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Operations Operations ManagementManagementChapter 5 –Chapter 5 –Short-Term SchedulingShort-Term Scheduling

PowerPoint presentation to accompanyPowerPoint presentation to accompanyPowerPoint presentation to accompanyPowerPoint presentation to accompanyHeizer/Render Heizer/Render Principles of Operations Management, Principles of Operations Management, 66eeOperations Management,Operations Management, 88ee

© 2006 Prentice Hall, Inc. 15 – 1© 2006 Prentice Hall, Inc.

Operations Management, Operations Management, 88e e

O tlineO tlineOutlineOutline The Strategic Importance Of ShortThe Strategic Importance Of Short--

Term SchedulingTerm Schedulinggg Scheduling IssuesScheduling Issues

Forward and Backward SchedulingForward and Backward SchedulingScheduling CriteriaScheduling Criteriagg

© 2006 Prentice Hall, Inc. 15 – 2

O tlineO tline Contin edContin edOutline Outline –– ContinuedContinued

Scheduling ProcessScheduling Process--Focused Focused FacilitiesFacilitiesFacilitiesFacilities

Loading JobsLoading JobsGantt ChartsGantt Charts

A i t M th dA i t M th dAssignment MethodAssignment Method


O tlineO tline Contin edContin edOutline Outline –– ContinuedContinued Sequencing JobsSequencing Jobs

Priority Rules for Dispatching JobsPriority Rules for Dispatching JobsPriority Rules for Dispatching JobsPriority Rules for Dispatching JobsSequencing N Jobs on Two Sequencing N Jobs on Two

Machines: Johnson’s RuleMachines: Johnson’s RuleMachines: Johnson s RuleMachines: Johnson s RuleLimitations Of RuleLimitations Of Rule--Based Based

Dispatching SystemsDispatching Systems


Strategic Importance ofStrategic Importance ofStrategic Importance of Strategic Importance of ShortShort--Term SchedulingTerm Scheduling

Effective and efficient scheduling Effective and efficient scheduling b titi d tb titi d tcan be a competitive advantagecan be a competitive advantage

Faster movement of goods through a Faster movement of goods through a g gg gfacility means better use of assets facility means better use of assets and lower costsand lower costs

Additional capacity resulting from Additional capacity resulting from faster throughput improves customer faster throughput improves customer g p pg p pservice through faster deliveryservice through faster delivery

Good schedules result in moreGood schedules result in more


Good schedules result in more Good schedules result in more reliable deliveriesreliable deliveries

S h d li IS h d li IScheduling IssuesScheduling Issues

Scheduling deals with the timing of Scheduling deals with the timing of operationsoperationsoperationsoperations

The task is the allocation and The task is the allocation and i iti ti f d di iti ti f d dprioritization of demandprioritization of demand

Significant issues areSignificant issues are Significant issues areSignificant issues areThe type of scheduling, forward or The type of scheduling, forward or

backwardbackwardbackwardbackwardThe criteria for prioritiesThe criteria for priorities


Scheduling Scheduling ggIssuesIssues


Figure 15.1Figure 15.1

Scheduling DecisionsScheduling DecisionsScheduling DecisionsScheduling DecisionsOrganizationOrganization Managers Must Schedule the FollowingManagers Must Schedule the FollowingOrganizationOrganization Managers Must Schedule the FollowingManagers Must Schedule the Following

Arnold Palmer Arnold Palmer HospitalHospital

Operating room useOperating room usePatient admissionsPatient admissionsNursing, security, maintenance staffsNursing, security, maintenance staffsNursing, security, maintenance staffsNursing, security, maintenance staffsOutpatient treatmentsOutpatient treatments

University of University of MissouriMissouri

Classrooms and audiovisual equipmentClassrooms and audiovisual equipmentStudent and instructor schedulesStudent and instructor schedulesGraduate and undergraduate coursesGraduate and undergraduate courses

