterminedandadjustmentsmade,ifnecessary,inordertomatchthecompanyperformancelevel.Mostpredeterminedtimesystemsdonotincludeallowancessotheseareaddedastheywouldbeinatimestudy.

AdvantagesofPTSSystemare,

WithPTSonetimeisindicatedforgivenmotion,irrespectiveofwheresuchmotionis

performed.Instopwatchstudyitisnotsomuchamotionasasequenceofmotionsmakingupanoperationistimed.Timingbydirectobservationandratingcansometimesleadtoinconsistency.APTSsystemavoidsbothratinganddirectobservationandhencecanleadtomoreconsistencyinsettingstandardtimes.Sincethetimesforthevariousoperationscanbederivedfromstandardtimetables,itispossibletodefinethestandardtimeforagivenoperationevenbeforeproductionbeginsandoftenwhiletheprocessisstillatthedesignstage.Thisallowstheworkstudymantochangethelayoutanddesignoftheworkplaceandofnecessaryjigsandfixturesinsuchawaythattheoptimumproductiontimeisachieved.Itisalsopossiblebeforestartingtheoperationtodrawupanestimatethecostofproduction,andthiscouldbevaluableforbudgeting.Theyarenottoodifficulttoapplyandcanbelesstimeconsumingthanothermethodswhentimestandardsaredetermined.Theyareparticularlyusefulforveryshortrepetitivetimecycles.

DisadvantagesofPTSsystemare,

PTSsystemstookalongtimetobecomepartofgeneralworkstudypractice.Themainreasonforthisdelayisprobablytheconsiderablenumberofsystemsthathavebeenproduced,togetherwithfactthatmanyofthemwouldobtainedonlybyemployingconsultants.Atpresenttherearemorethan250suchsoftwarebutallofthemneedspecialtraining.AnyPTSsystemisrathercomplicated.ItisnoteasytolearnandtheWSengineerneedsagooddealofpracticebeforehecanapplyitinfloor.Thetaskoflearningenoughaboutthevarioussystemstobeabletojudgetheirclaimsandtheirrelativemeritsisanalmostimpossibleone.PTSsystemsdonot,eliminatetheneedforthestopwatch,ormethodstudyorworksamplingmethods.Machinetime,processtimeandwaitingtimearenotmeasurablewithPTSsystemsandoccasionalorincidentalelementsareoftenmoreeconomicallymeasuredusingothertechniques.Itisdifficulttoobtain1005coverageinaplantusingonlyaPTSsystemandforcertainoperationssuchasbatchproductionornon-repetitivejobstheuseofsuchasystemcanbeanexpensiveproposal.ItisinvalidtoadduptimesforindividualsmallmotionsinthewayrequiredbyPTSsystembecausethetimetakentoperformaparticularmotionisinfluencedbythemotionsprecedingandfollowing.

HencethemainusesofPTSsystemaredividedintotwoclasses,WorkMethods

ImprovingexistingMethodsEvaluatingproposedmethodsinadvanceofactualproductionEvaluatingsuggesteddesignoftools,attachments,folderrequirementsetc.AidinginthedesignoftheproductTrainingmembersofthestafftobecomemotionmindedAidingintrainingoperatorsWorkMeasurement

EstablishingTimestandardsCompilationofstandarddataandformulasforspecificclassesofworkCheckingstandardsestablishedbytimestudy

AuditingtimestandardsBalancingproductionlineSupportingbettercostingWorkFactorSystemInPTSsystems,therearesymbolsemployedforthebodymembersandworkfactors,

BodyMemberFingerHandArmForeArmSwivelTrunkFootLegHandTurnSymbolWorkFactorSymbolFWeightorResistanceWHDirectioncontrol(Steer)SACare(Precaution)PFSChangeDirectionUTDepictiveStopDFTLHT

Aspertheworkfactorsystemhasfourmajorvariablewhichaffectthetimetoperformmanualmotions,theyare1.Bodymemberused2.Distancemoved3.Manualcontrolrequired4.WeightorresistanceOncewedoesthework,wecanobservetherearedifferentelementssupportingtodotheact,theyareknownasStandardElementsofwork,theyare,

1.Transport(reach&move)TRP2.GraspGR3.Pre-PositionPP4.AssemblyASY5.Use(Manual,process,ormachinetime)US6.DisassembleDSY7.MentalProcessMP8.ReleaseRL

Thecodesshownincombination,wecanrepresentmostoftheworksdonebyanoperatorwhileperformingthework.Whileconsideringtheaboveall,MTM-1isthemoststableaccuratesystem,providesmostdetailedmethodsdescription,butitrequiresthelongesttimeforanalysis.MTM2wasdevelopedbyconstructingmotioncombinationsfromthebasicmotions.IthassmallernumberofdistancerangesandfewercasesofcontrolthanMTM1buttheanalysiscanbemademorequicklythanMTM1.TheMTM2systemconsistofninecategoriesofmanualmotions.

MotionGetPutApplyPressureRegraspEyeActionCrankStepFootMotionBend&AriseSymbol

GPARGet&PutaretheonlytwovariablecategoriesandEonly37timestandardsappearonMTM2datacardCSFB

ThespeedofanalysiswithMTM2istwiceasfastwithMTM1.MSD’s,Principles,MotionEconomy,WorkingArea

8IndustrialErgonomics

Injuriesandmusclepainaffectingthewrists,shoulders,neckandbackarecommonproblemsforworkersintheclothingindustry.Humansplayacriticalroleinmostmodernmanufacturingsystemsandthereisnowagrowingunderstandingthatbetterconsiderationofhumanissuescangreatlyimproveefficiencyandsafety.Tocopewiththecomplexdynamicsofinternalandexternalsystems,manufacturingorganisationsoftenneedtomakechangesthatinvolveand/oraffectitspersonnel.Forthisreasonbusinessesareincreasinglyseekingergonomics/humanfactorsresearchandguidancetoimprovetheirunderstandingofhowbesttoincorporatehumanbehaviorandperformanceintosystemdesignandoperations.Ergonomicscanbedefinedsimplyasthestudyofwork.Morespecifically,ergonomicsisthescienceofdesigningthejobtofittheworker,ratherthanphysicallyforcingtheworker’sbodytofitthejob.Ergonomicsisasciencethatfocusesondesigningajobfortheworker.Anergonomically-designedjobwouldensurethatatallerworkerhadenoughspacetosafelyperformhisorherjob,andalsothatashorterworkercouldreachallofhisorhertoolsandproductswithoutreachingbeyondacomfortableandsaferange.Theoppositetothis,andwhattypicallyhappensintheworkplace,isthataworkerisforcedtoworkwithintheconfinesofthejoborworkstationthatisalreadyinplace.Thismayrequireemployeestoworkinawkwardpostures,performthesamemotionoverandoveragainorliftheavyloads–allofwhichcouldcauseworkrelatedmusculoskeletaldisorders(WMSD).

Industriesincreasinglyrequirehigherproductionratesandadvancesintechnologytoremaincompetitiveandstayinbusiness.Asaresult,jobstodaycaninvolve:

Frequentlifting,carrying,andpushingorpullingloadswithouthelpfromotherworkersordevices;Increasingspecializationthatrequirestheworkertoperformonlyonefunctionormovementforalongperiodoftimeordayafterday;Workingmorethan8hoursaday;Workingataquickerpaceofwork,suchasfasterassemblylinespeeds;Havingtightergripswhenusingtoolsetc.

Thesefactorsespeciallyifcoupledwithpoormachinedesign,tool,andworkplacedesignortheuseofimpropertoolscreatephysicalstressonworkers’bodies,whichcanleadtoinjury.

AdramaticincreaseinMSDsbeganinthe1970swhenthesedisordersincreasinglyappearedoncompanies’injuryandillnesslogs.Ifworktasksandequipmentdonotincludeergonomicprinciplesintheirdesign,workersmayhaveexposuretounduephysicalstress,strain,andoverexertion,includingvibration,awkwardpostures,forcefulexertions,repetitivemotion,andheavylifting.

Recognizingergonomicriskfactorsintheworkplaceisanessentialfirststepincorrectinghazardsandimprovingworkerprotection.Ergonomists,industrialengineers,occupationalsafetyandhealthprofessionals,andothertrainedindividualsbelievethatreducingphysicalstressintheworkplacecouldeliminateuptohalfoftheseriousinjurieseach

year.Employerscanlearntoanticipatewhatmightgowrongandaltertoolsandtheworkenvironmenttomaketaskssaferfortheirworkers.

WhatareMSDs?

MSDs,ormusculoskeletaldisorders,areinjuriesanddisordersofthesofttissues(muscles,tendons,ligaments,joints,andcartilage)andnervoussystem.Theycanaffectnearlyalltissues,includingthenervesandtendonsheaths,andmostfrequentlyinvolvethearmsandback.

Occupationalsafetyandhealthprofessionalshavecalledthesedisordersavarietyofnames,includingcumulativetraumadisorders,repeatedtrauma,repetitivestressinjuries,andoccupationaloverexertionsyndrome.Thesepainfulandoftendisablinginjuriesgenerallydevelopgraduallyoverweeks,months,andyears.MSDsusuallyresultfromexposuretomultipleriskfactorsthatcancauseorexacerbatethedisorders,notfromasingleeventortraumasuchasafall,collision,orentanglement.MSDscancauseanumberofconditions,includingpain,numbness,tingling,stiffjoints,difficultymoving,muscleloss,andsometimesparalysis.Frequently,workersmustlosetimefromworktorecover;someneverregainfullhealth.Thesedisordersincludecarpaltunnelsyndrome,tendinitis,sciatica,herniateddiscs,andlowbackpain.MSDsdonotincludeinjuriesresultingfromslips,trips,falls,orsimilaraccidents.PartsoftheBodyAffectedbyMSDs

•Arms•Back•Hands•Wrists•Fingers•Legs•Neck•Shoulders

Theclothingindustryisgenerallyseenasasafeplacetowork.Comparedtootherindustries,therearerelativelyfewseriousaccidentsinclothingplants.Thehazardswefacearedifferent.Themajorhealthrisksinthisindustrydonotarisefromimmediate,potentiallyfatalhazards.Instead,therisksthatclothingworkersfacecomefrommoresubtlehazardswhoseeffectaccumulatesovertime.

FundamentalergonomicprincipalsErgonomicsaimsatpreventinginjuriesbycontrollingtheriskfactorssuchasforce,repetition,postureandvibrationthatcancauseinjuriestodevelop.Somefundamentalergonomicprincipalsthatshouldbefollowedinourworkplacesare:1.UsepropertoolsToolsshouldbeappropriateforthespecifictasksbeingperformed.Toolsshouldallowoperatortokeeptheirhandsandwristsstraightthepositiontheywouldbeiniftheywerehangingrelaxedattheirside.Bendthetoolnotthewrist!Thetoolshouldfitcomfortablyintohand.Ifthegripsizeistoolargeortoosmallitwillbeuncomfortableandwillincreasetheriskofinjury.Toolsshouldnothavesharpedges,createcontactstressesinhand,orvibrate.2.KeeprepetitivemotionstoaminimumOurworkstationsortaskscanoftenberedesignedtoreducethenumberofrepetitivemotionsthatmustbeperformed.Usingapower-drivenscrewdriverortoolswitharatchet

devicecanreducethenumberoftwistingmotionswiththearm.Sometaskscanbeautomatedorredesignedtoeliminaterepetitivemovementsandmusculoskeletalinjuries.3.AvoidawkwardposturesJobshouldnotrequireoperatortoworkwiththeirhandsaboveshoulderheightonaregularbasis.Armsshouldbekeptlowandclosetobody.Bendingandtwistingofwrists,backandneckshouldalsobeavoided.4.UsesafeliftingproceduresAvoidliftingobjectsthataretooheavy.Usemorethanonepersonoramechanicaldevicetoreducetheload.Workstationshouldnotrequireoperatortoliftobjectsabovetheirheadortwistbackwhilelifting.Instructtheoperatortokeeptheloadclosetobodyandensurethatoperatorhaveagoodgrip.Heavyandfrequentlyliftedobjectsshouldbestoredbetweenkneeandshoulderheightnotonthegroundorabovehead.5.GetproperrestOperatorsneedtoresttheirbodyandmindinordertopreventinjuries.Givemusclesarestduringcoffeebreaks,lunchesandweekendsbydoingsomethingdifferentfromwhatnormallydoesinjob.Forexample,ifyoustandalldaywhileperformingyourjobyoushouldsitdowntorestyourlegsandfeetduringyourbreaks.Ifyousitdownwhenworkingyoushouldstandupandwalkaroundduringyourbreakstogiveyourbackarestandtoincreasecirculationinyourlegs.

CommonErgonomicProblemsandSolutionsintheClothingIndustry

Awkwardbodyposturesareamajorergonomicconcerninthegarmentindustry.Awkwardposturestakethebodyawayfromacomfortableposition,whichreducesefficiencyandincreasestheuseofenergy.Anothermajorconcernarestaticpostures.Staticmeanstoholdinplace,sothesearepostureswherethebodyisheldinonepositionforalongperiodoftime.Anexampleiswhenyouworkwithyourarmsaboveshoulderheightforlongperiodsoftime.Thesetypesofposturesrequireconstantmuscleuseforthetimethebodyisheldintheposition.Thisreducesrestandrecoverytime,whichleadstomuscletiredness.Thefollowingarerecommendationswhichwillhelptoreducetheriskofinjuryduetotheaboveconcerns.

Forseatedandstandingwork,theheightoftheworkstationshouldallowworkerstofunctionwithelbowsat90degrees.Iftheworkstationistoolow,theworkerisforcedtobendatthewaisttoreachtheworkbeingdone.Thisputsstressonthelowerback.Ifthestationistoohigh,theworkerisforcedtolifttheirshouldersormovetheirelbowsawayfromthebodytoreachtheirwork.Thisputsincreasedstressontheshoulderswhichmayleadtoinjury.

Duringseatedwork,ifagoodbacksupportisnotpresentorused,staticposturesoccurwhichresultsinconstantuseofthebackmuscles.Itisimportanttoadjusttheworkstationinordertoallowtheworkertousethebackrest.Itisalsoimportanttoadjusttheworker’schairtoallowdutiestobeperformedwiththeirbodiesincomfortablepositions.Theworkstationandchairshouldbepositionedsothattheworker’sknees,hips,andelbowsareat90degrees,whichwillreducestressonthebody.Thereshouldalsobeenoughroomtoallowtheworkertochangetheirsittingpositionthroughouttheday.Staticposturescanalsooccurduringstandingwork.Iftheworkerstandsinonepositionforlongperiodsoftime,musclesofthebackandlegswillbeconstantlyactivated.Thiscanleadtoincreasedfatigue,anddecreasedbloodcirculationtothelegs.Duringtheday,workersshouldtrytowalkaroundtoallowtheirbloodtoflow.Aswell,workersshouldtryandsitforshortperiodsoftimewhileworkingtogivetheirlegandbackmusclesarest.

Awkwardwristposturesareoneofthemajorcausesofcumulativetraumadisorders(CTD)suchasCarpalTunnelSyndrome(CTS),tendinitis,andmusclestrains.Awkwardwristposturesarethosewhichtakethewristawayfromtheneutralposition.Neutralpositioniswhenthehandisinlinewiththeforearm.Theworkstationshouldbeadjustedandtheworkereducatedonawkwardwristpostures,theirharmfuleffects,andthesignsandsymptomsofCTD’s.Workersshouldnotconstantlyworkwiththeirarmsaboveshoulderlevel.Workabovetheshouldersincreasestheuseoftheshouldermuscles.Withthisconstantuse,themusclesdonothavetimetorestandthustiremorerapidly.Themajorityofworkshouldbedonebetweenknuckleheightandshoulderlevel.

