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© 2006 Prentice Hall, Inc. 9 – 1
Layout StrategyLayout Strategy
Chapter9Chapter9
© 2006 Prentice Hall, Inc. 9 – 2
Innovations at McDonald’sInnovations at McDonald’s
Indoor seating (1950s)Indoor seating (1950s) Drive-through window (1970s)Drive-through window (1970s) Adding breakfast to the menu Adding breakfast to the menu
(1980s)(1980s) Adding play areas (1990s)Adding play areas (1990s)
Three out of the four are Three out of the four are layout decisions!layout decisions!
© 2006 Prentice Hall, Inc. 9 – 3
McDonald’s New Kitchen McDonald’s New Kitchen LayoutLayout
Fifth major innovation Fifth major innovation Sandwiches assembled in order Sandwiches assembled in order Elimination of some steps, shortening of Elimination of some steps, shortening of
others others No food prepared ahead except pattyNo food prepared ahead except patty New bun toasting machine and new bun New bun toasting machine and new bun
formulationformulation Repositioning condiment containersRepositioning condiment containers Savings of $100,000,000 per year in food Savings of $100,000,000 per year in food
costscosts
© 2006 Prentice Hall, Inc. 9 – 4
Strategic Importance of Strategic Importance of Layout DecisionsLayout Decisions
The objective of layout strategy The objective of layout strategy is to develop an economic layout is to develop an economic layout
that will meet the firm’s that will meet the firm’s competitive requirementscompetitive requirements
© 2006 Prentice Hall, Inc. 9 – 5
Types of LayoutTypes of Layout
1.1. Office layout Office layout
2.2. Retail layout Retail layout
3.3. Warehouse layoutWarehouse layout
4.4. Fixed-position layoutFixed-position layout
5.5. Process-oriented layoutProcess-oriented layout
6.6. Work cell layout Work cell layout
7.7. Product-oriented layoutProduct-oriented layout
© 2006 Prentice Hall, Inc. 9 – 6
Types of LayoutTypes of Layout
1.1. Office layout - positions workers, Office layout - positions workers, their equipment, and spaces/offices their equipment, and spaces/offices to provide for movement of to provide for movement of informationinformation
2.2. Retail layout - allocates shelf space Retail layout - allocates shelf space and responds to customer behavior and responds to customer behavior
3.3. Warehouse layout - addresses Warehouse layout - addresses trade-offs between space and trade-offs between space and material handlingmaterial handling
© 2006 Prentice Hall, Inc. 9 – 7
Types of LayoutTypes of Layout
4.4. Fixed-position layout - addresses Fixed-position layout - addresses the layout requirements of large, the layout requirements of large, bulky projects such as ships and bulky projects such as ships and buildingsbuildings
5.5. Process-oriented layout - deals with Process-oriented layout - deals with low-volume, high-variety production low-volume, high-variety production (also called job shop or intermittent (also called job shop or intermittent production)production)
© 2006 Prentice Hall, Inc. 9 – 8
Types of LayoutTypes of Layout
6.6. Work cell layout - a special Work cell layout - a special arrangement of machinery and arrangement of machinery and equipment to focus on production of equipment to focus on production of a single product or group of related a single product or group of related productsproducts
7.7. Product-oriented layout - seeks the Product-oriented layout - seeks the best personnel and machine best personnel and machine utilizations in repetitive or utilizations in repetitive or continuous productioncontinuous production
© 2006 Prentice Hall, Inc. 9 – 9
Types of LayoutTypes of Layout
1.1. Office layoutOffice layout
2.2. Retail layout Retail layout