LockheedLockheed--Martin Martin factoryfactory

Production of goodsProduction of goodsPurchases of materialsPurchases of materialsyyWorkersWorkers

Hard Rock CafeHard Rock Cafe Chef, waiters, bartendersChef, waiters, bartendersDelivery of fresh foodsDelivery of fresh foodsEntertainersEntertainersOpening of dining areasOpening of dining areas

Delta AirlinesDelta Airlines Maintenance of aircraftMaintenance of aircraftD i blD i bl


Departure timetablesDeparture timetablesFlight crews, catering, gate, ticketing personnelFlight crews, catering, gate, ticketing personnelTable 15.1Table 15.1

Forward and BackwardForward and BackwardForward and Backward Forward and Backward SchedulingSchedulinggg

Forward scheduling starts as soon Forward scheduling starts as soon ggas the requirements are knownas the requirements are known

Produces a feasible scheduleProduces a feasible schedule Produces a feasible schedule Produces a feasible schedule though it may not meet due datesthough it may not meet due dates

Frequently results in Frequently results in excessive workexcessive work--inin--e cess e oe cess e oprocess inventoryprocess inventory

DD


Due Due DateDateNowNow

Forward and BackwardForward and BackwardForward and Backward Forward and Backward SchedulingSchedulinggg

Backward scheduling begins with Backward scheduling begins with g gg gthe due date and schedules the final the due date and schedules the final operation firstoperation firstoperation firstoperation first

Schedule is produced by working Schedule is produced by working b k d th h thb k d th h thbackwards though the processesbackwards though the processes

Resources may not Resources may not esou ces ay otesou ces ay otbe available to be available to accomplish theaccomplish the DD


accomplish the accomplish the scheduleschedule

Due Due DateDateNowNow

S h d li C it iS h d li C it iScheduling CriteriaScheduling Criteria

1.1. Minimize completion timeMinimize completion time2.2. Maximize utilization of facilitiesMaximize utilization of facilities33 Minimize workMinimize work inin process (WIP)process (WIP)3.3. Minimize workMinimize work--inin--process (WIP) process (WIP)

inventoryinventory4.4. Minimize customer waiting timeMinimize customer waiting time

Optimize the use of resources so Optimize the use of resources so that production objectives are metthat production objectives are met


that production objectives are metthat production objectives are met

Scheduling ProcessScheduling Process--Scheduling ProcessScheduling Process--Focused FacilitiesFocused Facilities

1.1. Schedule incoming orders without Schedule incoming orders without violating capacity constraintsviolating capacity constraintsviolating capacity constraintsviolating capacity constraints

2.2. Check availability of tools and materials Check availability of tools and materials before releasing an orderbefore releasing an orderbefore releasing an orderbefore releasing an order

3.3. Establish due dates for each job and Establish due dates for each job and check progresscheck progresscheck progresscheck progress

4.4. Check work in progressCheck work in progress5.5. Provide feedbackProvide feedback6.6. Provide work efficiency statistics and Provide work efficiency statistics and


yymonitor timesmonitor times

Loading JobsLoading JobsLoading JobsLoading Jobs

Assign jobs so that costs, idle Assign jobs so that costs, idle time or completion time aretime or completion time aretime, or completion time are time, or completion time are minimizedminimized

Two forms of loadingTwo forms of loadingCapacity orientedCapacity orientedCapacity orientedCapacity orientedAssigning specific jobs to work Assigning specific jobs to work

centerscenterscenterscenters


Gantt ChartsGantt ChartsGantt ChartsGantt Charts Load chart shows the loading and Load chart shows the loading and

idle times of departments, machines, idle times of departments, machines, p , ,p , ,or facilitiesor facilities

Displays relative workloads overDisplays relative workloads over Displays relative workloads over Displays relative workloads over timetime

Schedule chart monitors jobs in Schedule chart monitors jobs in processprocesspp

All Gantt charts need to be updated All Gantt charts need to be updated frequentlyfrequently


frequentlyfrequently

G tt L d Ch t E lG tt L d Ch t E lGantt Load Chart ExampleGantt Load Chart Example