Workersshouldtrynottotwisttheirupperbodywhenplacingobjectsbesidesthem.Bykeepingtheirfeetinplaceandonlymovingtheirupperbody,workersareputtinglargestressesontheirbacks,whichmayleadtoinjuries.Workersshouldmovetheirfeet,insteadoftwistingatthewaist,inordertofacetheareawheretheobjectisgoingtobeplaced.Iftheworkerissitting,theyshouldtrytoswivelintheirchair,insteadoftwistingtheirupperbody.

PrinciplesofmotionEconomy

Theprinciplesofmotioneconomyformabasiscodeorabodyofrules,which,ifappliedbyonetrainedinthemotionstudytechniqueandproblemsolvingprocess,willmakeitpossibletoincreasetheoutputofmanuallabourwithaminimumfatigue.

PrinciplesrelatedtoHumanBody.

1.Twohandsshouldbeginaswellascompletetheirmotionsatthesametime.2.Twohandsshouldnotbeidleatthesametimeexceptduringrestperiods3.Motionsofthearmshouldbemadeinoppositeandsymmetricaldirectionandshouldbemadesimultaneously.

Itisbettertoarrangesimilarworkontheleftandrighthandsidesoftheworkplace,thusenablingtheleftandrighthandstomoretogether.Insewingthetwobundlesofpartsforattachingcanbeplacedonboththesideshenceenabletopickthepiecesusingtwohandssimultaneously.

4.Handandbodymotionsshouldbeconfinedtothelowestclassificationwithwhichitispossibletoperformtheworksatisfactorily

Generalclassificationofhandmotionsare,

a)Fingermotionsb)Motionsinvolvingfingerandwristc)Motionsinvolvingfinger,wristandforearmd)Motionsinvolvingfinger,wrist,forearmandupperarme)Motionsinvolvingfinger,wrist,forearm,upperarm,andshoulder.

Fingermotionsaremorefatiguing,lessaccurate,ablowerthanmotionsofforearm.Forearmisthemostusedforlightworksandthatinhighlyrepetitiveworks.

5.Momentumshouldbeemployedtoassisttheworkerwhereverpossible,anditshouldbereducedtominimumifitmustbeovercomebymusculareffort.(Momentum=Massxvelocity).Forexample,ifaforciblestrokeisrequired,themotionsoftheworkershouldbesoarrangedthatthestrokedeliveredwhenitreachesitsgreatestmomentum.

6.Smoothcontinuouscurvedmotionsofthehandsarepreferabletostraightlinemotionsinvolvingsuddenandsharpchangesindirection.7.Ballisticmovementsarefaster,easierandmoreaccuratethanrestricted(fixation)orcontrolledmovements.Exampleforfixationmovementiswritingandforballisticisswinginghammerwhilenailing.8.Workshouldbearrangedtopermitaneasyandnaturalrhythmwhereverpossible.9.Eyefixationsshouldbeasfewandasclosetogetheraspossible.

Principlesofmotioneconomyrelatedtoworkplace1.Thereshouldbeadefiniteandfixedplaceforalltoolsandmaterials.Theoperatorshouldalwaysbeabletofindthetoolsandmaterialinthesamelocation.Similarlyfinishedpartsandassembledpartsshouldbedisposedinfixedplaces.2.Tools,material,andcontrolsshouldbelocatedclosetothepointofuse.Themainaimofmotionergonomicsinindustryistoreducethehumanmovementsandeffortstherebyreducingfatigue.

WorkingArea

Consideringthehorizontalplace,thereisaverydefiniteandlimitedareawhichtheworkercanusewithanormaleffort.Thenormalworkingareafortherighthandisdeterminedbyanarcdrawnwithasweepoftherighthandacrossthetable.Theforearmonlyisextendedandtheupperarmhangsatthesideofthebodyinanaturalposition.Thearcsofleftandrighthandswillcrosseachotheratapointinfrontoftheworker.Theoverlappingareasconstitutesazoneinwhichtwohandsworkmaybedonemostconveniently.

Thereisamaximumworkareaforthehandstoo,itisdeterminedbythesweeparcofthehandwiththearmpivotedattherightshoulder.Theoverlappingareaconsistsazonebeyondwhichtwohandedworkcannotbeperformedwithoutcausingconsiderabledisturbanceandaccompaniedbyfatigue.

Arrangementofmachines.Thefollowingstatementsmightbeconsideredwhilearrangingthemachinesandtools,Inthecontinuoustypeofmanufacturing,machines,processequipment,rawmaterial,etc.shouldbearrangedsoastorequiretheleastmovementonthepartoftheoperator.Gravityfeedbinsandcontainersshouldbeusedtodelivermaterialclosetothepointofuse.(abin

withsoppingbottompermitsthematerialtobefedtothefrontbygravityalsorelievestheoperatorofhavingtoturnintothecontainertograspparts.DropdeliveriesshouldbeusedwheneverpossibleMaterialandtoolsshouldbearrangedtopermitthebestsequenceofmotions.Provisionsshouldbemadeforadequateconditionsforseeing.Goodilluminationisthefirstrequirementforsatisfactoryvisualperception.(

Lightofproperintensityforthetask.LightofpropercolourandwithoutglareLightocomingfromtheright(notrightside)directionsothatnokeyworkpositions

arehidden.Theheightoftheworkingplaceandthechairshouldpreferablybearrangedsothatalternatesittingandstandingatworkareeasilypossible.

Achairofthetypeandheighttopermitgoodpostureshouldbeprovidedforeveryworker.Footrest–anadjustablefootrestshouldbeprovidedwhereveritispossible.Itmaybeattachedtothechair,floororworktablemaybeused.Armrest–armrestaremosteffectiveonworkthatrequireslittlemovementoftheforearms,withthehandsworkingatapproximatelythesameposition.Thearmrestmustnotinterferewiththenormalworkingofthearmsandhands.

PrinciplesofMotionEconomyrelatedtothedesignoftoolsandequipment

Thehandsshouldberelievedofallworkthatcanbedonemoreadvantageouslybythetoolsi.e.footoperateddevices,scissorsetc.Twoormoretoolsmustbecombinedwheneveritispossible.Itisquickertoturnasmalltwoendedtoolendthanitistolayonetooldownandpickanother.Toolsandmaterialsshouldbeprepositionedwheneverpossible.Forprepositioningaholderintheformofsocket,compartment,bracket,orhangershouldbeprovided.Whereeachfingerperformssomespecificmovement,suchasintypewriting,theloadshouldbedistributedinaccordancewiththeinherentcapacitiesofthefingers.Levers,handwheelsandothercontrolsshouldbelocatedinsuchpositionthattheoperatorcanmanipulatethemwiththeleastchangeinbodypositionandwiththegreatestspeedandease.

LocationofmaterialsTheworkstudyofficershouldconsideranumberofpointsbeforedecidingwherethepartsshouldbeplaced,theyinclude

Garmentpartsshouldbelocatedinthenormalworkingarea,ifpossible,becauseitiseasiertohandleandseethingswithinthisarea.Anyholdersorshelvesshouldbearrangedsothatthecontentsareusedinthecorrectsequenceandconsidertoplacethemintheextendedworkareatothemaximumpossible.

Manysewingmachineinourfactoriesareattachedtoastandardtablesuppliedbymanufacturer,butthereareseveralthingswhichcanbedonetomakeworkeasier.Suchas,

Extensionstothetable(atfront,sides,rearorinfrontandsideetc.)theseareextremelyusefulwhenhavingtohandlelargeorunusualshapedgarmentparts.Shelves(forsmallparts,forlargeparts,forlabelsetc.)thesecanbeusedforstackinggarmentpartsandtheyareineasyreachforpickup.Thismeanstheoperatordoesn’thavetosearchforparts.

Cutouts(atthesideofthetable,atrear,nearneedleetc.)canbeusedeithertoeasethedisposalofthegarmentaftersewing,suchasacutoutatthereartable,ortopositionthepartsoftheneedleeasier,suchasacutoutinfrontoftheneedle.

HoldersandClampsforextremelysmallgarmentpartsorlabelsandclampsforthemaingarmentpartsareusefulastheyeliminatetheoperatorhavingtolocateparts,sincetheyareallheldinoneposition.

Overheadconveyorsorrails.Thesetypeofsystemscanbeusedforlargeormediumsizedgarment,especiallywherethereisaneedtocontroltheworkflow.Theclampsmayslidealongtherailormaybefittedwithwheels,andtherailitselfcanbefrommachine

heightupwards,accordingtothelengthofthegarment.Thegarmentscanbesinglesorinsmallbundlesandtheymayeitherstayintheclampwhilesewingorberemovedforeachoperation.

Line,Capacity,WIP,Scheduling,LeadTime,LoadLevelling,Bottleneck,Reportingsequencing

9ProductionPlanning

Productionisthenucleusorthecenteroftheentireorganisationsbusinessoperations.Productionplanningcomprisetheplanning,routing,dispatching,andfollowupfunctionsinthemanufacturingprocesssothatthemovementofmaterial,performanceofmachinesandoperationsofthelabour,aredirectedastoquantity,quality,time,andplace.

Productionplanningistheessentialprerequisitestoproductioncontrol.Itinvolvesmanagementdecisionsontheresourcesthatthefirmwillrequireforitsmanufacturingoperationsandtheselectionofthoseresourcestoproducethedesiredgoodsatappropriatetimeandattheleastpossiblecost.

“Productionplanningisthetechniqueofforeseeingorpicturingahead,everystepinalongseriesofseparateoperations,eachsteptobetakenintherightplace,oftherightdegreeandattherighttime,andeachoperationtobedoneatmaximumefficiency.”

TheplanningprocessinclothingmanufactureThebasicprocessincludesthefollowingstages:1.Receivetheorder2.Plantocheckifthereisavailablecapacityinsewingtoachievethedeliverydaterequired3.Plantochecktheavailablecapacityinnon-sewingareas(cut,embroidery;print,washandpack)4.Plantochecksufficientleadtimetoorderandreceivefabric,trims,approvesample,carryoutlabtestsetc.5.Confirmdeliverydatetocustomerandreservecapacity6.Communicateplantoalldepartments7.Monitorprogressagainstplan8.Re-planasrequiredandreturntoPoint5.Inanidealworld,thiscyclewouldbecarriedoutinasystematicway.Noplaniseverperfect,butallthatwehavelearnedabouttotalqualitymanagementremindsusthatwemustaimattheidealratherthansettlefor‘AcceptableQualityLevels’thathaveabuilt-infailurerate.Althoughthefirstpriorityisthecustomerdeliverydate,thefactorymustalsoconsiderthebestplacetomakeeachproduct,takingintoaccountbothskillandmachineconstraints.Productionefficiencydependsuponthis.Intheclothingindustry,planningwilltypicallyfocusonsewing,asitcanaccountforupto80%oftheskillandresourcesrequired.However,thecapacityconstraintsofsupportingareasalsohavetobeassessed.Inparticular,thepre-productioneventsmustbeplannedtoensurethatproductionbeginsonschedule.Therequirementandfunctionsofproductionplanningisapparelindustrycanbedescribesas,JoborTaskScheduling:-Preparationoftimeandactioncalendarforeachorderfromorderreceivingtoshipment.Thejobschedulecontainslistoftaskstobeprocessedforthestyles.Against

eachtasksplannermentionswhentostartataskandwhatisdeadlineforthattask.Nameofresponsibleperson(department)forthejobisbeinglisted.Forexample,schedulingplannedcutdate(PCD),lineloadingdateetc.MaterialResourcePlanning(Inventory):PreparationofMaterialrequirementsheetaccordingtosampleproductandbuyerspecificationsheet.Consumptionofmaterial(fabric,thread,button,andtwilltape)iscalculatedandestimatedcostofeachmaterial.Loadingproduction:Plannerdefineswhichstyletobeloadedtotheproductionlineandhowmuchquantitytobeloaded.

Processselection&planning:Processesneededtocompleteanordervarystyletostyle.Accordingtotheorder(customer)requirementPPCdepartmentselectprocessesfortheorders.Sometimeextraprocessesareeliminatedtoreducecostofproduction.

Facilitylocation:Whereacompanyhasmultiplefactories(facilities)forproductionandfactoriesaresetforspecificproduct,plannerneedtoidentifywhichfacilitywillbemostsuitableforneworders.Sometimestheremaybeacapacityshortageinafactory,inthatcaseplannerneedtodecidewhichfacilitywillselectedforthatorders.

Estimatingquantityandcostsofproduction:Plannerestimatedailyproduction(units)accordingtothestylesworkcontent.Withtheestimatedproductionfigure,productionrunsandmanpowerinvolvementplanneralsoestimateproductioncostperpieces.

Capacityplanning:PPCdepartmentplaysamajorroleduringorderbooking.Theydecide(suggest)howmuchordertheyshouldacceptaccordingtotheirproductioncapacity.Allocatingoftotalcapacityordecidinghowmuchcapacitytobeusedforanorderoutoftotalfactorycapacity.Regularlyupdatingfactoriescurrentcapacity(productioncapacity).

Lineplanning:Preparingdetailedlineplanningwithdailyproductiontargetfortheproductionline.MostcaseslineplanningismadeafterdiscussingwithproductionteamandIndustrialengineers.

Followupandexecution:WhateverplanismadeisexecutedbyPPCdepartment.PPCdepartmentkeepscloselookwhethereverythingisprogressingaccordingtheplan.Chasingotherdepartmentheadsondailybasistokeepplanontrack.TheyupdateorderwisecompletedtasksontheTime&actionCalendar.Whentheyfoundsomethingisgoingtobelatetheyexpediteandcreateanalarmaboutthedelay.

RoleoftheSAMSAMvalueofagarmentisdefinedashowmuchtimeitwouldtaketocompleteagarmentinsewing.Thisisalsoknownasgarmentworkcontentandstandardminutes.

LineCapacityCalculationThescientificmethodofcalculatingproductioncapacityofaline(inproductionpiecesperday)istousestandardtime(SAM)ofagarment.So,todetermineproductioncapacityofaline(forspecificproducts)inpiecesyouneedtoknowgarmentSAM.

LeadTimeCalculationBasedontheproductioncapacity,orderallocationisdonefordifferentlines.Aplanningguyalsoneedtocalculatehowlongastylewouldruninalineifloadedinasingleline.If

youneedtocompletetheorderinlesstime,calculatehowmanylinestobeconsideredforanorder.

OrderbookingDuringorderbooking,youneedtoconsidercapacityavailabilityinacertainperiod.InsuchcasesyoucanusehowmanyminutesyouneedtomakethenewordersusinggarmentSAMvalueandcomparethesamewithhowmanyproductionminutesareavailableinyourfactoryforthedefinedperiod.

ProcessSchedulingTimeandactioncalendarorproductionprocessschedulingofeachorderisdonebyplanningdepartment.Againtoschedulealistoftasks,youneedtoknowcapacityofeachprocessperday(orapredefinedperiod).Basedonthecapacityofeachprocessyouallocateno.ofdaysfortheprocess.Likeforsewingdepartment,youdeterminesewingcapacityofyourline(ormultiplelines)andaccordingtothatyousethowmanydaystobegiventosewingdepartmentforproduction.