3.3. Warehouse layoutWarehouse layout
4.4. Fixed-position layoutFixed-position layout
5.5. Process-oriented layoutProcess-oriented layout
6.6. Work cell layout Work cell layout
7.7. Product-oriented layoutProduct-oriented layout
© 2006 Prentice Hall, Inc. 9 – 10
Office LayoutOffice Layout
Grouping of workers, their Grouping of workers, their equipment, and spaces to provide equipment, and spaces to provide comfort, safety, and movement of comfort, safety, and movement of informationinformation
Movement of information is main Movement of information is main distinctiondistinction
Typically in state of flux due to Typically in state of flux due to frequent technological changesfrequent technological changes
© 2006 Prentice Hall, Inc. 9 – 11
Relationship ChartRelationship ChartValue Closeness
A Absolutely necessary
E Especially important
I Important
O Ordinary OK
U Unimportant
X Not desirable
President
Chief Technology Officer
Engineer’s area
Secretary
Office entrance
Central files
Equipment cabinet
Photocopy equipment
Storage room
O
UA
X
O
U
A
I
OA
I
O
U
AI
I
A
UO
AU O
UX
O I
U
OII
I
E
EE
E E
1122
3344
5566
77
8899
Figure 9.1Figure 9.1
© 2006 Prentice Hall, Inc. 9 – 12
Types of LayoutTypes of Layout
1.1. Office layout Office layout
2.2. Retail layoutRetail layout
3.3. Warehouse layoutWarehouse layout
4.4. Fixed-position layoutFixed-position layout
5.5. Process-oriented layoutProcess-oriented layout
6.6. Work cell layout Work cell layout
7.7. Product-oriented layoutProduct-oriented layout
© 2006 Prentice Hall, Inc. 9 – 13
Supermarket Retail LayoutSupermarket Retail Layout
ObjectiveObjective is to maximize is to maximize profitability per square foot of profitability per square foot of floor spacefloor space
Sales and profitability vary Sales and profitability vary directly with directly with customer exposurecustomer exposure
© 2006 Prentice Hall, Inc. 9 – 14
Five Helpful Ideas for Five Helpful Ideas for Supermarket LayoutSupermarket Layout
1.1. Locate high-draw items around the Locate high-draw items around the periphery of the storeperiphery of the store
2.2. Use prominent locations for high-impulse Use prominent locations for high-impulse and high-margin itemsand high-margin items
3.3. Distribute power items to both sides of Distribute power items to both sides of an aisle and disperse them to increase an aisle and disperse them to increase viewing of other itemsviewing of other items
4.4. Use end-aisle locationsUse end-aisle locations
5.5. Convey mission of store through careful Convey mission of store through careful positioning of lead-off departmentpositioning of lead-off department
© 2006 Prentice Hall, Inc. 9 – 15
Retail SlottingRetail Slotting Manufacturers pay fees to retailers Manufacturers pay fees to retailers
to get the retailers to display (slot) to get the retailers to display (slot) their producttheir product
Contributing factorsContributing factors Limited shelf spaceLimited shelf space
An increasing number of new An increasing number of new productsproducts
Better information about sales Better information about sales through POS data collectionthrough POS data collection
Closer control of inventoryCloser control of inventory
© 2006 Prentice Hall, Inc. 9 – 16
Retail Store Shelf Space Retail Store Shelf Space PlanogramPlanogram
Computerized Computerized tool for shelf-tool for shelf-space space managementmanagement
Generated from Generated from store’s scanner store’s scanner data on salesdata on sales
Often supplied Often supplied by manufacturerby manufacturer
5 facings5 facings
Sh
amp
oo
Sh
amp
oo
Sh
amp
oo
Sh
amp
oo
Sh
amp
oo
Co
nd
ition
er
Co
nd
ition
er
Sh
amp
oo
Sh
amp
oo
Sh
amp
oo
Sh
amp
oo
Co
nd
ition
er
2 ft.2 ft.