Day Monday Tuesday Wednesday Thursday FridayWork Center

Metalworks

Mechanical

Job 349

Job 408

Job 350

Job 349Mechanical

Electronics Job 349Job 408

Job 408Job 349

Painting Job 349Job 408Job 295

ProcessingProcessing UnscheduledUnscheduled Center not availableCenter not available


Figure Figure 1515..33

Gantt Schedule ChartGantt Schedule ChartGantt Schedule Chart Gantt Schedule Chart ExampleExample

Job Day 1

Day 2

Day 3

Day 4

Day 5

Day 6

Day 7

Day 8

Start of an Start of an activityactivity

1 2 3 4 5 6 7 8

A

End of an End of an activityactivity

Scheduled Scheduled

BMaintenance

activity time activity time allowedallowed

Actual work Actual work B progressprogress

Nonproduction Nonproduction timetime

Ct et e

Point in time Point in time when chart is when chart is reviewedreviewed


Figure Figure 1515..44 NowNow

Assignment MethodAssignment MethodAssignment MethodAssignment Method

A special class of linear A special class of linear programming models that assignprogramming models that assignprogramming models that assign programming models that assign tasks or jobs to resourcestasks or jobs to resources

Objective is to minimize cost or Objective is to minimize cost or timetime

Only one job (or worker) is Only one job (or worker) is assigned to one machine (orassigned to one machine (orassigned to one machine (or assigned to one machine (or project)project)



Build a table of costs or time Build a table of costs or time associated with particularassociated with particularassociated with particular associated with particular assignmentsassignments

TypesetterTypesetterJobJob AA BB CCRR--3434 $$1111 $$1414 $ $ 66SS--6666 $ $ 88 $$1010 $$1111TT--5050 $ $ 99 $$1212 $ $ 77



1.1. Create zero opportunity costs by Create zero opportunity costs by repeatedly subtracting the lowest costsrepeatedly subtracting the lowest costsrepeatedly subtracting the lowest costs repeatedly subtracting the lowest costs from each row and columnfrom each row and column

22 Draw the minimum number of verticalDraw the minimum number of vertical2.2. Draw the minimum number of vertical Draw the minimum number of vertical and horizontal lines necessary to cover and horizontal lines necessary to cover all the zeros in the table. If the numberall the zeros in the table. If the numberall the zeros in the table. If the number all the zeros in the table. If the number of lines equals either the number of of lines equals either the number of rows or the number of columns, rows or the number of columns, proceed to step proceed to step 44. Otherwise proceed to . Otherwise proceed to step step 33..



3.3. Subtract the smallest number not Subtract the smallest number not covered by a line from all other covered by a line from all other yyuncovered numbers. Add the same uncovered numbers. Add the same number to any number at the number to any number at the intersection of two lines. Return to intersection of two lines. Return to step step 22..

4.4. Optimal assignments are at zero Optimal assignments are at zero locations in the table. Select one, draw locations in the table. Select one, draw li h h h d lli h h h d llines through the row and column lines through the row and column involved, and continue to the next involved, and continue to the next assignmentassignment


assignment.assignment.

Assignment ExampleAssignment ExampleAssignment ExampleAssignment ExampleT ttT tt

AA BB CCJobJobRR 3434 $$1111 $$1414 $$ 66

TypesetterTypesetter

RR--3434 $$1111 $$1414 $ $ 66SS--6666 $ $ 88 $$1010 $$1111TT--5050 $$ 99 $$1212 $$ 77TT 5050 $ $ 99 $$1212 $ $ 77

Step Step 11a a -- RowsRows Step Step 11b b -- ColumnsColumns

AA BB CCJobJob

TypesetterTypesetterAA BB CC

JobJob


RR--3434 $ $ 55 $ $ 88 $ $ 00SS--6666 $ $ 00 $ $ 22 $ $ 33TT 5050 $$ 22 $$ 55 $$ 00

RR--3434 $ $ 55 $ $ 66 $ $ 00SS--6666 $ $ 00 $ $ 00 $ $ 33TT 5050 $$ 22 $$ 33 $$ 00


TT--5050 $ $ 22 $ $ 55 $ $ 00 TT--5050 $ $ 22 $ $ 33 $ $ 00

Assignment ExampleAssignment ExampleAssignment ExampleAssignment ExampleTh ll t dTh ll t dStep Step 2 2 -- LinesLines