OrderExecutionandProductionMonitoringStandardminuteshelpplannerstosettargetforsewinglines.Mutuallyagreedandcalculatedtargetgiventolinesupervisors.Ondailybasiswhenyoucheckproductionstatusyoucancompareactualproductionwithtargetproduction.Incaseproductionisgettingdelayedyoucanpushproductionteambasedongiventarget.

LaborCostEstimationOnemostimportanttaskislaborcostestimationofaspecificorder.Toestimatehowmuchlaborcosttobeconsideredforanorder(style),youcan’tmakelaborcostingwithouthavinggarmentSAMvalue.

AlltheabovesixpointsisprovingthatgarmentSAMplaysabigroleinproductionplanningandcontrollingfunctioningarmentindustry.LinePlanning

Lineplanningisschedulingandallocatingoforderstoproductionlinesaccordingtoproductsetting(productisbeingmadeintheline)andduedatesofproductioncompletion.Alineplandefineswhenastyleisgoingtobeloadedtotheline,howmanypiecestobeexpected(target)fromthelineandwhenordertobecompleted.Duringbookingordersorallocatingorderstotheproductionline,plannersmustcheckwhatisrunningonthelineandhowmanydaysitwilltaketocompletetherunningstyle.

BenefitofLineplanning:Ithelpsproductionmanageraswellaslinesupervisorwithinformationsuchaswhatisthedailyproductiontargetforline.Theysettheirline(machinesandmanpower)accordingly.Lineplanalsoprovidesinformationsuchashowmanydaysstylewould

run,whatisthenextstylegoingtobeloaded?

Lineplanningcanbepreparedtomostalltheorders.Thisiseasytocomparetheavailableslotstotakenewordersornot.Alsoitcangivethecomparisonwithachievedproductionandrequirementofadditionalresourcesofproductionimprovementlikeovertimeoroutsourcingmayberequiredincaseoflowproductionhappensaday.

Capacityplanning

Planningincludesdeterminationofhowmuchlingrangeproductioncapacityisneeded,whenadditionalcapacityisneeded,whereproductionfacilitiesshouldbelocatedandthe

layoutandcharacteristicsofthefacilities.

Capacityisthemaximumproductionrateoffacilityorafirm.Itisusuallyexpressedasvolumeofoutputperperiodoftime.ThiswasexplainedinearlierchaptersCapacityindicatestheabilityofafirmtomeetcustomerdemand.Operationsmanagersareconcernedwithcapacitybecause,a)Theywantsufficientcapacitytomeetcustomerdemandintime.b)Capacityaffectscostefficiencyofoperations,theeaseordifficultyofschedulingoutputandthecostofmaintainingthefacility.c)Capacityrequiresandinvestmentofcapital

CapacityPlanningisnecessarywhenanorganisationdecidestoincreaseitsproductionorintroduceanewproduct.Oncecapacityisevaluatedandaneedforneworexpandedfacilitiesaredetermined,decisionsregardingfacilitylocationandprocesstechnologyselectionaretaken.

CapacityrequirementPlanning(CRP)

CapacityrequirementplanningisthetechniquefordeterminingwhatlabourandequipmentcapacitiesareneededtomeettheproductionobjectivessymbolizedinTheMasterProductionSchedule(MPS)andtheMaterialRequirementPlanning(MRP-I).TheCRPandMRP-Iareestablishedspecifywhatmaterialsandcapacitiesareneededandwhentheyareneeded.

EnditemrequirementsarisingfromtheaggregateplanandMPS(masterProductionSchedule)areexplodedintotentativeplannedorderforcomponentsbytheMRPsystem.TheCRPsystemconvertstheseordersintostandardlabourandmachinehourofloadontheappropriateworkersandonthemachinesasidentifiedfromtheworkcentersstatusandshoproutingfiles.

Theoutputisaloadprojectionreportworkcenterwise.Iftheworkcentercapacitiesareadequate,theplannedorderreleasesareverifiedfortheMRPsystemandreleaseordersbecomepurchaseandshoporders.Workleadersarealsousedforcontrollinginputoroutput.Iftheinitialloadprojectionreportsrevealsinadequacyofcapacityinanyworkcenter,eitherthecapacitymustbeincreased(byusingovertimeorsubcontracting)orthemasterproductionschedulemustberevised.

Inputsneededare,

PlannedordersandreleasedordersfromMRPLoadinginformationfromtheworkcenterstatusRoutinginformation(wheretheworkisdoingtobedone)Changes,whichmodifycapacity,givealternativeroutingoralteredplannedorders.

Aroutingisthepaththatworkfollowsfromworkcentertoworkcenterasitiscompleted.Routingisspecifiedonaroutesheetor,inacomputer-basedsystem,inaroutefile.Aroutingfileshouldexistforeverycomponentmanufacturedandcontainthefollowinginformation:(Operationstobeperformed,Sequenceofoperations,Workcenterstobeused,possiblealternateworkcenters,Toolingneededateachoperation,Standardtimes:setuptimesandruntimesperpiece.)

Machinerequirement.

Inamanufacturingconcern,substantialpartofthefinancialresourcesareinvestedintheplant,machineandequipment.Itissameinthecaseofapparelindustrytoo.Thereturnoftheseinvestmentscanbemaximizedby

1.Makingtheoptimuminvestmentintheplantandmachines,and2.Bymakingtheoptimumutilizationoftheinstalledproductioncapacity.Theissueofmachinerequirementisdealtwiththissession,andthelinebalancingconcernsthesecondpart.Machinerequirementdecidesthedesirableinvestmentinplantandmachines.Machinecapacityisgenerallyexpressedintermsofmachinehour.Letusreducetheformulato,whereST=SAM/60

Letusworkoutwithanexample,Ajobistobeperformed,withthefollowingdata,findthenumberofmachinesrequired?

SAMperjobfortheoperationMaximumcapacityororderquantityofjobStandardcapacityofamachinepermonthAverageutilizationofthemachinecapacity=6min=70,000piecespermonth=2,000piecespermonth.=90%

Then,Aspertheformula,ST=6/60=0.1

Totalmachinerequired=3.88machines,asthemachineisanindivisibleeconomicunit,=4

Or

Intheaboveexample,Target=70,000piecesinonemonthSMV=6minutesCapacityofam/c=2,000pcspermonthMachineTimeavailable=2000x90%=1800Hence,

==3.88=4machines.LineBalancing.Alineisdefinedasagroupofoperatorsunderthecontrolofoneproductionsupervisorordoingsamevolumeoftarget.

Linebalancingistheequaldistributionofworkamongtheworkersofaparticularline,onthebasisoftimetakenofeachoperation.Linebalancingisavitalkeyintheefficientrunningofaline.Theobjectoftheprocessisto“balancetheworkload”ofeachoperationtomakesurethattheflowofworkissmooth,thatnobottlenecksarecreatedandtheoperatorsareabletoworkatpeakperformancethroughouttheday.Thisprocessisintendedtoreducewaitingtimetoaminimumandtherebyreducingidletime.Orinfact,withtheuseofsomeworkinprogresstoeliminatewaitingtimecompletely.

Themethodoflinebalancingcanvaryfromfactorytofactoryanddependonthetypeofgarmentsmanufacturedbutinanyinstance,linebalancingconcernsitselfwithtwodistinctapplications“Settingup”alineand“Runningaline”

Theproblemoflinebalancingarisesdueto,1.Thefinishedgarmentsistheresultofmaysequentialoperations2.Theproductioncapacityofeachmachineisnotidentical

Thetechniqueoflinebalancingreducestheidletimeoftheinstalledcapacityand

facilitatestheintensiveuseofproductioncapacity.Sometimeslinebalancingcanhelpinresourceplanningtocalculatehowmanymachinesarerequiredforabetterline.Etc.letusworkwithabasicexample.

OperationAhas100piecesperHr.productioninamachineOperationBhas50piecesperHr.Operationchas25piecesperHr.TheoperationsequenceisABCNowifonlyonemachineisprovidedfortheprocesspassingsequentialthroughthemachinesA,BandCthen,themachineproductioninthelinewillbedecidedonthebasisofmachinewiththeleastproductioncapacitythatismachineChaving25piecesperhour.Hencethelineoutputwillalsobe25.TheproductioncapacityofmachinesAandBwillbeconfinedtotheproductionof25unitsperhouronly.SoineachhourmachineAandBwillremainidlefor45and30minutesrespectively.ItshouldbeReceiving

MachineA(100-75)=25MachineB(100-50)=50MachineC=25Shipping25

notedthatintheprocesslayoutsuchidletimeorslackscanbeminimizedthoughproper“routing”andschedulingofotheroperations.Howeverasgarmentisworkingasaproductlayoutstructure,duetothelineararrangementofthemachines,theutilizationofsuchidlecapacitywouldberelativelydifficult.Theconceptoflinebalancingistosolvetheproblem.Alinebalancedmodeofthesameissueare,Letus

compareboththesituations,

Sitaution1NoofOpTheoryActualTotalMachines=3Capacity/M/c1110025capacity/M/c215025capacitu/M/c312525TotalSAM2.92capacity/Hr61.71Actualoutput2525Lineefficiency40.51idletime75Min

Situation2NoofOpTheoryActualTotalMachines=7Capacity/M/c11100100capacity/M/c2250100capacitu/M/c3425100TotalSAM2.92capacity/Hr144.00Actualoutput

100100Lineefficiency69.44

SettingUpaLine.Theactualproductionofthelinewillbedecidedonthebasisofthemachinewiththemaximumproductioncapacity.Theproductioncapacityoftheothermachinesinthelinewillbeadjustedthroughtheincreaseinthenumberofmachines.Wewilleitherhowmanymachinesarerequiredtoachievetherequiredrateofproductionorhowmanygarmentscanbeproducedbyagivennumberofoperators.Eithertheway,weareinneedofthefollowingdatatodothebalancing.

a)NumberofOperatorsinlineb)Listofoperationsinvolvedinmakingthespecificgarmentc)Thestandardtimeforeachoperationd)Outputrequiredfromthegivenlinee)Typeofmachines,itsattachments,workaids,threadtype,colouretc.alsoinneed.f)Operatorskill(crosstrainedoperatorsetc.)&SkillMatrixg)Needleandseamtypesetc.h)Operatormovementsbetweenmachines.

Methodoflinebalancing1.AdduptheoperationTimestothesum(wholegarmentSAM)2.Establishwhatpercentageeachoperationisofthetotaltime3.Workouttheoreticalbalance,byusingeachoperation’spercentageofthetotalnumberofoperatorsontheline.4.Roundthetheoreticalbalancetonearthehalfofanoperator,eitherupordown.5.Whereyouhave“half”operatorcombineitwithsimilarequipmenttoget“full”operator.6.Ifyouhavean“Odd”halfoperator,thisshouldberoundedup(theoperatorcouldbeusedtohelptobalancethelineinsituationssuchasabsenteeism,machinetroubleetc.)7.Calculatethenumberofgarmentsthatwouldbeproducedperhouroneachoperation.(numberofoperatorsmultipliedwith60anddividebythetotalSMV)8.Listthetypeofequipmentrequiredforeachoperation.9.ListtheOperatortokennumberforthespecificoperator(thisdoneasperskillmatrixforarunningline,forbetterproductivityandutilizationonly.)10.Calculatetheoreticaloutput.(numberofoperatorsx60dividedbySMA)11.Calculatethebalanceefficiency.(lowestoutputdividedbytheoreticaloutput)12.Calculatethelineforecast.(theoreticaloutputxefficiency)However,inrealitytheproblemisnotsimple.Themainproblemarisingoutofsuchsimplifiedlinebalancingisthedisposalofthelargevolumeofproduction.Insuchsituation,thesolutionissoughtwiththehelpofcost-benefitanalysis.Ifthecostofoverprotectionexceedsthecostofidlecapacityintheunbalancedline,thenattemptsaremadetosolvetheprobleminsomeothermanner.Theofidlecapacityintheunbalancedlinecanbesolvedinsomeothermannerlike,Anotherproductlineenablingtheuseofidlecapacityofthefirstlinecouldberunclosetoit.However,sometimessuchasolutionmaycreatemorecomplexissuesthatitcansolve.Bytransferringtheworkelementsfromoverloadedmachinestosomeothermachinessomewhereelseintheline.Suchsolutionmaycausemorehandlingcostandincreasedprocessingtime.Formulastoremember

Anexamplelinebalancingsheetisshownbelow,pleasereadwiththeabovecalculationstepsinmind.SNOperationSMVM/c%ofTheoryActualPcs/ActualSMVoperatorsOpertsHroutput

1FlatLockSleeves2LipElastictoNeck3ZZLace4JoinShoulder5InsertSleeve6CloseSides7FlatlockHem8Bartack9Labels0.7683NFL13.680.961.006256250.3042NCS5.410.380.507896250.6082NFL10.830.761.007896250.4613TO/L8.210.570.505215210.8623TO/L15.351.071.005575210.9583TO/L17.061.191.507525210.8042NF/L14.321.001.005975210.566Bartack10.080.711.008485210.295.070.360.50842521

TOTALSMV5.6167.008.00

TargetProductionMinutesavailableTotalavailablemanpowerSalaryofoperator598Noofworkstations7480NoofIndirectNVA07Plannedoutput/hr.684INR125Actualoutput/hr.521

Targetproduction@75%efficiency449Balancingefficiency76.1Totalrequiredmanpower8.00Totalm/cRequired(…)Totalm/cRequired(SNLS)Totalm/cRequired(.)Totalm/cRequired(……..)Totalm/cRequired(….)

Theproblemsoflinebalancingshouldbesolvedonthebasisofcost-benefitanalysisoftheincrementalproblem.TechniqueslikeLinearprogramming,dynamicprogramming,PERT,CPMetc.areemployedintheanalysis.Themaximumeconomicbenefityieldingsolutionsareadopted.

RunningaLineWhenrunningaline,thesupervisorwillbeconcernedwitheliminatinganyproblemswhicharisethroughouttheday.Asevenwiththemostcarefullyplannedstyleandbestorganizedproductionfloor,itisimpossibletobalancetheproductionfromoperatortooperator,sothatitremainsperfectthroughouttheday.Duetofactorslikemachinebreakdown,absenteeism,differentperformancelevelsbetweenoperators.Thesupervisorwillconstantlyhavetoreassessthebalancebetweenoperations.Therearecertainfactorswhichthesupervisorcanlookfortohelpthebalancingoftheline.Theyare,

ThereshouldbeareasonablelevelofworkinProgress.Arecommendedlevelisbetween30minto1hr.betweenoperations.Anythingbelow30minuteswillnotgivethesupervisorsufficienttimetoreacttoabreakdown.Anythingabove60minutesupplyis

unnecessary.

Workinprogressshouldalwaysbekeptingoodorderandfullview

Haveanumberofadditionalmachiniststrainedonmanyoperationssothattheycanbeusedwherenecessarytocoverforabsenteeism.Thereforeifabsenteeismis5%,asquadofskilledoperatorswouldberequiredtocoverthisamount.

Spaceshouldbemadeavailablewithinthelineforsparemachinesincaseofabreakdown.Ensurethatthemechanicskeepthemachineregularlyserviced.Ifabottleneckkeepsoccurringataparticularplaceintheline,improvethemethodtoeliminatethebottleneck.Itismostimportanttoestablishwherethispointisontheline.Ifnecessaryrecheckthelinebalancing.Supervisorsmustknowthecapabilitiesandskillsoftheoperatorsundertheircontrol.Supervisorsmustlearnthattheamountofworkwaitingforeachoperationwillincreaseordecreaseoveraperiodoftime,andmustplanwhentotakeappropriateaction.Thesupervisorshouldhaveinmindaminimumandmaximumnumberofbundlesthatshouldbeateachoperation,andwhatactiontotakeiftheleveldropsorrises.Supervisioncouldcarryoutbalancingdutyregularlyattwohourintervals.Checkingeveryoperationonthelinetoensurethattheworkinprogressleveliswithinthecorrectlimits.Balancingdutiesshouldbecarriedoutontimeirrespectiveofwhatelsethesupervisorisdoing.Thesupervisorshouldbeabletomakeuphis/hermindaboutwhattodoifthelevelsarenotcorrect,andnothavetowaitfortheApparelengineertomakethedecisionforhim.