© 2006 Prentice Hall, Inc. 9 – 17
Types of LayoutTypes of Layout
1.1. Office layout Office layout
2.2. Retail layout Retail layout
3.3. Warehouse layoutWarehouse layout
4.4. Fixed-position layoutFixed-position layout
5.5. Process-oriented layoutProcess-oriented layout
6.6. Work cell layout Work cell layout
7.7. Product-oriented layoutProduct-oriented layout
© 2006 Prentice Hall, Inc. 9 – 18
Warehousing and Storage Warehousing and Storage LayoutsLayouts
ObjectiveObjective is to optimize trade-offs is to optimize trade-offs between handling costs and costs between handling costs and costs associated with warehouse spaceassociated with warehouse space
Maximize the total “cube” of the Maximize the total “cube” of the warehouse – utilize its full volume warehouse – utilize its full volume while maintaining low material while maintaining low material handling costshandling costs
© 2006 Prentice Hall, Inc. 9 – 19
Warehousing and Storage Warehousing and Storage LayoutsLayouts
Warehouse density tends to vary Warehouse density tends to vary inversely with the number of inversely with the number of different items storeddifferent items stored
Automated Storage and Retrieval Automated Storage and Retrieval Systems (ASRS) can significantly Systems (ASRS) can significantly improve warehouse productivityimprove warehouse productivity
Dock location is a key design Dock location is a key design elementelement
© 2006 Prentice Hall, Inc. 9 – 20
Cross-DockingCross-Docking
Materials are moved directly from Materials are moved directly from receiving to shipping and are not receiving to shipping and are not placed in storage in the placed in storage in the warehousewarehouse
Requires tight scheduling and Requires tight scheduling and accurate shipments, typically accurate shipments, typically with bar code identificationwith bar code identification
© 2006 Prentice Hall, Inc. 9 – 21
Shipping and receiving docks
Office
Cu
sto
miz
atio
n
Conveyor
Storage racks
Staging
Warehouse LayoutWarehouse LayoutTraditional LayoutTraditional Layout
© 2006 Prentice Hall, Inc. 9 – 22
Warehouse LayoutWarehouse LayoutCross-Docking LayoutCross-Docking Layout
Shipping and receiving docks
Off
ice
Shipping and receiving docks
© 2006 Prentice Hall, Inc. 9 – 23
Types of LayoutTypes of Layout
1.1. Office layout Office layout
2.2. Retail layout Retail layout
3.3. Warehouse layoutWarehouse layout
4.4. Fixed-position layoutFixed-position layout
5.5. Process-oriented layoutProcess-oriented layout
6.6. Work cell layout Work cell layout
7.7. Product-oriented layoutProduct-oriented layout
© 2006 Prentice Hall, Inc. 9 – 24
Fixed-Position LayoutFixed-Position Layout
Product remains in one place Product remains in one place
Workers and equipment come to Workers and equipment come to sitesite
Complicating factorsComplicating factors Limited space at siteLimited space at site
Different materials required at Different materials required at different stages of the projectdifferent stages of the project
Volume of materials needed is Volume of materials needed is dynamicdynamic
© 2006 Prentice Hall, Inc. 9 – 25
Types of LayoutTypes of Layout
1.1. Office layout Office layout
2.2. Retail layout Retail layout
3.3. Warehouse layoutWarehouse layout
4.4. Fixed-position layoutFixed-position layout
5.5. Process-oriented layoutProcess-oriented layout
6.6. Work cell layout Work cell layout
7.7. Product-oriented layoutProduct-oriented layout
© 2006 Prentice Hall, Inc. 9 – 26
Process-Oriented LayoutProcess-Oriented Layout
Like machines and equipment are Like machines and equipment are grouped togethergrouped together
Flexible and capable of handling a Flexible and capable of handling a wide variety of products or wide variety of products or servicesservices