The smallest uncovered The smallest uncovered number is number is 2 2 so this is so this is subtracted from all other subtracted from all other

AA BB CCJobJobRR--3434 $ $ 55 $ $ 66 $ $ 00

uncovered numbers and uncovered numbers and added to numbers at the added to numbers at the intersection of linesintersection of lines$$ $$ $$

SS--6666 $ $ 00 $ $ 00 $ $ 33TT--5050 $ $ 22 $ $ 33 $ $ 00 Step Step 3 3 -- SubtractionSubtraction

intersection of linesintersection of lines

Because only two lines Because only two lines are needed to cover allare needed to cover all

AA BB CCJobJob


are needed to cover all are needed to cover all the zeros, the solution the zeros, the solution is not optimalis not optimal

RR--3434 $ $ 33 $ $ 44 $ $ 00SS--6666 $ $ 00 $ $ 00 $ $ 55TT 5050 $$ 00 $$ 11 $$ 00


TT--5050 $ $ 00 $ $ 11 $ $ 00

Assignment ExampleAssignment ExampleAssignment ExampleAssignment ExampleStart by assigning RStart by assigning R 3434 totoStep Step 2 2 -- LinesLines

AA BB CCTypesetterTypesetter

Start by assigning RStart by assigning R--34 34 to to worker C as this is the only worker C as this is the only possible assignment for possible assignment for

k Ck C J b TJ b T 5050 ttAA BB CCJobJobRR--3434 $ $ 33 $ $ 44 $ $ 00

worker C.worker C. Job TJob T--50 50 must must go to worker A as worker C go to worker A as worker C is already assigned. This is already assigned. This

SS--6666 $ $ 00 $ $ 00 $ $ 55TT--5050 $ $ 00 $ $ 11 $ $ 00 Step Step 4 4 -- AssignmentsAssignments

y gy gleaves Sleaves S--66 66 for worker B.for worker B.

Because three lines are Because three lines are needed, the solution isneeded, the solution is

AA BB CCJobJob


needed, the solution is needed, the solution is optimal and optimal and assignments can be assignments can be mademade

JobJobR-34 $ $ 33 $ $ 44 $ 0S-66 $ $ 00 $ 0 $ $ 55


mademadeT-50 $ 0 $ $ 11 $ $ 00

Assignment ExampleAssignment ExampleAssignment ExampleAssignment Example

From the original cost table

Minimum cost = $6 + $10 + $9 = $25

Step Step 4 4 -- AssignmentsAssignments

AA BB CCJobJob

TypesetterTypesetterAA BB CC

J bJ b


JobJobR-34 $ $ 33 $ $ 44 $ 0S-66 $ $ 00 $ 0 $ $ 55

JobJobRR--3434 $$1111 $$1414 $ $ 66SS--6666 $ $ 88 $$1010 $$1111


T-50 $ 0 $ $ 11 $ $ 00TT--5050 $ $ 99 $$1212 $ $ 77

Sequencing JobsSequencing JobsSequencing JobsSequencing Jobs

Specifies the order in which jobs Specifies the order in which jobs should be performed at work centersshould be performed at work centersshould be performed at work centersshould be performed at work centers

Priority rules are used to dispatch or Priority rules are used to dispatch or j bj bsequence jobssequence jobs