WorkInProgress(WIP)Workinprogress(WIP)referstomaterialthathasenteredtheproductionprocessbutisnotyetafinishedproduct.Workinprogress(WIP)thereforereferstoallmaterialsandpartlyfinishedproductsthatareatvariousstagesoftheproductionprocess.WIPexcludesinventoryofrawmaterialsatthestartoftheproductioncycleandfinishedproductsinventoryattheendoftheproductioncycle.WorkInProgress(WIP)isahazardwellknowntotheapparelmanufacturingfraternity.Expressedindays,itismostcommonlymeasuredbydividingthetotalWIPinpiecesbytheaverageproductiontargetforaday.“MostfactorieshavezerocontrolonWIP.TheclassicAmericanconceptof‘CutandDump’whichadvocatesthatoncedumpedonthefloor,therewillbepressureontheworkerastheyliketoseeamountainofgoodsinandaroundhim/her.Slowlythegoodswillkeeponmoving.ThisWIPbuild-upactuallybeginstohurtduringstylechangeoverswhenfor2to4daysthelinesarerunningandthefirstpieceisstillnotout,”sharesNimishDave,Director,TheIdeaSmith.ThecompanyhasrecentlyaccomplishedaWIPmanagementprojectatIndo-BritishGarments,popularlyknownastheuniformsourcing/manufacturingwingofsecuritysolutionsproviderG4S.Whentheprojectcommenced,everyworkstationhad70pcs,2daysofWIPinthelineandachangeovertimeof2days.Now,theWIPhasbeenreducedto1day,thebundlesizeforeveryworkstationto10days(theteamisaimingatbringingthisfiguredownto4daysandthestylechangeovertimehasbeenreducedto1to3hours.TheendingbalanceintheWIPaccountisthevalueofpartiallycompletedinventoryasoftheenddateofthereportingperiod.Businessesthatmaintainaperpetualinventoryalways

knowthecurrentvalueofWIP,butbusinessesthatemploytheperiodicinventorymethod,bytakingphysicalcountsoffinishedgoods,orcanuseaformulatodetermineperiod-endingWIP.

Letusdowithanexample,

TheSAMofoperation=0.54Setbundlesize=56piecesOperatorsinLine=12

WIPoftheoperator=56x0.54x12=30minutesTotalBufferpieces=56x12=672piecesWeshouldunderstandthat,WIPisnormallyexpressedinformoftimeonly.Fromtheaboveexample,ifthereisnofeedhashappenedtotheoperatorfromhisfeederduemachinetroubleorelse,eventhoughhehassufficientbufferpiecesfor30minutesworking.Thequantityofpiecesofrawmaterialsrequiredtokeeptheoperatorworkforthatmuchtimeiscalledasthebufferquantity.

Fromtheabovelinebalancingexample,letusfindouthowmuchshouldbethebundlequantityrequiredforeachoperatorasWIPandtotalWIPrequiredfortheline.SNOperationSMV

1FlatLockSleeves0.772LipElastictoNeck0.303ZZLace0.614JoinShoulder0.465InsertSleeve0.866CloseSides0.967FlatlockHem0.808Bartack0.579Labels0.2910

Sheet1WIPM/cOperatorPlannedPcs/Hrtodo94reqW/S2NFL1.31.5117362NCS0.50.599142NFL1.0199293TO/L0.8199223TO/L1.41.599413TO/L1.61.59445

2NF/L1.31.59438Bartack0.919427SNLS0.50.59414

TOTALSMV5.62

TargetProduction101Minutesavailable60Totalavailablemanpower10.0WIPPlanned(min)30.00Targetproduction@75%efficiency

9.410.09426447Noofworkstations10ActualWIPinLine(min)47Plannedoutput/hrActualoutput/hr94Balancingefficiency93

ThisshowsonlyatheoreticalWIPintheline,butinactualitmaybedifferent,littlemoreinquantitybecauseoftheunityofbundlesizes.Thebundlesizesaregenerallyaccordingtothecutorderplan,means,inmostcases,cutorderplanispreparedafterthepreparation

oftheproductionschedulesonly,hencethecutorderplanispreparesaccordingtotherequirementsoftheWIPalso.IntheabovesituationwehaveaplannedWIPof30minbutinactualwhilewesee,wearehavingatheoreticalWIPof47min.WIPcanbecalculatedinmostdepartmentsbyasimplemethods,

CuttingWIP:-WhenonecalculatescuttingroomWIPonlystockcutpiecesisconsideredascuttingWIP.FabricthosearelayeredontableorreceivedfromfabricstoreforcuttingisnotconsideredasWIP.SewingSectionWIP:-WIPlevelofsewingsectioncanbecalculatedforaline,forafloororWIPbetweentwooperations.YouhavetousespecificformulaforwhatyouarecalculatingWIPlevel.FinishingRoomWIP:ThereareprimarilythreereasonsformaintainingWIPbetweenanytwosewingoperators(forbothPBUandUPSsystem):

TobalancetheunequalSAMbetweentwooperationsTocoverabsenteeismTocovermachinebreakdown

ItcanbededucedfromtheabovefactorsthatafactorywithheavyabsenteeismandveryoldmachineswillkeepmoreWIPthanafactorywithlesserabsenteeismandnewermachines.Further,iftheSAMofdifferentoperationsinthestyleisclosertopitchtime,thenbalanceefficiencywillbehigherandlesserWIPcanbemaintainedbetweenanytwooperations.Theeffectofabovethreefactorscanbeminimizedbuttheneteffectwillstillremain,andhencetheWIP.

OptimumWIPlevel

ThereisnomagicformulatocalculateoptimumWIPlevelforasewingline.OutofthethreeabovereasonsformaintainingWIP,whilethefirstreasoniscontrollableandcanbepredictedandtheWIPcalculated,thelasttworeasonsareunpredictableandthecalculationisbasedonlyonhistoricaldata.

Forexample,ifSAMforoperation‘A’is0.8min.andoperation‘B’is0.9min.,then‘A’isgoingtoproduce75piecesperhourandoperation‘B’willproduce66piecesperhour.If‘B’isfeeding‘A’,theneveryhourtherewillbe9piecesofshortfallandunlessWIPismaintainedbetweenthem,‘A’cannotworktoitsfullpotential.Ifwemaintainaround72piecesofWIPin-between,thenbothoperatorscanworktotheirfullpotentialuninterruptedlyfor8hours(72dividedby9=8)

SchedulingOrders

Sofarwehaveassumedthatweknowwhenanordershouldberunononeworkcenter.Mostordersareprocessedacrossanumberofworkcenters,anditisnecessarytocalculatewhenordersmustbestartedandcompletedoneachworkcentersothefinalduedatecanbemet.Thisprocessiscalledscheduling.InthenintheditionoftheAPICSDictionary,schedulingisdefinedas“atimetableforplannedoccurrences.”

a.Backscheduling.Theusualprocessistostartwiththeduedateand,usingtheleadtimestoworkbacktofindthestartdateforeachoperation.Thisprocessiscalledbackscheduling.Toschedule,

weneedtoknowforeachorder:

Thequantityandduedate.SequenceofoperationsandworkcentersneededSetupandruntimesforeachoperation.Queue,wait,andmovetimes.Workcentercapacityavailable(ratedordemonstrated).Theinformationneededisobtainedfromthefollowing:

Orderfile:-containingQuantitiesandduedates.Routefile:describingSequenceofoperations,workcentersneeded,setuptime,andruntime.Workcenterfile:-statusofQueue,move,andwaittimesandworkcentercapacity.

Theprocessisasfollows:Foreachworkorder,calculatethecapacityrequired(time)ateachworkcenter.Startingwiththeduedate,schedulebacktogetthecompletionandstartdatesforeachoperation.ExampleProblem,

Supposethereisanorderfor150ofgearshaftSG123.Theduedateistheday135.Theroutesheet,showninTable1,givesinformationabouttheoperationstobeperformedandthesetupandruntimes.Theworkcenterfile,showninTable2,givesleadtimedataforeachworkcenter.Calculatethestartandfinishdatesforeachoperation.Usethefollowingschedulingrules.

Operationtimesareroundeduptothenearesteighthoursandexpressedasdaysonaone-shiftbasis.Thatis,ifanoperationtakes6.5standardhours,roundituptoeighthours,whichrepresentsoneday.Assumeanorderstartsatthebeginningofthedayandfinishesattheendofaday.Forexample.Ifanorderstartsonday1andisfinishedonday5,ithastakenfivedaystocomplete.Ifmovetimeisoneday,theorderwillbeavailabletothenextworkstationatthestartofday7.

Table1.

OperationWorkS/UTimeNo.Center(standardhours)10121.520140.530170.34030.4550StoresRunTime/pieceOperation(standardhours)

0.2Turnshaft0.25Millslot0.05Drill2holes0.1Grind

InventoryTable2WorkCenter

QueueTime(days)124143175038

AnswerWaitTimeMoveTime(days)(days)11111111

Thecalculationsfortheoperationtimeateachworkcenterareasfollows:Setuptime+runtime=totaltime(standardhours)Operation10:Workcenter12:Operation20:Workcenter14:Operation30:Workcenter17:Operation40:Workcenter03:=1.5+0.20x150=31.5standardhours=4days=0.50+0.25x150=38.0standardhours=5days=0.30+0.05x150=7.8standardhours=1day=0.45+0.10x150=15.45standardhours=2days

Thenextstepistoschedulebackfromtheduedate(day135)togetthecompletionandstartdatesforeachoperation.Todoso,weneedtoknownotonlytheoperationtimesjustcalculated,butalsothequeue,wait,andmovetimes.Theseareintheworkcenterfile.

SupposetheinformationshowninTable2isobtainedfromthesefiles.

Theprocessstartswiththelastoperation.Thegoodsaretobeinthestoresonday135.Ittakesonedaytomovethem,sotheordermustbecompletedonoperation40onday133.Subtractingthewait,queue,andoperationtimes(11days),theordermustbestartedonday123.Withamovetimeofoneday,itmustbecompletedonoperation30onday121.Usingthisprocess,thestartandcompletiondatecanbecalculatedforalloperations.Figure5.8showstheresultingscheduleandgraphbelowshowsthesamethinggraphically.WorkCenter12Operation1014Operation2017Operation3003Operation40

9091101ReleaseDate105112115121125134135

Duedate

MakingthePlan

Sofarwehavediscussedthedataneededforacapacityrequirementsplan,wherethedatacomefrom,andtheschedulingandloadingofshopordersthroughthevariousworkcenters.Thenextstepistocomparetheloadtoavailablecapacitytoseeifthereareimbalancesandifso,tofindpossiblesolutions.

Therearetwowaysofbalancingcapacityavailableandload:altertheload,orchangethecapacityavailable.Alteringtheloadmeansshiftingordersaheadorbacksotheloadisleveled.Ifordersareprocessedonotherworkstations,thescheduleandloadontheotherworkstationshavetobechangedaswell.Itmayalsomeanthatothercomponentsshouldberescheduledandthemasterproductionschedulechanged.ConsiderthebillofmaterialshowninFigure5.10.IfcomponentBistoberescheduledtoalaterdate,thenthepriorityforcomponentCischanged,asisthemasterproductionscheduleforA.Forthesereasons,changingtheloadmaynotbethepreferredcourseofaction.Intheshortrun,capacitycanbeadjusted.Somewaysthatthismaybedoneareasfollows:

Scheduleovertimeorundertime.Thiswillprovidetemporaryandquickreliefforcaseswheretheload/capacityimbalanceisnottoolarge.Adjusttheleveloftheworkforcebyhiringorlayingoffworkers.Theabilitytodosowilldependontheavailabilityoftheskillsrequiredandthetrainingneeded.Thehighertheskilllevelandthelongerthetrainingneeded,themoredifficultitbecomestochangequicklytheleveloftheworkforce.Shiftworkforcefromunderloadedtooverloadedworkcenters.Thisrequiresaflexiblecross-trainedworkforce.Usealternateroutingstoshiftsomeloadtoanotherworkcenter.Oftentheotherworkcenterisnotasefficientastheoriginal.Nevertheless,theimportantthingistomeettheschedule,andthisisavalidwayofdoingso.Subcontractworkwhenmorecapacityisneededorbringinpreviouslysubcontractedworktoincreaserequiredcapacity.Itmaybemorecostlytosubcontractratherthanmaketheitemin-house,butagainitisimportanttomaintaintheschedule.Theresultofcapacityrequirementsplanningshouldbeadetailedworkableplanthatmeetsthepriorityobjectivesandprovidesthecapacitytodoso.Ideally,itwillsatisfythematerialrequirementsplanandallowforadequateutilizationoftheworkforce,machinery,andequipment.Scheduling

Theobjectiveofschedulingistomeetdeliverydatesandtomakethebestuseofmanufacturingresources.Itinvolvesestablishingstartandfinishdatesforeachoperationrequiredtocompleteanitem.Todevelopareliableschedule,theplannermusthaveinformationonrouting,requiredandavailablecapacity,competingjobs,andManufacturingLeadTimes(MLT)ateachworkcenterinvolved.

a.ManufacturingLeadTimeManufacturingleadtimeisthetimenormallyrequiredtoproduceaniteminatypicallotquantity.Typically,MLTconsistsoffiveelements:

1.Queuetime,amountoftimethejobiswaitingataworkcenterbeforeoperationbegins.2.Setuptime,timerequiredtopreparetheworkcenterforoperation.3.Runtime,timeneededtoruntheorderthroughtheoperation.4.Waittime,amountoftimethejobisattheworkcenterbeforebeingmovedtothenextworkcenter.5.Movetime,transittimebetweenworkcenters.

ThetotalmanufacturingleadtimewillbethesumoforderpreparationandreleaseplustheMLTsforeachoperation.Figure6.3showstheelementsmakingupmanufacturingleadtime.Setuptimeandruntimearestraightforward,anddeterminingthemistheresponsibilityoftheindustrialengineeringdepartment.Queue,wait,andmovetimesareunderthecontrolofmanufacturingandPAC.

Thelargestofthefiveelementsisqueuetime.Typically,inanintermittentmanufacturingoperation,itaccountsfor85%—95%ofthetotalleadtime.Productionactivitycontrolisresponsibleformanagingthequeuebyregulatingtheflowofworkintoandoutofworkcenters.Ifthenumberoforderswaitingtobeworkedon(load)isreduced,soisthequeuetime,theleadtime,andwork-in-process.Increasingcapacityalsoreducesqueue.Productionactivitycontrolmustmanageboththeinputoforderstotheproductionprocess

andtheavailablecapacitytocontrolqueueandwork-in-process.

Atermthatiscloselyrelatedtomanufacturingleadtimeiscycletime.ThenintheditionoftheAPICSDictionarydefinescycletimeasthelengthoftimefromwhenmaterialentersaproductionfacilityuntilitexits.Asynonymisthroughputtime.