Scheduling can be difficult and Scheduling can be difficult and setup, material handling, and labor setup, material handling, and labor costs can be highcosts can be high
© 2006 Prentice Hall, Inc. 9 – 27
Surgery
Radiology
ER triage room
ER Beds Pharmacy
Emergency room admissions
Billing/exit
Laboratories
Process-Oriented LayoutProcess-Oriented Layout
Patient A - broken leg
Patient B - erratic heart pacemaker
Figure 9.3Figure 9.3
© 2006 Prentice Hall, Inc. 9 – 28
Process-Oriented LayoutProcess-Oriented Layout
Arrange work centers so as to Arrange work centers so as to minimizeminimize the costs of material the costs of material handlinghandling
Basic Basic cost elementscost elements are are Number of loads (or people) moving Number of loads (or people) moving
between centersbetween centers
Distance loads (or people) move Distance loads (or people) move between centersbetween centers
© 2006 Prentice Hall, Inc. 9 – 29
Process-Oriented LayoutProcess-Oriented Layout
Minimize cost = Minimize cost = ∑ ∑∑ ∑ X Xijij C Cijij
nn
i i = 1= 1
nn
j j = 1= 1
wherewhere nn == total number of total number of work centers or departmentswork centers or departments
i, ji, j == individual individual departmentsdepartments
XXijij == number of loads number of loads moved from department i to moved from department i to department jdepartment j
CCijij == cost to move a load cost to move a load between department i and between department i and department jdepartment j
© 2006 Prentice Hall, Inc. 9 – 30
Process Layout ExampleProcess Layout Example
1.1. Construct a “from-to matrix”Construct a “from-to matrix”
2.2. Determine the space requirementsDetermine the space requirements
3.3. Develop an initial schematic diagramDevelop an initial schematic diagram
4.4. Determine the cost of this layout Determine the cost of this layout
5.5. Try to improve the layoutTry to improve the layout
6.6. Prepare a detailed plan Prepare a detailed plan
Arrange six departments in a factory to Arrange six departments in a factory to minimize the material handling costs. minimize the material handling costs. Each department is 20 x 20 feet and the Each department is 20 x 20 feet and the building is 60 feet long and 40 feet wide.building is 60 feet long and 40 feet wide.
© 2006 Prentice Hall, Inc. 9 – 31
DepartmentDepartment AssemblyAssembly PaintingPainting MachineMachine ReceivingReceiving ShippingShipping TestingTesting(1)(1) (2)(2) Shop (3)Shop (3) (4)(4) (5)(5) (6)(6)
Assembly (1)Assembly (1)
Painting (2)Painting (2)
Machine Shop (3)Machine Shop (3)
Receiving (4)Receiving (4)
Shipping (5)Shipping (5)
Testing (6)Testing (6)
Number of loads per weekNumber of loads per week
50 100 0 0 20
30 50 10 0
20 0 100
50 0
0
Process Layout ExampleProcess Layout Example
Figure 9.4Figure 9.4
© 2006 Prentice Hall, Inc. 9 – 32
Room 1Room 1 Room 2Room 2 Room 3Room 3
Room 4Room 4 Room 5Room 5 Room 6Room 660’60’
40’40’
Process Layout ExampleProcess Layout Example
Receiving Shipping TestingDepartment Department Department
(4) (5) (6)
Figure 9.5Figure 9.5
Assembly Painting Machine ShopDepartment Department Department
(1) (2) (3)
© 2006 Prentice Hall, Inc. 9 – 33
Process Layout ExampleProcess Layout Example
Cost Cost == $50$50 ++ $200$200 ++ $40$40(1 and 2)(1 and 2) (1 and 3)(1 and 3) (1 and 6)(1 and 6)
++ $30$30 ++ $50$50 ++ $10$10(2 and 3)(2 and 3) (2 and 4)(2 and 4) (2 and 5)(2 and 5)
++ $40$40 ++ $100$100 ++ $50$50(3 and 4)(3 and 4) (3 and 6)(3 and 6) (4 and 5)(4 and 5)
= $570= $570
Cost = Cost = ∑ ∑∑ ∑ X Xijij C Cijij
nn
i i = 1= 1
nn
j j = 1= 1
© 2006 Prentice Hall, Inc. 9 – 34
100100
5050
2020
5050
5050
20201010
100100
3030
Process Layout ExampleProcess Layout Example
Interdepartmental Flow GraphInterdepartmental Flow Graph