FCFS: First come, first servedFCFS: First come, first served,,SPT: Shortest processing timeSPT: Shortest processing timeEDD E li t d d tEDD E li t d d tEDD: Earliest due dateEDD: Earliest due dateLPT: Longest processing timeLPT: Longest processing time


g p gg p g

Sequencing ExampleSequencing ExampleSequencing ExampleSequencing ExampleApply the four popular sequencing rules Apply the four popular sequencing rules to these five jobsto these five jobs

Job Work Job Work (Processing) Time(Processing) Time

Job Due Job Due DateDate

JobJob(Processing) Time(Processing) Time

(Days)(Days)DateDate

(Days)(Days)AA 66 88BB 22 66CC 88 1818DD 33 1515EE 99 2323


Sequencing ExampleSequencing ExampleSequencing ExampleSequencing Example

Job WorkJob Work

FCFS: Sequence AFCFS: Sequence A--BB--CC--DD--EE

Job Job SequenceSequence

Job Work Job Work (Processing) (Processing)

TimeTimeFlow Flow TimeTime


Job Job LatenessLateness

AA 66 66 88 00

BB 22 88 66 22

CC 88 1616 1818 00DD 33 1919 1515 44EE 99 2828 2323 55

2828 7777 1111



Job WorkJob Work

FCFS: Sequence AFCFS: Sequence A--BB--CC--DD--EETotal flow time






Average completion time = = 77/5 = 15.4 daysTotal flow timeNumber of jobs

U ili i 28/ 36 4%Total job work time

AA 66 66 88 00

BB 22 88 66 22

Utilization = = 28/77 = 36.4%j

Total flow time

Average number of = = 77/28 = 2 75 jobsTotal flow time

CC 88 1616 1818 00DD 33 1919 1515 44

jobs in the system = = 77/28 = 2.75 jobsTotal job work time

Average job lateness = = 11/5 = 2 2 daysTotal late days

EE 99 2828 2323 55

2828 7777 1111

Average job lateness = = 11/5 = 2.2 daysNumber of jobs



Job WorkJob Work

SPT: Sequence BSPT: Sequence B--DD--AA--CC--EE






BB 22 22 66 00

DD 33 55 1515 00

AA 66 1111 88 33CC 88 1919 1818 11EE 99 2828 2323 55

2828 6565 99



Job WorkJob Work

SPT: Sequence BSPT: Sequence B--DD--AA--CC--EETotal flow time






Average completion time = = 65/5 = 13 daysTotal flow timeNumber of jobs

U ili i 28/6 43 1%Total job work time

BB 22 22 66 00

DD 33 55 1515 00


Total flow time


AA 66 1111 88 33CC 88 1919 1818 11



EE 99 2828 2323 55

2828 6565 99




Job WorkJob Work

EDD: Sequence BEDD: Sequence B--AA--DD--CC--EE






BB 22 22 66 00

AA 66 88 88 00

DD 33 1111 1515 00CC 88 1919 1818 11EE 99 2828 2323 55

2828 6868 66



Job WorkJob Work

EDD: Sequence BEDD: Sequence B--AA--DD--CC--EETotal flow time








BB 22 22 66 00

AA 66 88 88 00


Total flow time


DD 33 1111 1515 00CC 88 1919 1818 11



EE 99 2828 2323 55

2828 6868 66




Job WorkJob Work

LPT: Sequence ELPT: Sequence E--CC--AA--DD--BB






EE 99 99 2323 00

CC 88 1717 1818 00

AA 66 2323 88 1515DD 33 2626 1515 1111BB 22 2828 66 2222

2828 103103 4848



Job WorkJob Work

LPT: Sequence ELPT: Sequence E--CC--AA--DD--BBTotal flow time








EE 99 99 2323 00

CC 88 1717 1818 00

Utilization = = 28/103 = 27.2%j

Total flow time


AA 66 2323 88 1515DD 33 2626 1515 1111



BB 22 2828 66 2222

2828 103103 4848




Summary of RulesSummary of Rules

RuleRule

Average Average Completion Completion Time (Days)Time (Days)

Utilization Utilization (%)(%)