OrderReleaseQUEUESETUPRUNWAITMOVEQUEUESETUPRUNWAITMOVE

QUEUESETUPRUNWAITMOVEQUEUESETUPRUNWAITMOVE

ExampleProblem

Anorderfor100ofaproductisprocessedonworkcentersAandB.ThesetuptimeonAis30minutes,andruntimeistenminutesperpiece.ThesetuptimeonBis50minutes,andtheruntimeisfiveminutesperpiece.Waittimebetweenthetwooperationsisfourhours.ThemovetimebetweenAandBistenminutes.WaittimeafteroperationBisfourhours,andthemovetimeintostoresis15minutes.Thereisnoqueueateitherworkstation.Calculatethetotalmanufacturingleadtimefortheorder.

AnswerWorkCenterAoperationtime=30+(100x10)=1030minutesWaittimeMovetimefromAtoBWorkCenterBoperationtime=50+(100x5)WaittimeMovetimefromBtostoresTotalmanufacturingleadtime=240minutes=10minutes=550minutes=240minutes=15minutes=2085minutes

LeadTime=34hours,45minutesb.SchedulingTechniques.Therearemanytechniquestoscheduleshopordersthroughaplant,butallofthemrequireanunderstandingofforwardandbackwardschedulingaswellasfiniteandinfiniteloading.

Forwardschedulingassumesthatmaterialprocurementandoperationschedulingforacomponentstartwhentheorderisreceived,whatevertheduedate,andthatoperationsarescheduledforwardfromthisdate.ThefirstlineinFigure6.4illustratesthismethod.Theresultiscompletionbeforetheduedate,whichusuallyresultsinabuildupofinventory.Thismethodisusedtodecidetheearliestdeliverydateforaproduct.

Forwardschedulingisusedtocalculatehowlongitwilltaketocompleteatask.Thetechniqueisusedforpurposessuchasdevelopingpromisedatesforcustomersorfiguringoutwhetheranorderbehindschedulecanbecaughtup.

BackwardschedulingisillustratedbythesecondlineinFigure9abelow.Thelastoperationontheroutingisscheduledfirstandisscheduledforcompletionattheduedate.Previousoperationsarescheduledbackfromthelastoperation.ThisschedulesitemstobeavailableasneededandisthesamelogicasusedintheMRPsystem.Work-in-processinventoryisreduced,butbecausethereislittleslacktimeinthesystem,customerservicemaysuffer.OrderReceived

12345

678DueDate9

ForwardSchedulingMaterial1st2nd3rdOrderedOperationOperationOperationBackwardSchedulingMaterialOrdered1st2ndOperationOperation3rdOperationFig9a

Backwardschedulingisusedtodeterminewhenanordermustbestarted.Backwardschedulingiscommoninindustrybecauseitreducesinventory.

InfiniteloadingisalsoillustratedinFigure9a.Theassumptionismadethattheworkstationsonwhichoperations1,2,and3aredonehavecapacityavailablewhenrequired.Itdoesnotconsidertheexistenceofothershoporderscompetingforcapacityattheseworkcenters.Itassumesinfinitecapacitywillbeavailable.Figure9ashowsaloadprofileforinfinitecapacity.Noticetheoverandunderload.

Finiteloadingassumesthereisadefinedlimittoavailablecapacityatanyworkstation.Ifthereisnotenoughcapacityavailableataworkstationbecauseofothershoporders,theorderhastobescheduledinadifferenttimeperiod.Figure6.6illustratesthecondition

c.OperationOverlappingInoperationoverlapping,thenextoperationisallowedtobeginbeforetheentirelotiscompletedonthepreviousoperation.Thisreducesthetotalmanufacturingleadtimesbecausethesecondoperationstartsbeforethefirstoperationfinishesallthepartsintheorder.Figure6.8showsschematicallyhowitworksandthepotentialreductioninleadtime.Anorderisdividedintoatleasttwolots.WhenthefirstlotiscompletedonoperationA,itistransferredtooperationB.InFigureonright,itisassumedoperationBcannotbesetupuntilthefirstlotisreceived,butthisisnotalwaysthecase.WhileoperationAcontinueswiththesecondlot,operationBstartsonthefirstlot.WhenoperationAfinishesthesecond

lot,itistransferredtooperationB.Ifthelotsaresizedproperly,therewillbenoidletimeatoperationB.Themanufacturingleadtimeisreducedbytheoverlaptimeandtheeliminationofqueuetime.

Operationoverlappingisamethodofexpeditinganorder,buttherearesomecostsinvolved.First,movecostsareincreased,especiallyiftheoverlappedoperationsarenotclosetogether.Second,itmayincreasethequeueandleadtimeforotherorders.Third,itdoesnotincreasecapacitybutpotentiallyreducesitifthesecondoperationisidlewaitingforpartsfromthefirstoperation.Theproblemisdecidingthesizeofthesublot.IftheruntimeperpieceonoperationBisshorterthanthatonA,thefirstbatchmustbelargeenoughtoavoididletimeonoperationB.ExampleProblemRefertothedatagivenintheexampleprobleminthesectiononmanufacturingleadtime.ItisdecidedtooverlapoperationsAandBbysplittingthelotof100intotwolotsof70and30.WaittimebetweenAandBandbetweenBandstoresiseliminated.Themovetimesremainthesame.SetuponoperationBcannotstartuntilthefirstbatcharrives.Calculatethemanufacturingleadtime.Howmuchtimehasbeensaved?

OperationtimeforAforlotof70MovetimebetweenAandBOperationtimeforBforlotof100MovetimefromBtostoresTotalmanufacturingleadtimeTotalTimesaved=2085-1305=30+(70x10)

=50+(100x5)

=1305minutes=780minutes=30minutes=10minutes=550Minutes=15minutes=2hr,45minutes=13hours

d.OperationSplitting

Operationsplittingisasecondmethodofreducingmanufacturingleadtime.Theorderissplitintotwoormorelotsandrunontwoormoremachinessimultaneously.Ifthelotissplitintwo,therun-timecomponentofleadtimeiseffectivelycutinhalf,althoughanadditionalsetupisincurred.Figonrightshowsaschematicofoperationsplitting.Operationsplittingispracticalwhen:

Setuptimeislowcomparedtoruntime.Asuitableworkcenterisidle.Itispossibleforanoperatortorunmorethanonemachineatatime

Thelastconditionoftenexistswhenamachinecyclesthroughitsoperationautomatically,leavingtheoperatortimetosetupanothermachine.Thetimeneededtounloadandloadmustbeshorterthantheruntimeperpiece.Forexample,iftheunload/loadtimewastwominutesandtheruntimewasthreeminutes,theoperatorwouldhavetimetounloadandloadthefirstmachinewhilethesecondwasrunning.

ExampleProblem

Acomponentmadeonaparticularworkcenterhasasetuptimeof100minutesandaruntimeofthreeminutesperpiece.Anorderfor500istobeprocessedontwomachinessimultaneously.Themachinescanbesetupatthesametime.Calculatetheelapsedoperationtime.

Answer

Elapsedoperationtime100+3X250=850minutes=14hoursand10minutesLoadLevelling

LoadprofileswerediscussedinChapter5inthesectiononcapacityrequirementsplanning.Theloadprofileforaworkcenterisconstructedbycalculatingthestandardhoursofoperationforeachorderineachtimeperiodandaddingthemtogetherbytimeperiod.Figure6.10isanexampleofaloadreport.

ThisreporttellsPACwhattheloadisontheworkcenter.Thereisacapacityshortageinweek20of30hours.Thismeanstherewasnopointinreleasingalloftheplannedordersthatweek.Perhapssomecouldbereleasedinweek18or19,andperhapssomeovertimecouldbeworkedtohelpreducethecapacitycrunch.

WorkCenter:10Description:CollarMakingNumberofMachines:3AvailableTime:120hours/weekEfficiency:115%Utilization80%

RatedCapacity:110standardhours/week

WorkcenterloadreportWeek181920212223TotalReleasedLoad105100803000315PlannedLoad608013080350TotalLoad10510014011013080665RatedCapacity110110110110110110660(Over)/UnderCapacity510-300-2030-5

SchedulingBottlenecks

Inintermittentmanufacturing,itisalmostimpossibletobalancetheavailablecapacitiesofthevariousworkstationswiththedemandfortheircapacity.Asaresult,someworkstationsareoverloadedandsomeunderloaded.Theoverloadedworkstationsarecalledbottlenecksand,bydefinition,arethoseworkstationswheretherequiredcapacityisgreaterthantheavailablecapacity.Inthenintheditionoftheirdictionary,APICSdefinesabottleneckas“afacility,function,department,orresourcewhosecapacityisequaltoorlessthanthedemandplaceduponit.”

Throughput.Throughputisthetotalvolumeofproductionpassingthroughafacility.Bottleneckscontrolthethroughputofallproductsprocessedbythem.Ifworkcentersfeedingbottlenecksproducemorethanthebottleneckcanprocess,excesswork-in-processinventoryisbuiltup.Therefore,workshouldbescheduledthroughthebottleneckattherateitcanprocessthework.Workcentersfedbybottleneckshavetheirthroughput

controlledbythebottleneck,andtheirschedulesshouldbedeterminedbythatofthebottleneck.

ExampleProblem

Supposeamanufacturermakeswagonscomposedofaboxbody,ahandleassembly,andtwowheelassemblies.Demandforthewagonsis500aweek.Thewheelassemblycapacityis1200setsaweek,thehandleassemblycapacityis450aweek,andfinalassemblycanproduce550wagonsaweek.

a)Whatisthecapacityofthefactory?b)Whatlimitsthethroughputofthefactory?c)Howmanywheelassembliesshouldbemadeeachweek?d)Whatistheutilizationofthewheelassemblyoperation?e)Whathappensifthewheelassemblyutilizationisincreasedto100%?

Answer

a)450unitsaweek.b)Throughputislimitedbythecapacityofthehandleassemblyoperation.c)900wheelassembliesshouldbemadeeachweek.Thismatchesthecapacityofthehandle

assemblyoperation.d)Utilizationofthewheelassemblyoperationis900±120075%.e)Excessinventorybuildsup.

Somebottleneckprinciples.Sincebottleneckscontrolthethroughputofafacility,someimportantprinciplesshouldbenoted:

1.Utilizationofanon-bottleneckresourceisnotdeterminedbyitspotential,butbyanotherconstraintinthesystem.Inthepreviousexampleproblem,theutilizationofthewheelassemblyoperationwasdeterminedbythehandleassemblyoperation.

2.Usinganon-bottleneck100%ofthetimedoesnotproduce100%utilization.lfthewheelassemblyoperationwasutilized100%ofthetime,itwouldproduce1200setsofwheelsaweek,300setsmorethanneeded.Becauseofthebuildupofinventory,thisoperationwouldeventuallyhavetostop.

3.Thecapacityofthesystemdependsonthecapacityofthebottleneck.Ifthehandleassemblyoperationbreaksdown,thethroughputofthefactoryisreduced.4.Timesavedatanon-bottlenecksavesthesystemnothing.Suppose,inaflashofbrilliance,theindustrialengineeringdepartmentincreasedthecapacityofthewheelassemblyoperationto1500unitsaweek.Thisextracapacitycouldnotbeutilized,andnothingwouldbegained.5.Capacityandprioritymustbeconsideredtogether.Supposethewagonmanufacturermadewagonswithtwostylesofhandles.Duringsetup,nothingisproduced,whichreducesthecapacityofthesystem.Sincehandleassemblyisthebottleneck,everysetupinthisoperationreducesthethroughputofthesystem.Ideally,thecompanywouldrunonestyleofhandleforsixmonths,thenswitchovertothesecondstyle.However,customerswantingthesecondstyleofhandlemightnotbewillingtowaitsixmonths.Acompromise

isneededwherebyrunsareaslongaspossiblebutpriority(demand)issatisfied.6.Loadscan,andshould,besplit.Supposethehandleassemblyoperation(thebottleneck)producesonestyleofhandlefortwoweeks,thenswitchestothesecondstyle.Thebatchsizeis900handles.Ratherthanwaitinguntilthe900areproducedbeforemovingthemtothefinalassemblyarea,themanufacturercanmoveaday’sproduction(90)atatime.Theprocessbatchsizeandthetransferbatchsizearedifferent.Thus,deliverytothefinalassemblyismatchedtousage,andwork-in-processinventoryisreduced.7.Focusshouldbeonbalancingtheflowthroughtheshop.Thekeyisthroughputthatendsupinsales

ManagingbottlenecksSincebottlenecksaresoimportanttothethroughputofasystem,schedulingandcontrollingthemisextremelyimportant.Thefollowingmustbedone;

1.Establishatimebufferbeforeeachbottleneck.Atimebufferisaninventory(queue)placebeforeeachbottleneck.Becauseitisoftheutmostimportancetokeepthebottleneckworking,itmustneverbestarvedformaterial,anditcanbestarvedonlyiftheflowfromfeedingworkstationsisdisrupted.Thetimebuffershouldbeonlyaslongasthetimeofanyexpecteddelaycausedbyfeedingworkstations.Inthisway,thetimebufferensuresthatthebottleneckwillnotbeshutdownforlackofworkandthisqueuewillbeheldatapredeterminedminimumquantity.

2.Controltherateofmaterialfeedingthebottleneck.Abottleneckmustbefedatarateequaltoitscapacitysothetimebufferremainsconstant.Thefirstoperationinthesequenceofoperationsiscalledagateoperation.Thisoperationcontrolstheworkfeedingthebottleneckandmustoperateatarateequaltotheoutputofthebottlenecksothetimebufferqueueismaintained.

3.Doeverythingtoprovidetheneededbottleneckcapacity.Anythingthatincreasesthecapacityofthebottleneckincreasesthecapacityofthesystem.Betteruti-lization,fewersetups,andimprovedmethodstoreducesetupandruntimearesomemethodsforincreasingcapacity.

4.Adjustloads.Thisissimilartoitem3butputsemphasisonreducingtheloadonabottleneckbyusingsuchthingsasusingalternateworkcentersandsubcon-tracting.Thesemaybemorecostlythanusingthebottleneck,bututilizationofnon-bottlenecksandthroughputofthetotalsystemisincreased,resultinginmorecompanysalesandincreasedprofits.

5.Changetheschedule.Dothisasafinalresort,butitisbettertobehonestaboutdeliverypromises.

Oncethebottleneckisscheduledaccordingtoitsavailablecapacityandthemarketdemanditmustsatisfy,thenon-bottleneckresourcescanbescheduled.Whenaworkorderiscompletedatthebottleneck,itcanbescheduledonsubse-quentoperations.

Feedingoperationshavetoprotectthetimebufferbyschedulingbackwardintimefromthebottleneck.Ifthetimebufferissetatfourdays,theoperationimmediatelypre-cedingthebottleneckisscheduledtocompletetherequiredpartsfourdaysbeforetheyarescheduledtorunonthebottleneck.Eachprecedingoperationcanbehack-scheduledinthesamewaysothepartsareavailableasrequiredforthenextoperation.

Anydisturbancesinthefeedingoperationsareabsorbedbythetimebuffer,andthroughputisnotaffected.Also,work-in-processinventoryisreduced.Sincethequeueislimitedtothetimebuffer,leadtimesarereduced.