1 2 3
4 5 6
Figure 9.6Figure 9.6
© 2006 Prentice Hall, Inc. 9 – 35
Process Layout ExampleProcess Layout Example
Cost Cost == $50$50 ++ $100$100 ++ $20$20(1 and 2)(1 and 2) (1 and 3)(1 and 3) (1 and 6)(1 and 6)
++ $60$60 ++ $50$50 ++ $10$10(2 and 3)(2 and 3) (2 and 4)(2 and 4) (2 and 5)(2 and 5)
++ $40$40 ++ $100$100 ++ $50$50(3 and 4)(3 and 4) (3 and 6)(3 and 6) (4 and 5)(4 and 5)
= $480= $480
Cost = Cost = ∑ ∑∑ ∑ X Xijij C Cijij
nn
i i = 1= 1
nn
j j = 1= 1
© 2006 Prentice Hall, Inc. 9 – 36
Process Layout ExampleProcess Layout Example
3030
5050
1010
5050
50502020
5050 100100
100100
Interdepartmental Flow GraphInterdepartmental Flow Graph
2 1 3
4 5 6
Figure 9.7Figure 9.7
© 2006 Prentice Hall, Inc. 9 – 37
Room 1Room 1 Room 2Room 2 Room 3Room 3
Room 4Room 4 Room 5Room 5 Room 6Room 660’60’
40’40’
Process Layout ExampleProcess Layout Example
Receiving Shipping TestingDepartment Department Department
(4) (5) (6)
Figure 9.8Figure 9.8
Painting Assembly Machine ShopDepartment Department Department
(2) (1) (3)
© 2006 Prentice Hall, Inc. 9 – 38
Types of LayoutTypes of Layout
1.1. Office layout Office layout
2.2. Retail layout Retail layout
3.3. Warehouse layoutWarehouse layout
4.4. Fixed-position layoutFixed-position layout
5.5. Process-oriented layoutProcess-oriented layout
6.6. Work cell layoutWork cell layout
7.7. Product-oriented layoutProduct-oriented layout
© 2006 Prentice Hall, Inc. 9 – 39
Work CellsWork Cells
Reorganizes people and machines Reorganizes people and machines into groups to focus on single into groups to focus on single products or product groupsproducts or product groups
Group technology identifies Group technology identifies products that have similar products that have similar characteristics for particular cellscharacteristics for particular cells
Volume must justify cellsVolume must justify cells
Cells can be reconfigured as Cells can be reconfigured as designs or volume changesdesigns or volume changes
© 2006 Prentice Hall, Inc. 9 – 40
Advantages of Work CellsAdvantages of Work Cells
1.1. Reduced work-in-process inventoryReduced work-in-process inventory
2.2. Less floor space requiredLess floor space required
3.3. Reduced raw material and finished Reduced raw material and finished goods inventorygoods inventory
4.4. Reduced direct laborReduced direct labor
5.5. Heightened sense of employee Heightened sense of employee participationparticipation
6.6. Increased use of equipment and Increased use of equipment and machinerymachinery
7.7. Reduced investment in machinery Reduced investment in machinery and equipmentand equipment
© 2006 Prentice Hall, Inc. 9 – 41
Improving Layouts Using Improving Layouts Using Work CellsWork Cells
Current layout - workers in Current layout - workers in small closed areas. small closed areas. Cannot increase output Cannot increase output without a third worker and without a third worker and third set of equipment.third set of equipment. Improved layout - cross-trained Improved layout - cross-trained
workers can assist each other. workers can assist each other. May be able to add a third worker May be able to add a third worker as additional output is needed.as additional output is needed.
Figure 9.10 (a)Figure 9.10 (a)
© 2006 Prentice Hall, Inc. 9 – 42
Improving Layouts Using Improving Layouts Using Work CellsWork Cells
Current layout - straight Current layout - straight lines make it hard to balance lines make it hard to balance tasks because work may not tasks because work may not be divided evenlybe divided evenly
Improved layout - in U Improved layout - in U shape, workers have better shape, workers have better access. Four cross-trained access. Four cross-trained workers were reduced.workers were reduced.