Average Number Average Number of Jobs in of Jobs in

SystemSystem

Average Average Lateness Lateness

(Days)(Days)( y )( y ) ( )( ) yy ( y )( y )

FCFSFCFS 15.415.4 36.436.4 2.752.75 2.22.2

SPTSPT 13 013 0 43 143 1 2 322 32 1 81 8SPTSPT 13.013.0 43.143.1 2.322.32 1.81.8

EDDEDD 13.613.6 41.241.2 2.432.43 1.21.2

LPTLPT 20.620.6 27.227.2 3.683.68 9.69.6


Comparison ofComparison ofComparison of Comparison of Sequencing RulesSequencing Rules

No one sequencing rule excels on all No one sequencing rule excels on all criteriacriteriacriteriacriteria

SPT does well on minimizing flow time and SPT does well on minimizing flow time and number of jobs in the systemnumber of jobs in the systemnumber of jobs in the systemnumber of jobs in the system

But SPT moves long jobs to the end which But SPT moves long jobs to the end which lt i di ti fi d tlt i di ti fi d tmay result in dissatisfied customersmay result in dissatisfied customers

FCFS does not do especially well (or FCFS does not do especially well (or poorly) on any criteria but is perceived as poorly) on any criteria but is perceived as fair by customersfair by customers


EDD minimizes latenessEDD minimizes lateness

Sequencing N Jobs on TwoSequencing N Jobs on TwoSequencing N Jobs on Two Sequencing N Jobs on Two Machines: Johnson’s RuleMachines: Johnson’s Ruleac es Jo so s u eac es Jo so s u e

Works with two or more jobs that Works with two or more jobs that pass through the same two pass through the same two machines or work centersmachines or work centers

Minimizes total production time andMinimizes total production time and Minimizes total production time and Minimizes total production time and idle timeidle time


J h ’ R lJ h ’ R lJohnson’s RuleJohnson’s Rule1.1. List all jobs and times for each work List all jobs and times for each work

centercenter2.2. Choose the job with the shortest activity Choose the job with the shortest activity

time. If that time is in the first work center,time. If that time is in the first work center,time. If that time is in the first work center, time. If that time is in the first work center, schedule the job first. If it is in the second schedule the job first. If it is in the second work center, schedule the job last.work center, schedule the job last.jj

3.3. Once a job is scheduled, it is eliminated Once a job is scheduled, it is eliminated from the listfrom the listfrom the list from the list

4.4. Repeat steps 2 and 3 working toward the Repeat steps 2 and 3 working toward the center of the sequencecenter of the sequence


center of the sequencecenter of the sequence

Johnson’s Rule ExampleJohnson’s Rule ExampleJohnson s Rule ExampleJohnson s Rule ExampleWork Center 1 Work Center 1 Work Center 2 Work Center 2

JobJob (Drill Press)(Drill Press) (Lathe)(Lathe)AA 55 22BB 33 66BB 33 66CC 88 44DD 1010 77DD 1010 77EE 77 1212



JobJob (Drill Press)(Drill Press) (Lathe)(Lathe)AA 55 22BB 33 66BB 33 66CC 88 44DD 1010 77

DD AABB CCEEDD 1010 77EE 77 1212




BB AACCDDEEDD 1010 77EE 77 1212

TiTi 00 33 1010 2020 2828 3333TimeTime 00 33 1010 2020 2828 3333

B ACDEWC 1

WC 2




BB AACCDDEEDD 1010 77EE 77 1212

TiTi 00 33 1010 2020 2828 3333TimeTime 00 33 1010 2020 2828 3333

B ACDEWC 1

TimeTime 00 11 33 55 77 99 1010 1111 1212 1313 1717 1919 21 22 2321 22 23 2525 2727 2929 3131 3333 3535

B ACDEWC 2


TimeTime 00 11 33 55 77 99 1010 1111 1212 1313 1717 1919 21 22 2321 22 23 2525 2727 2929 3131 3333 3535