Implementation

Ordersthathavetooling,material,andcapacityhaveagoodchanceofbeingcompletedontimeandcanbereleasedtotheshopfloor.Otherordersthatdonothaveallofthenecessaryelementsshouldnotbereleasedbecausetheyonlycauseexcesswork-in-processinventoryandmayinterruptworkonordersthatcanbecompleted.TheprocessforreleasinganorderisshowninFigure9e

Implementationisarrivedatbyissuingashopordertomanufacturingauthorizingthemtoproceedwithmakingtheitem.Ashoppacketisusuallycompiledwhichcontainstheshoporderandwhateverotherinformationisneededbymanufacturing.Itmayincludeanyofthefollowing:

Shopordershowingtheshopordernumber,thepartnumber,name,description,andquantity.Engineeringdrawings.Billsofmaterial.Routesheetsshowingtheoperationstobeperformed,equipmentandaccessoriesneeded,materialstouse,andthesetupandruntimes.Materialissueticketsthatauthorizemanufacturingtogettherequiredmaterialfromstores.Thesearealsousedforchargingthematerialagainsttheshoporder.Toolrequisitionsauthorizingmanufacturingtowithdrawnecessarytoolingfromthetoolcrib.Jobticketsforeachoperationtobeperformed.Aswellasauthorizingtheindividualoperationstobeperformed,theyalsocanfunctionaspartofareportingsystem.Theworkercanlogonandoffthejobusingthejobticket,anditthenbecomesarecordofthatoperation.Moveticketsthatauthorizeanddirectthemovementofworkbetweenoperations

ControlFig9e

Onceworkordershavebeenissuedtomanufacturing,theirprogresshastobecontrolled.Tocontrolprogress,performancehastobemeasuredandcomparedtowhatisplanned.Ifwhatisactuallyhappening(whatismeasured)variessignificantlyfromwhatwasplanned,eithertheplanshavetobechangedorcorrectiveactionmustbetakentobringperformancebacktoplan.

Theobjectivesofproductionactivitycontrolaretomeetdeliverydatesandtomakethebestuseofcompanyresources.Tomeetdeliverydates,acompanymustcontroltheprogressofordersontheshopfloor,whichmeanscontrollingtheleadtimefororders.Asdiscussedearlierinthischapter,thelargestcomponentofleadtimeisqueue.Ifqueuecanbecontrolled,deliverydatescanbemet.Chapter1discussedsomecharacteristicsofintermittentoperationsinwhichmanydifferentproductsandorderquantitieshavemanydifferentroutings,eachrequiringdifferentcapacities.inthisenvironment,itisalmostimpossibletobalancetheloadoveralltheworkstations.Queueexistsbecauseofthiserraticinputandoutput.

Tocontrolqueueandmeetdeliverycommitments,productionactivitycontrolmust:

Controltheworkgoingintoandcomingoutofaworkcenter.Thisisgenerallycalledinput/outputcontrol.Setthecorrectpriorityoforderstorunateachworkcenter

Input/outputControl

Productionactivitycontrolmustbalancetheflowofworktoandfromdifferentworkcenters.Thisistoensurequeue,work-in-process,andleadtimesarecontrolled.Theinput/outputcontrolsystemisamethodofmanagingqueuesandwork-in-processleadtimesbymonitoringandcontrollingtheinputto,andoutputfrom,afacility.Itisdesignedtobalancetheinputrateinhourswiththeoutputratesothesewillbecontrolled.

Theinputrateiscontrolledbythereleaseoforderstotheshopfloor.Iftherateofinputisincreased,queue,work-in-process,andleadtimesincrease.Theoutputrateiscontrolledbyincreasingordecreasingthecapacityofaworkcenter.Capacitychangeisaproblemformanufacturing,butitcanbeattainedbyovertimeorunder-time,shiftingworkers,andsoforth.Figure9fshowstheideagraphically

Tocontrolinputandoutput,aplanmustbedevised,alongwithamethodforcomparingwhatactuallyoccursagainstwhatwasplanned.Thisin-formationisshownonaninput/outputreport.Figure6.gisanexampleofsuchareport.Thevaluesareinstandardhours.InputRatecontrolQueue(LocalWIP)

Fig9f

Period12345TotalPlannedInput3832364044190ActualInput3432324240180

Cumulative-4-4-8-6-10-10VariancePlannedInput4040404040200ActualInput3236444436192Cumulative-8-12-8-4-8-8Variance

PlannedBacklog323022181822ActualBacklog323430181620Fig9g

CumulativevarianceCumulativevarianceisthedifferencebetweenthetotalplannedforagivenperiodandtheactualtotalforthatperiod.Itiscalculatedasfollows:Cumulativevariance=previouscumulativevariance+actual—plannedCumulativeinputvarianceweek2=-4+32-32=-4Backlogisthesameasqueueandexpressestheworktobedoneinhours.Itiscalculatedasfollows:

Plannedbacklogforperiod1=previousbacklog+plannedinput—plannedoutput=32+38—40=30hours

Thereportshowstheplanwastomaintainaleveloutputineachperiodandtoreducethequeueandleadtimebytenhours,butinputandoutputwerelowerthanexpected.

Plannedandactualinputsmonitortheflowofworkcomingtotheworkcenter.Plannedandactualoutputsmonitortheperformanceoftheworkcenter.Plannedandactualbacklogsmonitorthequeueandleadtimeperformance.ExampleProblem

Completethefollowinginput/outputreportforweeks1and2.Week12PlannedInput4540ActualInput4246CumulativeVariancePlannedOutput4040ActualOutput4244CumulativeVariancePlannedBacklog30

ActualBacklog30

AnswerCumulativeinputvarianceweek1=42—45=—3Cumulativeinputvarianceweek2=—3+46—40=3Cumulativeoutputvarianceweek1=42—40=2Cumulativeoutputvarianceweek2=2+44—40=6

Plannedbacklogweek1=30+45—40=35Plannedbacklogweek2=35+40—40=35Actualbacklogweek1=30+42—42=30Actualbacklogweek2=30+46—44=32

OperationSequencing

ThenintheditionoftheAPICSDictionarydefinesoperationsequencingasatechniqueforshort-termplanningofactualjobstoberunineachworkcenterbasedoncapacityandpriorities.Priority,inthiscase,isthesequenceinwhichjobsataworkcentershouldheworkedon.

Thematerialrequirementsplanestablishesproperneeddatesandquantities.Overtime,thesedatesandquantitieschangeforavarietyofreasons.Customersmayrequiredifferentdeliveryquantitiesordates.Deliveriesofcomponentparts,eitherfromvendorsorinternally,maynotbemet.Scrap,shortages,andoveragesmayoccur,andsoon.Controlofprioritiesisexercisedthroughdispatching.

Dispatching.

Dispatchingisthefunctionofselectingandsequencingavailablejobstoberunatindividualworkcenters.Thedispatchlististheinstrumentofprioritycontrol.Itisalistingbyoperationofallthejobsavailabletoberunataworkcenterwiththejoblistedinprioritysequence.Itnormallyincludesthefollowinginformationandisupdatedandpublishedatleastdaily:

Plant,department,andworkcenter.Partnumber,shopordernumber,operationnumber,andoperationdescriptionofjobsattheworkcenter.Standardhours.Priorityinformation.Jobscomingtotheworkcenter.

Dispatchingrules.

Therankingofjobsforthedispatchlistiscreatedthroughtheapplicationofpriorityrules.Therearemanyrules,someattemptingtoreducework-in-processinventory,othersattemptingtominimizethenumberoflateordersormaximize

DISPATCHLISTWorkCenter10ShopDate250RatedCapacity16standardhoursperdayOrderPartNoOrderSetupRunTotalQtyLoadOperationDatesNoQtyHrHrHrCompletedRemainingStardFinish12365541001.51516.5753.752492501217345500.53030.5102424925114226875000.27575.2075250259TotalAvailableLoadinStdHrs.102.75JobsComing14577452000.72020.7020.72512531352832201.212.702.7253254TotalFutureLoadinStandardHours23.4Figure9gDispatchlist(basedon2machinesworkingone8-hourshiftperday

Theoutputoftheworkcenter.Noneisperfectorwillsatisfyallobjectives.Somecommonlyusedrulesare,

Firstcome,firstserved(FCFS).Jobsareperformedinthesequenceinwhichtheyarereceived.Thisruleignoresduedatesandprocessingtime.Earliestjobduedate(EDD).Jobsareperformedaccordingtotheirduedates.Duedatesareconsidered,butprocessingtimeisnot.Earliestoperationduedate(ODD).Jobsareperformedaccordingtotheiroperationduedates.Duedatesandprocessingtimearetakenintoaccount.Aswell,theoperationduedateiseasilyunderstoodontheshopfloor.Shortestprocesstime(SPT).Jobsaresequencedaccordingtotheirprocesstime.Thisruleignoresduedates,butitmaximizesthenumberofjobsprocessed.Orderswithlongprocesstimestendtobedelayed.

Figure9hillustrateshowthesesequencingruleswork.Noticethateachruleusuallyproducesadifferentsequence.

Oneotherrulethatshouldbementionediscalledcriticalratio(CR).Thisisanindexoftherelativepriorityofanordertootherordersataworkcenter.Itisbasedontheratiooftimeremainingtoworkremainingandisusuallyexpressedas:

Leadtimeremainingincludesallelementsofmanufacturingleadtimeandexpressestheamountoftimethejobnormallytakestocompletion.

Iftheactualtimeremainingislessthantheleadtimeremaining,itimpliesthereisnotsufficienttimetocompletethejobandthejobisbehindschedule.Similarly,ifleadtimeremainingandactualtimeremainingarethesame,thejobisonschedule.Iftheactualtimeremainingisgreaterthantheleadtimeremaining,

JobProcessArrivalDueTime(days)DateDateOperationSequencingRuleDueDate

A4223245B1224242C5231240D2219243FCFSEDDODDSPT2332413239322124041342421342Fig9h.ApplicationofSequencing

Thejobisaheadofschedule.Iftheactualtimeremainingislessthanone,thejobislatealready.Thefollowingtablesummarizesthesefactsandrelatesthemtothecriticalratio:

CRlessthan1(actualtimelessthanleadtime).Orderisbehindschedule.CRequalto1(actualtimeequaltoleadtime).Orderisonschedule.CRgreaterthan1(actualtimegreaterthanleadtime).Orderisaheadofschedule.CRzeroorless(today’sdategreaterthanduedate).Orderisalreadylate.

Thus,ordersarelistedinorderoftheircriticalratiowiththelowestonefirst.Criticalratioconsidersduedatesandprocesstime.However,itisnoteasilyunderstood.ExampleProblemToday’sdateis175.OrdersA,B,andChavethefollowingduedatesandleadtimeremaining.Calculatetheactualtimeremainingandthecriticalratioforeach.

LeadTimeOrderDueDateRemaining(days)A18520B19520C20520

AnswerOrderAhasaduedateof185,andtodayisday175.Thereare10actualdaysremaining.Sincetheleadtimeremainingis20days,CriticalRatio=(10/20)=0.5Similarly,theactualtimeremainingandthecriticalratiosarecalculatedforordersBandC.Thefollowingtablegivestheresults:

LeadTime.ActualTime.OrderDueDateRemaining(days)Remaining(days)CRA18520100.5B19520201.0C20520301.5

OrderAhaslessactualtimeremainingthanleadtimeremaining,sotheCRislessthan1.Itis,therefore,behindschedule.OrderBhasaCRof1andisexactlyonschedule.Order

ChasaCRof1.5—greaterthan1—andisaheadofschedule.

Dispatchingrulesshouldbesimpletouseandeasytounderstand.Asshownintheprecedingexample,eachruleproducesadifferentsequenceandhasitsownadvantagesanddisadvantages.Whicheverruleisselectedshouldbeconsistentwiththeobjectivesoftheplanningsystem.

ProductionReporting

Productionreportingprovidesfeedbackofwhatisactuallyhappeningontheplantfloor.ItallowsPACtomaintainvalidrecordsofon-handandon-orderbalances,jobstatus,shortages,scrap,materialshortages,andsoon.Productionactivitycontrolneedsthisinformationtoestablishproperprioritiesandtoanswerquestionsregardingdeliveries,shortages,andthestatusoforders.Manufacturingmanagementneedsthisinformationtomakedecisionsaboutplantoperation.Payrollneedsthisinformationtocalculateemployees’pay.

Datamustbecollected,sorted,andreported.Theparticulardatacollecteddependupontheneedsofthevariousdepartments.Themethodsofdatacollectionvary.Sometimestheoperatorreportsthestartandcompletionofanoperation,order,movement,andsoon,usinganon-linesystemdirectlyreportingeventsastheyoccurviadataterminals.Inothercases,theoperator,supervisor,ortimekeeperreportsthisinformationonanoperationreportingformincludedintheshoppacket.Informationaboutinventorywithdrawalsandreceiptsmustbereportedaswell.

Oncethedataarecollected,theymustbesorted,andappropriatereportsproduced.Typesofinformationneededforthevariousreportsinclude:Orderstatus.Weeklyinput/outputbydepartmentorworkcenter.Exceptionreportsonsuchthingsasscrap,rework,andlateshoporders.Inventorystatus.Performancesummariesonorderstatus,workcenteranddepartmentefficiencies,andsoon

Follow-ups.

Here,letuscheeksomekeyinterestingvalueswhichhavetobecheckedinaproductionlinetoverifythesituationineachsection.Thekeyformulasforbetterreferenceonlyarelistedhere,mostarealreadybeenexplainedorwillbeaddedinparticularsections.

MaterialProductivity:Thisisanindicatoroftheoutputorvaluegeneratedperunitofmaterialused.Thisisafundamentalre-examinationofhow,whenandwhymaterialsareused.Thismeasureshowshoweffectivelymaterialisusedthroughthesystem.Anymaterialleftinthefabricstoreisalsoawasteasitwillbedisposedofatamuchcheaperrate.

MarkerEfficiency:Thisistheratiooffabricactuallyusedonthemarkertototalavailablefabric.Markerefficiencyiscalculatedforonemarkeratatimeandcannotbegeneralizedfortheentireorder.ThismetricismostlyautomaticallycalculatedbyCADmachines.Markerefficiencyabove80%to85%isconsideredgood.

MarkedConsumption:Consumptionofagarmentcalculatedasperthemarkersmadeby

theCADdepartment.Inordertocalculatethismetricthefollowingstepshavetobefollowed:

Makeacutorderplanstatingmarkersandno.ofpliesforeachlay.Makeallthemarkers.Calculatetotallengthoffabricbeingusedonthelays.Dividethisvaluebytotalgarmentstobeproduced.

AchievedConsumption:Thisistheactualconsumptionachievedpergarmentafterthewholeproductionprocessiscompleted.Thisrequiresextensivecalculationbuttheresultgivesarealisticimageoflossofmaterialinthesystem.

Theaboveformulawillshowfinalachievedconsumption.Thelossesonmaterialincurredbythewholefactoryintermsofdeadstock,endbitsandcuttingroomlosses,partchangeandrejectioninsewing,rejectioninfinishingaswellasunshippedgarmentsareincludedinthiscalculation.

Ifuserwantstomeasureonlycuttingroomachievedconsumptionthentheformulashouldbeslightlyaltered.Totalfabricissuedtocuttingdividedbytotalcutgarmentsissuedtosewingdepartmentwillshowtheachievedconsumptionofcuttingroom.

FabricUtilization:Thisistheratiooffabricusedongarmentstofabricavailabletobeused.Thismetrictellsusthefabricutilizationstatusoftheentireorder.Fabricgenerallycosts60%to70%ofthecostofthegarment.Strictcontrolsshouldensurethateveryinchofthefabricisusedproperlyandisaccountedfor.