Figure 9.10 (b)Figure 9.10 (b)
U-shaped line may reduce employee movement and space requirements while enhancing communication, reducing the number of workers, and facilitating inspection
© 2006 Prentice Hall, Inc. 9 – 43
Requirements of Work CellsRequirements of Work Cells
1.1. Identification of families of productsIdentification of families of products
2.2. A high level of training and A high level of training and flexibility on the part of employeesflexibility on the part of employees
3.3. Either staff support or flexible, Either staff support or flexible, imaginative employees to establish imaginative employees to establish work cells initiallywork cells initially
4.4. Test (poka-yoke) at each station in Test (poka-yoke) at each station in the cellthe cell
© 2006 Prentice Hall, Inc. 9 – 44
Types of LayoutTypes of Layout
1.1. Office layout Office layout
2.2. Retail layout Retail layout
3.3. Warehouse layoutWarehouse layout
4.4. Fixed-position layoutFixed-position layout
5.5. Process-oriented layoutProcess-oriented layout
6.6. Work cell layout Work cell layout
7.7. Product-oriented layoutProduct-oriented layout
© 2006 Prentice Hall, Inc. 9 – 45
Repetitive and Product-Repetitive and Product-Oriented LayoutOriented Layout
Volume is adequate for high equipment Volume is adequate for high equipment utilizationutilization
Product demand is stable enough to justify high Product demand is stable enough to justify high investment in specialized equipmentinvestment in specialized equipment
Product is standardized or approaching a phase Product is standardized or approaching a phase of life cycle that justifies investment of life cycle that justifies investment
Supplies of raw materials and components are Supplies of raw materials and components are adequate and of uniform qualityadequate and of uniform quality
Organized around products or families of Organized around products or families of similar high-volume, low-variety productssimilar high-volume, low-variety products
© 2006 Prentice Hall, Inc. 9 – 46
Product-Oriented LayoutsProduct-Oriented Layouts Fabrication lineFabrication line
Builds components on a series of machinesBuilds components on a series of machines Machine-pacedMachine-paced Require mechanical or engineering changes Require mechanical or engineering changes
to balanceto balance Assembly lineAssembly line
Puts fabricated parts together at a series of Puts fabricated parts together at a series of workstationsworkstations
Paced by work tasksPaced by work tasks Balanced by moving tasksBalanced by moving tasks
Both types of lines must be balanced so that the Both types of lines must be balanced so that the time to perform the work at each station is the sametime to perform the work at each station is the same
© 2006 Prentice Hall, Inc. 9 – 47
Product-Oriented LayoutsProduct-Oriented Layouts
1.1. Low variable cost per unitLow variable cost per unit
2.2. Low material handling costsLow material handling costs
3.3. Reduced work-in-process inventoriesReduced work-in-process inventories
4.4. Easier training and supervisionEasier training and supervision
5.5. Rapid throughputRapid throughput
AdvantagesAdvantages
1.1. High volume is requiredHigh volume is required
2.2. Work stoppage at any point ties up the Work stoppage at any point ties up the whole operationwhole operation
3.3. Lack of flexibility in product or production Lack of flexibility in product or production ratesrates
DisadvantagesDisadvantages
© 2006 Prentice Hall, Inc. 9 – 48
Assembly-Line BalancingAssembly-Line Balancing
Objective is to Objective is to minimize the imbalanceminimize the imbalance between machines or personnel while between machines or personnel while meeting required outputmeeting required output