BB EE DD CC AA

Limitations of RuleLimitations of Rule BasedBasedLimitations of RuleLimitations of Rule--Based Based Dispatching SystemsDispatching Systems

11 Scheduling is dynamic and rulesScheduling is dynamic and rules1.1. Scheduling is dynamic and rules Scheduling is dynamic and rules need to be revised to adjust to need to be revised to adjust to changeschangeschangeschanges

2.2. Rules do not look upstream or Rules do not look upstream or downstreamdownstream

33 Rules do not look beyond dueRules do not look beyond due3.3. Rules do not look beyond due Rules do not look beyond due datesdates


Fi it C it S h d liFi it C it S h d liFinite Capacity SchedulingFinite Capacity Scheduling

Overcomes disadvantages of ruleOvercomes disadvantages of rule--based based systems by providing an interactive, systems by providing an interactive, y y p g ,y y p g ,computercomputer--based graphical systembased graphical system

May include rules and expert systems orMay include rules and expert systems or May include rules and expert systems or May include rules and expert systems or simulation to allow realsimulation to allow real--time response to time response to system changessystem changesy gy g

Initial data often from an MRP systemInitial data often from an MRP system FCS ll th b l i f d liFCS ll th b l i f d li FCS allows the balancing of delivery FCS allows the balancing of delivery

needs and efficiencyneeds and efficiency


Fi it C it S h d liFi it C it S h d liFinite Capacity SchedulingFinite Capacity Scheduling

MRP Data• Master

schedule

• Routing files• Work center

information

Interactive Finite Capacity SchedulingInteractive Finite Capacity Scheduling

• BOM• Inventory

information

ToolingPriority rules

Tooling and other resources

• Expert systems

• Simulation Setups and

run timemodels


Figure Figure 1515..55

Finite Capacity SchedulingFinite Capacity Schedulingp y gp y g


Scheduling ServicesScheduling ServicesScheduling ServicesScheduling ServicesService systems differ from manufacturingService systems differ from manufacturingService systems differ from manufacturingService systems differ from manufacturing

ManufacturingManufacturing ServicesServicesggSchedules machines Schedules machines and materialsand materials

Schedule staffSchedule staff

Inventories used to Inventories used to smooth demandsmooth demand

Seldom maintain Seldom maintain inventoriesinventories

M hiM hi i t i di t i d L bL b i t i di t i dMachineMachine--intensive and intensive and demand may be smoothdemand may be smooth

LaborLabor--intensive and intensive and demand may be variabledemand may be variable

Scheduling may be boundScheduling may be bound Legal issues may constrainLegal issues may constrainScheduling may be bound Scheduling may be bound by union contractsby union contracts

Legal issues may constrain Legal issues may constrain flexible schedulingflexible scheduling

Few social or behavioral Few social or behavioral Social and behavioral Social and behavioral


issuesissues issues may be quite issues may be quite importantimportant

Scheduling ServicesScheduling ServicesScheduling ServicesScheduling Services

Hospitals have complex scheduling Hospitals have complex scheduling system to handle complex processes system to handle complex processes and material req irementsand material req irementsand material requirementsand material requirements

Banks use a crossBanks use a cross--trained and flexible trained and flexible workforce and partworkforce and part--time workerstime workers

Airlines must meet complex FAA and Airlines must meet complex FAA and ppunion regulations and often use linear union regulations and often use linear programming to develop optimal programming to develop optimal schedulesschedules

2424//7 7 Operations use flexible workers and Operations use flexible workers and


ppvariable schedulesvariable schedules

D d M tD d M tDemand ManagementDemand Management

Appointment or reservation Appointment or reservation systemssystemssystemssystems

FCFS sequencing rulesFCFS sequencing rules Discounts or other promotional Discounts or other promotional

schemesschemesschemesschemes When demand management is not When demand management is not

f ibl i itf ibl i itfeasible, managing capacity feasible, managing capacity through staffing flexibility may be through staffing flexibility may be

dd© 2006 Prentice Hall, Inc. 15 – 49

usedused

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