TotalfabricavailableFabricusedongarment

a.Byweighti.Weighonegarmentofeachsize(garmentshouldbeweighedbeforesewing)ii.Multiplyweightwithnumberofgarmentscutineachsizeiii.DividetotalweightbyGSMandfabricwidthtogettotalmetersusedingarments.

b.ByLengthi.MultiplyMarkerlengthwithitsMarkerefficiencyandnumberofplieslaidinthemarker.ii.Theabovecalculationisdoneforeachmarkerintheorderandthensumofallgivesthetotalmetersusedingarments.Theabovewillgivefabricutilizationfortheorder.Theformulacanbeextendedtocalculateoverallfabricutilizationforthefactoryinamonth.=Fabricallocatedorboughtfortheorder.=thiscanbecalculatedinfollowingways.CutorderPlan

CuttoShipRatio-Thisshowsthepercentageofgarmentsshippedoutoftotalnumberofgarmentscutfortheorder.Itshowsabird’seyeviewoftheentiresystem.Anumbercloseto98%willbeconsideredverywell.Thismeansonly2%ofgarmentsarerejectedorlostinthesystem.

Totalpiecesshipped:Thisshouldbetakenfromfinalpackinglist.Totalpiecescut:Thisshouldbeallthegarmentscutforthisorder.Thisshouldbetakenfromcuttingroomdailyrecords.

Manyfactoriescollectthisinformationasmonthlyaverageaswellasapercentagefor

individualorders.Thisgivesageneralperformancelevelofthecompany.Theremaybevariousreasonsforanambiguousresultandfurtherinvestigationmayberequired.

LabourCostperminute:Thisisaveryimportantmetricwhilecalculatingthepriceofagarment.Ithelpstoquicklycalculatethelabourcostthatwillbeincurredinproductionofthegivengarment.Thiscanbecalculatedoveramonthorayeartogiveanaccuratevaluetocostperminute.Tocalculatelabourcostofaneworder,itsstandardminuteiscalculatedandthenmultipliedtocostperminuteandefficiencytogettheactuallabourcostthatwillbeincurredduringitsproduction.

PlanPerformanceIndex:Thisshowsthepercentageofvariationbetweentheplannedworkandtheactualworkdone.Thishelpsinevaluatinghowefficientisyourfactoryplaninordertomeetyourdeliverydates.Theidealvalueis100%buta97%hitrateshouldbeconsideredgood.

Thisisjustarepresentativefigureandfurtherinvestigationisrequiredtoinvestigatetheresults.Overtime,workoutsourcing,vendordelay,qualitycanaffectthisindexvalueandtheresultmayneedfurtherinvestigation.Forexamplea100%PPImayhavebeenachievedbydoingalotofovertimewhichisnottheexpectedresult.

On-timeDelivery:Thisrepresentsthepercentageofdeliveriesthatafactoryisabletomakeon-timewithoutanydelaysorextensions.

Anon-timedeliverymeansthattheproductsaredeliveredexactlyonthedatetheexporterhaspromisedtothecustomer.Abeforetimedeliveryisequallybadasalatedeliveryasitneedsthebuyertospendonwarehousespaceandmoney.Thissimpleindicatorisaveryimportantfactorinmostbuyers’bookstoevaluatetheirfactoryperformances.CapacityUtilization:Extentorleveltowhichtheproductivecapacityofafactoryisbeingusedingenerationofgoods.Therefore,itreferstotherelationshipbetweenactualoutputthat‘is’producedwiththeinstalledequipmentandmanpower,andthepotentialoutputwhich‘could’beproducedwithit,ifcapacitywasfullyused.

Ifthefactorymakesstandardproduct,capacitycanbeexpressedintermsofnumberofpieces.However,ifthereisahugevariationintheproductsproduced,thentheunitofmeasureshouldideallybenumberofminutesproduced.Thisissummationofeachgarmentproducedmultipliedbyitsstandardminutevalue.Capacityshouldalsobeexpressedinnumberofminutes.

OvertimePercentage:Thepercentageofovertimebeingusedovertotalworkingtime.Asovertimecostsconsiderableamountofmoneytothecompany,atightcontrolshouldbekeptonovertimepercentage.Thiscanbecalculatedoverdays,weeksormonths,representingtheovertimebeingusedinthefactory.Planningdepartmentcanimprovetheirplaninfutureandkeepacheckontheirplanbasedontheseovertimetrends.

OTIF:OTIF(OnTimeinFull),orDIFOT(DeliveredinFullonTime),isoneofthefundamentalmeasurementsforlogisticsperformance.Itmeasures,weathertheSupplyChainwasabletodeliverornot

Theexpectedproduct(referenceandquality)Inthequantityordered(withthetolerancedefinedbythecustomer)Attheplaceagreed

Atthetimeexpectedbythecustomer

ToreachagoodOTIFlevel,allthefunctionsofthesupplychain(amongwhichorderstaking,procurement,suppliers,warehouses,transport…)havetoworkattheirbestlevel.OTIFallowsseeingataglance;howthecompanydeliversitscustomers.

Process,Ranking,Grading,WageStructure,incentiveplans

10JobEvaluation&Compensation

Thereisaconservableuncertaintyamongthetermsjobevaluation,jobanalysis,jobdescriptionandjobspecification.

Jobanalysisorjobevaluationisthecollectionofdataandcriticalevaluationoftheoperations,duties,responsibilitiesandrelationships.Jobdescriptionisthewrittenrecordofduties,responsibilitiesandrequirementsofparticularjob.Jobspecificationiswrittenstatementshowingtheaptitude,qualification,experienceetc.thatwouldbenecessarytoperformaparticularjob.

Therationalebehindthejobevaluationistorewardemployeesfairly,whichhelpstheorganisationtoattractandretainthem.Onthepartofemployeesitprovidesthemthemotivationforthebettermentofperformanceandtheireffectiveness.Equitablecompensationrelatestotheproblemofattractingandretainingemployeeswhichmotivationdirectlyreferstothemonetaryandnomonetaryincentives.

Equityandjusticecoincideaccordingtonaturallaw.Itisclearlyexperiencedthatgreaterfeelingsofequity,themorewillbetheequilibrium.Whenemployeereceivescompensation,hisequityperceptionisaffectedbytwofactors,

1)Effort–outputratio;i.e.whataretheinputsgivenbyemployeeintermsofphysicalandmentaleffort,training,educationandhowheworksandfurnishestaskandhowtheyarerewarded.Thuscompensationtotheworkaccomplishedbyemployeehasgreatimpactinthefutureperformanceanditalsoshowsanimpactonthementaladjustment.Simplyifnumeratorislowanddenominatorishigh,

iftheratioislow,itleadstodissatisfactionwhichresultinlowperformance,lesseffectivenessandlowproductivity.Ontheotherhand,highratiocanalsoleadtooveralldissatisfactionarisingoutofoverpayment.Employeewillfeelguiltyandtrytoworkmoretoshowthatheactuallydeserves,soequityconceptbalancesthesetwoextremesandaccordinglygivesarationalbasistoworkoutthewagesandsalaries.

2)Thecomparisonofaboveratiowithotherperson’sratiowithwhomhehasdirectcontact.HIGHoverrewardedModerateOverrewardedMEDIUMModerateOver

rewardedModerateOverrewarded

LOWModerateUnderrewardedUnderRewardedLOW

Well-designedjobevaluationhelpsbusinessfirminmorethanoneway,

a)Beingasystematicprocess,jobevaluationfixesthewagerateforeachjob.b)Itisconsideredtobesimpleasitiseasilyunderstoodbyall.c)Itestablishestheequitablewagerateforallthejobs,accordingtothejobrequirements.d)Companytrainingprogram,placement,recruitmentselectionandlongrangemanpowerplanning

alwaysfollowjobevaluation.MEDIUMHIGHRELATIVECONTRIBUTION

e)Itenablescompanytogetdataforincorporationinlocalwagesurveystoestablishjobclassification.Allofthesecontributetohealthy,soundandequitablewagestructureinorganisation.Butinpractice,theroleoftradeunionvariesfromoutrightoppositiontocompleteparticipation.Inmanycasesunionsinvolveandprovidefullparticipation.Insuchcases,localunionsselectmemberswhoaretrainedbymanagementandformajointunion-managementcommitteetoworkoutandinstalljobevaluationsystem.

ProcessTheprocessofjobevaluationinvolvesthefollowingsteps:

Gainingacceptance:Beforeundertakingjobevaluation,topmanagementmustexplaintheaimsandusesoftheprogrammetotheemployeesandunions.Toelaboratetheprogramfurther,oralpresentationscouldbemade.Letters,bookletscouldbeusedtoclassifyallrelevantaspectsofthejobevaluationprogramme.Creatingjobevaluationcommittee:Itisnotpossibleforasinglepersontoevaluateallthekeyjobsinanorganization.Usuallyajobevaluationcommitteeconsistingofexperiencedemployees,unionrepresentativesandHRexpertsiscreatedtosettheballrolling.Findingthejobstobeevaluated:Everyjobneednotbeevaluated.Thismaybetootaxingandcostly.Certainkeyjobsineachdepartmentmaybeidentified.Whilepickingupthejobs,caremustbetakentoensurethattheyrepresentthetypeofworkperformedinthatdepartment.Analyzingandpreparingjobdescription:Thisrequiresthepreparationofajobdescriptionandalsoananalysisofjobneedsforsuccessfulperformance.Selectingthemethodofevaluation:Themostimportantmethodofevaluatingthejobsmustbeidentifiednow,keepingthejobfactorsaswellasorganizationaldemandsinmind.Classifyingjobs:Therelativeworthofvariousjobsinanorganisationmaybefoundoutafterarrangingjobsinorderofimportanceusingcriteriasuchasskillrequirements,experienceneeded,underwhichconditionsjobisperformed,typeofresponsibilitiestobeshouldered,degreeofsupervisionneeded,theamountofstresscausedbythejob,etc.Weightscanbeassignedtoeachsuchfactor.Whenwefinallyaddalltheweights,theworthofajobisdetermined.Thepointsmaythenbeconvertedintomonetaryvalues

TechniquesofJobEvaluationAllformsofjobevaluationmethodsaredesignedtoenablemanagementtodeterminehowmuchonejobshouldbepaidascomparedtoothers.Thesystemsareclassifiedundertwocategories.

1)Non–quantitativea.Simplerankingb.grading

2)Quantitativea.Pointsystemb.Factorcomparison

Themostwidelyusedsystemispointsystemandtheleastisrankingsystem.Onecompanycanapplytwomethodsfortwodifferentjobs.

SimpleRanking

Thismethodiswidelyusedinsmallorganisation.Beingaverysimpleandnotexpensivemethod,italsoconsumeslesstimeandpromisesenoughpotential.Beforeactualranking,briefjobdescriptionofallthejobsaretaken.Thenarrangesallthejobsinorderoftheirrelativeworth,withoutanyotherconsideration.Then,thehighestandthelowestjobsaredeterminedwhichserveastherankingreminder.Thesecondmethodisthepairedcomparison,whereeachjobiscomparedwithallotherjobs.Oncethecomparisonisdone,jobsarearrangedaccordingtotheirworth.Themainideaofthistechniqueistorankthejobsinorderoftheirworth.Thesimplicityofthismethodisrathermisleading.Defectsofthesimplerankingmethodare;a)SimplicityisoneofthedisadvantagesasittendstomakeRankJob

measurementsomewhatcrude.1Ab)Measurementofwholejobi.e.allthefactorsaffectingthejobare2Bnotconsidered.3Cc)Absenceofpredeterminedyardsticksleadstopersonalpartiality4D

Theendproductofthismethodisalistofjobsinorderoftheirworth,5E

JobGrading

Inranking,wedon’thavepredecidedscaleofvalue,buthereisoneyardstickconsistingofjobclass.Inthisapproach,jobfactorsapproachisnotconsideredrathertheyaremeasuredasawhole.Accordingtothismethod,apredeterminednumberofjobgroupsorjobclassesareestablishedandjobsareassignedtotheseclassifications.Thismethodplacesgroupsofjobsintojobclassesorjobgrades.Separateclassesmayincludeoffice,clerical,managerial,personnel,etc.Followingisabriefdescriptionofsuchaclassificationinanoffice.

1.ClassI-Executives:FurtherclassificationunderthiscategorymaybeOfficeManager,Deputyofficemanager,Officesuperintendent,Departmentalsupervisor,etc.

2.ClassII-Skilledworkers:UnderthiscategorymaycomethePurchasingassistant,Cashier,Receiptsclerk,etc.3.ClassIII-Semiskilledworkers:UnderthiscategorymaycomeStenotypists,Machine-operators,Switchboardoperatoretc.

4.ClassIV-Unskilledworkers:Thiscategorymaycomprisepeons,messengers,housekeepingstaff,

Daftaris,Fileclerks,Officeboys,etc.Thejobgradingmethodislesssubjectivewhencomparedtotheearlierrankingmethod.Thesystemisveryeasytounderstandandacceptabletoalmostallemployeeswithouthesitation.Onestrongpointinfavorofthemethodisthatittakesintoaccountallthefactorsthatajobcomprises.Thissystemcanbeeffectivelyusedforavarietyofjobs.TheweaknessesoftheGradingmethodare:

Evenwhentherequirementsofdifferentjobsdiffer,theymaybecombinedintoasinglecategory,dependingonthestatusajobcarries.Itisdifficulttowriteall-inclusivedescriptionsofagrade.Themethodoversimplifiessharpdifferencesbetweendifferentjobsanddifferentgrades.Whenindividualjobdescriptionsandgradedescriptionsdonotmatchwell,theevaluators

havethetendencytoclassifythejobusingtheirsubjectivejudgments.

FactorcomparisonmethodorPointmethod

Thismethodiswidelyusedandisconsideredtobeoneofthereliableandsystematicapproachforjobevaluationinmidandlargesizeorganisations.Mostconsultingfirmsadoptthismethod,whichwaspioneeredbyEdwardHayin1943.Here,jobsareexpressedintermsofkeyfactors.Thekeyfactorsare,(i).Efforts,(ii)Responsibility,(iii)Skilland(iv)Workingconditions.Pointsareassignedtoeachfactorafterprioritizingeachfactorinorderofimportance.Thepointsaresummeduptodeterminethewagerateforthejob.Jobswithsimilarpointtotalsareplacedinsimilarpaygrades.Theprocedureinvolvedmaybeexplainedthus:

1.Selectkeyjobs.Identifythefactorscommontoalltheidentifiedjobssuchasskill,effort,responsibility,etc.2.Divideeachmajorfactorintoanumberofsubfactors.Eachsubfactorisdefinedandexpressedclearlyintheorderofimportance,preferablyalongascale.

Themostfrequentfactorsemployedinpointsystemsare(i)Skill(keyfactor);Educationandtrainingrequired,Breadth/depthofexperiencerequired,Socialskillsrequired,Problem-solvingskills,Degreeofdiscretion/useofjudgment,Creativethinking

(ii)Responsibility/Accountability:Breadthofresponsibility,Specializedresponsibility,Complexityofthework,Degreeoffreedomtoact,Numberandnatureofsubordinatestaff,Extentofaccountabilityforequipment/plant,Extentofaccountabilityforproduct/materials;

(iii)Effort:Mentaldemandsofajob,Physicaldemandsofajob,DegreeofpotentialstressTheeducationalrequirements(subfactor)undertheskill(keyfactor)maybeexpressedthusintheorderofimportance.

3.Findthemaximumnumberofpointsassignedtoeachjob(afteraddingupthepointvaluesofallsub-factorsofsuchajob).Thiswouldhelpinfindingtherelativeworthofajob.Forinstance,themaximumpointsassignedtoanofficer’sjobinabankcometo540.Themanager’sjob,afteraddingupkeyfactors+subfactorspoints,maybegettingapointvalueofsay650fromthejobevaluationcommittee.Thisjobisnowpricedatahigherlevel.