Starts with the precedence Starts with the precedence relationshipsrelationships
1.1. Determine cycle timeDetermine cycle time
2.2. Calculate theoretical minimum number Calculate theoretical minimum number of workstationsof workstations
3.3. Balance the line by assigning specific Balance the line by assigning specific tasks to workstationstasks to workstations
© 2006 Prentice Hall, Inc. 9 – 49
Copier ExampleCopier Example
This means that This means that tasks B and E tasks B and E cannot be done cannot be done until task A has until task A has been completedbeen completed
PerformancePerformance Task Must FollowTask Must FollowTimeTime Task ListedTask Listed
TaskTask (minutes)(minutes) BelowBelow
AA 1010 ——BB 1111 AACC 55 BBDD 44 BBEE 1212 AAFF 33 C, DC, DGG 77 FFHH 1111 EEII 33 G, HG, H
Total time Total time 6666
© 2006 Prentice Hall, Inc. 9 – 50
Copier ExampleCopier Example
PerformancePerformance Task Must FollowTask Must FollowTimeTime Task ListedTask Listed
TaskTask (minutes)(minutes) BelowBelow
AA 1010 ——BB 1111 AACC 55 BBDD 44 BBEE 1212 AAFF 33 C, DC, DGG 77 FFHH 1111 EEII 33 G, HG, H
Total time Total time 6666 I
GF
C
D
H
B
E
A
10
1112
5
4 3
711 3
Figure 9.13
© 2006 Prentice Hall, Inc. 9 – 51
I
GF
C
D
H
B
E
A
10
1112
5
4 3
711 3
Figure 9.13
PerformancePerformance Task Must FollowTask Must FollowTimeTime Task ListedTask Listed
TaskTask (minutes)(minutes) BelowBelow
AA 1010 ——BB 1111 AACC 55 BBDD 44 BBEE 1212 AAFF 33 C, DC, DGG 77 FFHH 1111 EEII 33 G, HG, H
Total time Total time 6666
Copier ExampleCopier Example480 available
mins per day40 units required
Cycle time =
Production time available per day
Units required per day
= 480 / 40= 12 minutes per unit
Minimum number of
workstations=
∑ Time for task i
Cycle time
n
i = 1
= 66 / 12= 5.5 or 6 stations
© 2006 Prentice Hall, Inc. 9 – 52
I
GF
C
D
H
B
E
A
10
1112
5
4 3
711 3
Figure 9.13
PerformancePerformance Task Must FollowTask Must FollowTimeTime Task ListedTask Listed
TaskTask (minutes)(minutes) BelowBelow
AA 1010 ——BB 1111 AACC 55 BBDD 44 BBEE 1212 AAFF 33 C, DC, DGG 77 FFHH 1111 EEII 33 G, HG, H
Total time Total time 6666
Copier ExampleCopier Example480 available
mins per day40 units required
Cycle time = 12 mins
Minimum workstations = 5.5 or 6
Line-Balancing Heuristics
1. Longest task time Choose the available task with the longest task time
2. Most following tasks Choose the available task with the largest number of following tasks
3. Ranked positional weight
Choose the available task for which the sum of following task times is the longest
4. Shortest task time Choose the available task with the shortest task time
5. Least number of following tasks
Choose the available task with the least number of following tasks
Table 9.4
© 2006 Prentice Hall, Inc. 9 – 53
480 available mins per day
40 units required
Cycle time = 12 mins
Minimum workstations = 5.5 or 6
PerformancePerformance Task Must FollowTask Must FollowTimeTime Task ListedTask Listed
TaskTask (minutes)(minutes) BelowBelow
AA 1010 ——BB 1111 AACC 55 BBDD 44 BBEE 1212 AAFF 33 C, DC, DGG 77 FFHH 1111 EEII 33 G, HG, H
Total time Total time 6666
Copier ExampleCopier Example
I
GF
H
C
D
B
E
A
10 11
12
5
4
3 7
11
3
Station 1
Station 2
Station 3
Station 5
Station 4
Station 6
Figure 9.14
© 2006 Prentice Hall, Inc. 9 – 54
PerformancePerformance Task Must FollowTask Must FollowTimeTime Task ListedTask Listed
TaskTask (minutes)(minutes) BelowBelow
AA 1010 ——BB 1111 AACC 55 BBDD 44 BBEE 1212 AAFF 33 C, DC, DGG 77 FFHH 1111 EEII 33 G, HG, H
Total time Total time 6666
Copier ExampleCopier Example480 available
mins per day40 units required
Cycle time = 12 mins
Minimum workstations = 5.5 or 6
Efficiency =∑ Task times
(actual number of workstations) x (largest cycle time)
= 66 minutes / (6 stations) x (12 minutes)
= 91.7%