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Review of Cellular Review of Cellular ManufacturingManufacturing

Strategies and Concepts Strategies and Concepts

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STRATEGIC OBJECTIVES FORSTRATEGIC OBJECTIVES FOR MANUFACTURINGMANUFACTURING

REDUCE Manufacturing CostREDUCE Manufacturing CostREDUCE Manufacturing Lead TimeREDUCE Manufacturing Lead Time

Improve QUALITYImprove QUALITYImprove SERVICEImprove SERVICE

Lower PRICELower PRICE

Increase Market Share ($)Increase Market Share ($)

Increased PROFITSIncreased PROFITSIncreased WAGESIncreased WAGES

Increased JOB SECURITYIncreased JOB SECURITY

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Flow Configurations for Flow Configurations for Machine LayoutMachine Layout

Process of Department LayoutProcess of Department Layout Product LayoutProduct Layout Fixed Position LayoutFixed Position Layout Hybrid LayoutHybrid Layout Manufacturing Work cellManufacturing Work cell GT Flow line Work cellGT Flow line Work cell

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Transfer Transfer LineLine

GT Flow Line CellsGT Flow Line Cells

GT CellsGT Cells

Job ShopJob Shop

Low Product Variety HighLow Product Variety High

Low

Pro

duct

Qua

ntity

Hig

hLo

w

P

rodu

ct Q

uant

ity

H

igh

Departmental Layout: MfgDepartmental Layout: Mfg

S S S

S S S

T T T

T T T

T T T

G G G

G G G

M

M

M

B B

B B

GC GC

GC GC

HT

HTHT

Sawing Turning

Heat Treating

Grinding

Milling

BoringGear Cut

“Shaft”

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CharacteristicsCharacteristicsof Department Layoutsof Department Layouts

Low Volume, High Variety Production with Random Low Volume, High Variety Production with Random Routing (Spaghetti-Like Flow)Routing (Spaghetti-Like Flow)

General Purpose Machines--General Purpose Machines-- Machine setups are frequent and longMachine setups are frequent and long Work-In-Process -- HighWork-In-Process -- High Throughput Rates tend to be LowThroughput Rates tend to be Low Material Handling -- HighMaterial Handling -- High Operator Utilization -- Low?Operator Utilization -- Low? Throughput Times (Lead Time) -- HighThroughput Times (Lead Time) -- High

System is Very Flexible, produces many different System is Very Flexible, produces many different types of parts: gears, shafts, pinions, housings, types of parts: gears, shafts, pinions, housings, clamps, etc.clamps, etc.

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Product Line LayoutProduct Line Layout

LatheLathe MillMill GrindGrind

LatheLathe DrillDrill WashWash

LatheLathe SealSeal WashWash

AA

BB

CC

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CharacteristicsCharacteristicsof Product Line Layoutof Product Line Layout

High volume operations, Continuous productionHigh volume operations, Continuous production Specialized capital intensive resourcesSpecialized capital intensive resources Faster processing ratesFaster processing rates Lower inventoriesLower inventories Less unproductive time lost to changeoversLess unproductive time lost to changeovers

Less flexibilityLess flexibility Low resource utilization for low volume Low resource utilization for low volume

products or services.products or services.

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““Production Cell”Production Cell”

Definition:Definition:

A group of functionally dissimilar A group of functionally dissimilar production capabilities located in production capabilities located in physical proximity which are physical proximity which are dedicated to the complete processing dedicated to the complete processing of similar demand requests.of similar demand requests.

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Shaft Cell (Flow-Line)Shaft Cell (Flow-Line)

WorkerS

T

HT

M

G

Cross trained/multifunctional

IN OUT

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Characteristics of Flow-line Characteristics of Flow-line Manufacturing CellsManufacturing Cells

Short Lead-TimesShort Lead-Times Small Backlogs (In-process Inventory)Small Backlogs (In-process Inventory) Reduced Material HandlingReduced Material Handling Improved QualityImproved Quality More Flexible WorkforceMore Flexible Workforce

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Manufacturing Vs. Service Manufacturing Vs. Service CellsCells

Factor Manufacturing Service Production Capabilities

Machines People

Demand Requests

Production Orders for

Parts

Document Processing

Requests

Similar Demand Requests

Production parts with similar required processing steps

Documents with similar required processing steps

Physical

Proximity

All “cell machines”

grouped together in one area of the shop floor

All “cell people”

grouped together in one common office

area.

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Departmental Layout: Departmental Layout: ServiceService

+ + +

+ + +

Data Prep

• ••

• •

Validation

OO

OO

O

Scanning & Verification

X X

X

Sales

Review & TPOS

O

O

Key

Grouping by function, not job

type...