4.Oncetheworthofajobintermsoftotalpointsisexpressed,thepointsareconvertedintomoneyvalueskeepinginviewthehourly/dailywagerates.Awagesurveyisusuallyundertakentocollectwageratesofcertainkeyjobsintheorganization.

Marketpricingistheprocessfordeterminingtheexternalvalueofjobs,allowingyoutoestablishwageandsalarystructuresandpayratesthataremarketsensitive.Jobmatchingsessionisconducted.ConstructionofYardsticks.

Itisdonebydecidingthetotalpointsassignedortobeutilizedinasystem.Themost

importantdecisiontobetakeniswhatproportionoftotalpointstobeallocatedtoskill,effort,responsibility,andworkingcondition.Thattosay,adecisionistakenthatifthetotalpointinasystemwouldbe1,000,thenwhatcouldbethepercentagecontributionofeachfactor.Thedeterminationofthiswilldependuponthenatureoftheorganisation.Iftheindustryiswithhighautomationlikeetoneproductionsystemsetc.shouldassignmorepointsforresponsibilitysincethemanualskillistranslatedintomachineskill.Butgenerallyingarmentsskillisgivenmoreimportance.Ifwedecide1,000pointsforthesystemthenitcouldbeasshowninthetable.1Table1FactorNumberofPointsPercentageSkill50050Responsibility20020Effort15015WorkingCondition15015

Total1000100

Skillandresponsibilitywillvarywiththesituation.Assignmentofpointstothevariousfactorsissubjective.Aftertheyardstickisdevelopedthecompositionofpointsanddegreesoftheparticularfactorsareworkedout.Forexample,letusconsiderthatofthetotalvalue140pointsareallocatedtoeducation.Thenasevenpointscalecouldbedevelopedasfollows,Table2EducationPoint1Read,Write,addandsubtract202TwoYearshighschoolorequivalent403FourYearshighschoolor2yearsUniv.orequivalent604FourYearshighschool,plus2-3yeartradetraining805FourYearshighschool,plus4yeartradetraining1006twoorThreeyearcollegeplus4yeartradetraining1207fouryearsdegreeplus4yeartradertaining140

EvaluationofthejobItdemandstheconstructionofreliableyardstickanddetailedjobspecifications,theprocessofevaluationisverysimple.Theprocessconsistofcomparingthejobspecificationsverycarefullyandplacingitaccordingtotheyardsticks.Addingupallthepointswillgivethepointworthofthatjob.Themoredetailthejobspecification,thehighertheaccuracy.

Wagesurvey.Oncethejobshavebeenevaluatedandjobspointshavebeensummedup,thenplacethemaccordingtothetermsofmoney.Thisiswheretheratedjobaretranslatedintomonetaryvalues.Forthewagesurvey,twotypesofsamplesareneeded.First,sampleofkeyjobsandsecond,asampleoffirmsinthelabourmarket.Jobsrequiredifferentpersonnel,intermsofskill,abilityetc.andthusitvariesfromlocaltoregionallevel.Thejobcontentandavailabledataarecarefullyanalyzedandaveragedout,andthiswaythemoneyvaluesofjobsarepreparedandplottedonthechart.

Designingthewagestructure.Similarjobsaregroupedandtreatedasajobclass.Allthejobs,whichcomesunderthatjobclassarepaidthesamewage.Inthepointsystem,suppose,120pointsto150pointsmakeajobclass.Insuchcase,allthejobswhichfetchtotalbetween120and150wouldcarrythesamemonetarycompensation.Thepurposeofgroupingofjobsistofacilitatewageadministration.Factorsaffectingthedesigningofwagestructureare,

a)Labourmarketcondition:ifsupplyoflabourishigherthandemand,thewagewouldbe

relativelylow.b)EconomicConditionofthecountry:thatis,ifstandardoflivingishighitcallsforhigherwage.c)Wagestructureofotherfirmsinthesameindustrydirectlyaffectsthecompany’swagestructure.d)Sometimes,eventhoughthecompetitorspayrelativehigherwage,duetoweakcollectivebargainingpowerofthetradeunion,managementmaysettlewageatarelativelowrate.FactorComparisonSystemThisisanimprovedmethodofrankingsystem.Wherejobfactorsarecomparedratherthanthewholejob.Thestepsare,

a)Selectionofjobcharacteristicsb)Selectionofkeyjobsc)Determinationofcorrectratesofkeyjobsd)Rankingofkeyjobsundereachjobfactore)Allocationofcorrectratetoeachkeyjobf)Evaluationofallotherjobs.g)Designing,adjustingandoperatingthewagestructure.

Thefirstthreestepsarequitesimilartothatofpointsystem.Whilethefourthone,istherankingofallthekeyjobs,toaparticularfactoratatime.Forexample,

SupposeA,B,C,D,andEconsistofkeyjobs.Theyarerankedinsuchawaythatonefactorisconsideredatatime.

SkillResponsibilityeffortWorkingConditionABDDBACECCECDDABEEBA

Afterpreparingthistablethekeyjobsaretoberatedinmoneyworth.HowmuchworthshouldbegiventojobAforsayskillfactorisdeterminedbyevaluationcommittee.

YardstickformonetoryratesCorrectJobRatesSkillresponsibilityEffortsWorkingConditionA20.00A12.00B8.50D2.50D3.00B18.00B7.00A5.50C2.00E2.80C14.00C5.20C4.40E1.80C2.40D10.00D3.20D1.30A1.50B1.50E7.00E1.40E1.00B1.00A1.00

ThenextstepistocompareotherjobsagainstthesefactorsthatisifjobZistobeevaluated,thenhowmuchskillisrequired.IfThen,itsskillequalitysimilartoA,responsibilitysimilartoC,effortssimilartoB,andworkingconditionsimilartoE,thenwhileweconvertstomonetaryterms,

Z=SkillA(12.00)+ResponsibilityC(4.40)+EffortsB(1.00)+WorkingConditionE(2.00)=12+4.40+1.80+2.80=21.00

WageIncentivePlansWageasamonetaryrewardispaidtoanemployeefortheservicebyhim.Oneoftheimportantcomponentsofanywageplanistheincentivehourspaidtotheoperativepersonnel.Thereareagoodnumberofincentiveplansthathavebeendevised.Alltheincentiveplansarebasedonthefundamentalfactorssuchasthestandardtime,time

actuallyworked,timesavedandtheoutputlevelattained.Someofthewageincentiveplansare,

a)Halseypremiumwageplanb)TheRowanplanc)StraightPieceworkpland)TaylorDifferentialpieceworkplane)D’GantIncentiveplanf)EmersonPremiumPlang)100percentTimePremiumPlanh)TheBedauxplanAbbreviationsrRatePerunitTActualTimeWorkedSStandardTimeNTotalNumberofUnitsProducedPPremiumPercentageETotalEmployeeEarnings

HalseyPlan:ittakesintoaccountthetotaltimesavedbytheemployee,whenaccurateperformancestandardshavenotbeenestablished.Thevalueoftimesavedbytheemployeeiscomputedandtheearningsissharedbytheemployeeandtheorganisation.Thetotalearningoftheworkeriscomputedbytheformula

i.e.TotalEmployeeEarning=(RatePerUnitXActualTimeWorked)+PremiumPercentageX(StandardTime–ActualTimeWorked)xRateperunit.Suppose,aworkershouldproduce50unitsin8hoursandheispaidattherateof$3perhour.Ifheproduces100unitsin8Hours,histotalearningsforthedaywouldbe,

E=3x8+0.5(16-8)x3=24+12=$36Where,r=3,T=8Hr.,P=50%,S=(8x100)/50=16hrs.RowanPlan:itwasdevisedinGlasgow,Scotland.Inthisplanthebonusiscalculatedonthebasisofthetimeworked.Thusthepremiumpaidtotheworkerisapercentageofthetimeworked.Ifweconsiderourpreviousexample,thenthetotalearningoftheworkerundertherowanplanshouldbe,

E=3x8+(16-8)/16x3x8=24+8/16x24=24+12=36

Itisworthnotingthat,thisplanisnoteasytounderstandbytheoperativepersonnelanditalsoinvolvesmoreclericalwork.StraightPieceworkPlan:Thisisacommonsystemandiseasytounderstand.Therateperunit,atwhichtheworkershouldbepaidforthenumberofunitsproduced,isdeterminedbypastrecords.Thetotalearningwouldbe,

Fromthepreviousexample,hereristhepiecerateandisequalto48piecesTherefore,

E=rN=0.48x100=$48Taylor’sDifferentialPieceRatePlan:-thiscanbeappliedwhenthejobisclearlydefinedandwhentheconditionsaresuchthatitwouldbepossiblefortheaverageworker

toattaintheperformancetarget.TheimportantfeaturesofTylor’sPlanare,

a)Itdoesnotguaranteeadayrate.b)Itcallsfortwopiecerates.Ahighonewhentheworkerattainorexceedsthestandardandalowonewhenhefailstoattainthestandard.Itmeansworkerwouldbepaidhighforachievingthestandardandwouldreceivealowpayincasehefailstoachievethestandard.Theoneaverageofthisplanisthat,itmotivatestheworkertoexceedoratleastmaintainthestandard.Atthesameitalsoplacesaheavyresponsibilityonmanagementtoestablishtheworkstandard.Carefullysothattheworkerwouldnotfeelthatheisunjustlypenalized.Theformulaforcomputinghisearningsunderthissystemissameasthestraightpieceratesystem,theonlydifferenceisthatitprovidesfortworates,E=rN-whenworkerfailstoattainstandardE=r1N-Whentheworkerexceedsorattainstheworkstandard.

CalculatetheearningsofworkersAandBunderStraightPiece-rateSystemandTaylor’sDifferentialPiece-rateSystemfromthefollowingparticulars:Normalrateperhour=1.80Standardtimeperunit=20seconds

Differentialstobeapplied:80%ofpieceratebelowstandard120%ofpiecerateatorabovestandard.WorkerAproduces1,300unitsperdayandworkerBproduces1,500unitsperday.StandardProductionper20sec=1unitStandardProductionperMinute=60/20=3StandardproductionPerhour=3x60=180piecesStandardProductionperdayof8hr=180x8=1440NormalratePerProduction=1.80NormalPiecerate=1.80/180=0.01LowPieceratebelowstdproduction=0.01x80/100=0.008HighPiecerateatoroverstd=0.01x120/100=0.012=WorkerA=13001300unitsproduction=1300x0.008=10.40if@nstraightpiecesytem=1300x0.01=13.00=WorkerB=15001500unitsproduction=1500x0.012=18.00if@nstraightpiecesystem=1500x0.01=15.00

D’GrandIncentiveplan:-thisistheonlyplanthatpaysanincentivepercentagemultipliedbythevalueofstandardplan.Thisalsoprovidestwodifferentrateplansforstandardandsubstandardwork.Howeveritdoesguaranteeadayratetotheworker.TheGant’ssystemallowsvariouspremiumpercentageforbonuspayments,itallowworkertodrawmorethanwhathewouldreceiveunderstraightsystemor100percentagepremium

plan.Theformulausedis,

Usingthefirstproblemthetotalearningsoftheworkerinthiscausewouldbeequalto,E=3x16+1/3x3x16=48+16=$64

EmersonPremiumplan:-Underthe100%timepremiumplantheworkerispaidthefullvalueofthetimesaved.Thisplancallsforthedeterminationofaccuratetimestandardsthroughtimeandmotionstudy.Thisplanalsoguaranteedayratetotheworker.

AndwhentheworkerfailstoattainthestandardE=rSwillbeused.Takingtheoriginalexample,E=3x8=24atorbelowstandardE=3x16=48abovestandard.

BedauxPlan:-thisisalsotimesavingbonusplan,underthisplanthebasicunitoftimeistheunit.Eachjobisratedonthebasisofstandardworkunitallowedforitsperformance.Thebaserateforeachjobisguaranteedandincentiveispaidforperformanceabovestandard.Whentheworkerispaidforthefullallowedtime,thecomputationofearningswouldbe,

Nooneincentivesystemofitselfisthesafeinstrumentforincreasingefficiency.Someconditionswhichmustprevailbeforeinstallingabonussystem.

1.IfindividualschemesaretobeuseditisimportantthattheStandardTimesareaccurateandconsistent2.TheremustbesufficientWIPtoallowtheworkerstoworkattheirownspeedandnotbedependentonotherssupplyingthem.3.Groupschemesdonothavethesame“incentivePull”asanindividualscheme.

4.Anincentiveschemewillnotsolveproductionproblems.Ifproductionisnotrunningsmoothlydonotattempttointroduceanincentivescheme.5.Operator’sperformancerecords,sectionreportsandlosttimereports,shouldallberunningsatisfactorilyandhavebeenrunningforareasonableperiodoftimebeforeinstallingincentives.6.Bonuspaymentsshouldbemadeoverasshortaperiodaspossible.Ifpractical,operatorsshouldbeinformedoftheirearningsondailybasis.7.Bonuspaymentsshouldbepaiddailywhenachievementisoverthestartinglevel.Bonusearningsshouldnotbereducediftheoperatorfallsbelowthestartingrateonsomedays,however,itisimportanttomonitoroperatorsperformancecarefullytoensurethattheyarenot“keepingbacktickets”onthepoordays,andreleasingthemongooddays,therebyartificiallyinflatingtheirbonuspayments.

8.Bonusshouldnotbepaidunlessitisearned.Whereverpossible,averagebonusratesshouldnotbepaidfor“offstandardtime”,otherwisetheoperatorisencouragedtoremain“offstandard”foraslongasispossible.

9.Ifthelevelofbasicwageincreases,itisnecessarytopushupthelevelsofbonusearnings,sothatthepercentageofbonusearnedwillremainthesame,otherwisethemotivatingfactorsofabonusschemewillbereduced.

10.Ifanattendancebonusisinoperation,itmakessensethatthelastdayofthetime

periodshouldcomeinsidewiththetraditionallyworstdayofabsenteeismnormallythisaMonday.Letusdo,

1.Christinehasanattendedtimeof525minutes,losttimeof37minutesandproduced300mins.Whatisherefficiency?2.Janethasattendedtimeof525mins,losttimeof27minsformachinetrouble,and62minsonsamples.Theminutesonherticketforthedayamountedto400.Thebonusschemeinthisfactorypays0.018centsperminuteonstandardforeverypercentageincreaseabove70%.WhatisJanet’sbonus?3.Thenormaldayhasatotalattendedtimeof525minutes,operator163left45minutesearlytogotothedoctor.Beforesheleftshedid:25bundlesofjoinshoulders

16bundlesofsetsleeves3bundlesofsideseams8minsperbundle10minsperbundle15minsperbundle

Hermachinewasbrokenfrom08:30until08:45andsheworkedonsamplesfrom12:00until12:30.Whatisherefficiency?4.CompanyBwishestostartabonusschemeat70%andpayR15.30for100%.Whatisthebonusrate?(Workingweekis42,5hours).Answer,1)Efficiency=300/(525-37)=61.4%

2)525–89=436Minsproduced=400Efficiency=91.7%

3)Attendedtime=525–45=480Losttime:

MT=15Samples=30Total=45

Timeonstandard=435

Minutesproduced:25x8=20016x10=1603x15=45Total=405

Efficiency=405/435x100=93%4)BonusRate=1530x1255030=0.02cents