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Tax Type I Cell (Flowline)Tax Type I Cell (Flowline)

Data Prep

Special

ProfilesOne or more multi-skilled personnel in

same area

Pull/Sort

Exceptions

Billing

Scan Data & Verify

Est. Tax

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Characterization of Flow-Characterization of Flow-line Service Cellsline Service Cells

Shorter Lead-TimesShorter Lead-Times Smaller BacklogsSmaller Backlogs Reduced Paper HandlingReduced Paper Handling Improved Quality, Quicker ResponseImproved Quality, Quicker Response More Flexible WorkforceMore Flexible Workforce

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(a) Flexible Staffing and Adjustable Production Rates

1 4

2 3

1st Shift50 pcs/hr

n operator #n

2

1

2nd Shift30 pcs/hr

U-Shaped Layout Pattern for U-Shaped Layout Pattern for Flow Line WorkcellsFlow Line Workcells

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(b) Inter-Linked U-Shaped Cells

Sub-Assembly

Paint

U-Shaped Layout Pattern for U-Shaped Layout Pattern for Flow Line WorkcellsFlow Line Workcells

Wash

Machining

HeatTreat

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LOT vs. CONTINUOUS LOT vs. CONTINUOUS FLOW PROCESSINGFLOW PROCESSING

MACHINE 1 MACHINE 2

Job Batch Setup Process Setup Process

1 100 pcs 60 min 1 min/pc 70 min 0.9 min/pc

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CASE A: LOT PROCESSINGCASE A: LOT PROCESSING

Setup Process Setup Process60 min 100 min 70 min 90 min

MACHINE #1 MACHINE #2

PRODUCTION LEAD TIME=5.33 HRS

M 1 LOT M 2

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CASE B: CONTINUOUS FLOWCASE B: CONTINUOUS FLOW

M 1 100SU=60

90

PLT = 2.67 hrs

PRODUCTION LEAD TIME SAVINGS

M 1 M 2 . . . . .

SU=70

5.33 hrs - 2.67 hrs5.33 hrs

= 50%

0102030405060708090

100

1 2 3 4 5 6 7 8 9

Number of Production Operations

Pro

duct

ion

Lea

d T

ime

Sav

ings

(%

)

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TerminologyTerminology Order: A customer order is a request from a customer for a Order: A customer order is a request from a customer for a

specific quantity of an end item to be delivered by a specific datespecific quantity of an end item to be delivered by a specific date

Job: A set of physical materials that traverse routingsJob: A set of physical materials that traverse routings

Throughput(rate): the average output of a production process per Throughput(rate): the average output of a production process per unit timeunit time

Cycle Time, Flow Time Throughput Time: Average time between Cycle Time, Flow Time Throughput Time: Average time between the release of a job to the completion of a job. the release of a job to the completion of a job.

Manufacturing Lead Time: The time alloted for production of a partManufacturing Lead Time: The time alloted for production of a part

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Four Critical PerspectivesFour Critical Perspectives

Resource PerspectiveResource Perspective

Spatial PerspectiveSpatial Perspective

Transformation PerspectiveTransformation Perspective

Organizational PerspectiveOrganizational Perspective

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ADVANTAGES OF CELLSADVANTAGES OF CELLS

Improved workflowImproved workflow Increased operational flexibilityIncreased operational flexibility Reduced material handlingReduced material handling Improved qualityImproved quality Improved equipment utilizationImproved equipment utilization Facilitates reduced setup times and tooling Facilitates reduced setup times and tooling

costs (Identifies families of parts)costs (Identifies families of parts) Flexible staffing and improved operator Flexible staffing and improved operator

utilizationutilization

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ADVANTAGES OF CELLSADVANTAGES OF CELLS

Improved human relationsImproved human relations Workers respond positively when goals are Workers respond positively when goals are

apparent and attainableapparent and attainable Workers have a greater sense of Workers have a greater sense of

importance (job enlargement)importance (job enlargement) Labor productivity increasesLabor productivity increases Problems are continually revealed and best Problems are continually revealed and best

solved by “Cell Teams!”solved by “Cell Teams!”

JIT Enforced Problem Solving

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ADVANTAGES OF CELLSADVANTAGES OF CELLS

Improved/Simplified Shop Floor ControlImproved/Simplified Shop Floor Control Simplified paperworkSimplified paperwork Less supervision??Less supervision?? Accurate machine and manpower Accurate machine and manpower

requirement analysisrequirement analysis Facilitates Better Quality and “Quicker Facilitates Better Quality and “Quicker

Adjustments”Adjustments” Improved information flowImproved information flow

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DISADVANTAGES OF DISADVANTAGES OF CELLSCELLS Reduced FlexibilityReduced Flexibility Imbalance of machine utilizationImbalance of machine utilization Equipment Cost (Duplication)Equipment Cost (Duplication) Higher Skill/TrainingHigher Skill/Training Relocation CostsRelocation Costs Tooling/SupportTooling/Support Cost of DowntimeCost of Downtime

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DISADVANTAGES OF DISADVANTAGES OF CELLSCELLS Traditional Methods of Cost Justification Traditional Methods of Cost Justification

Don’t WorkDon’t Work Obsolescence of TechnologyObsolescence of Technology Potential of crippling delays due to Potential of crippling delays due to

machine breakdowns, operator machine breakdowns, operator absenteeism,etc.absenteeism,etc.

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Building Lean Production Building Lean Production SystemsSystems Create a subplant or focused factory Create a subplant or focused factory

within the larger factorywithin the larger factory Divide the subplants into processing Divide the subplants into processing

blocksblocks Subdivide processing blocks into cellsSubdivide processing blocks into cells Create corresponding storage,shipping Create corresponding storage,shipping

and receiving facilitiesand receiving facilities

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Ways to focus plants:Ways to focus plants:Business Philosophy and StrategyBusiness Philosophy and Strategy

ProductProduct Group by product typeGroup by product type Organize by product volumeOrganize by product volume Reduce the number of productsReduce the number of products Segregate new productsSegregate new products

ProcessesProcesses Group by process technologyGroup by process technology Reduce the number of technologiesReduce the number of technologies Limit the number of raw materialsLimit the number of raw materials

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QuestionsQuestions