1 JMP 5023 OPERATIONS & TECHNOLOGY MANAGEMENT INTRODUCTION TO OPERATIONS MANAGEMENT.
Operations Management
description
Transcript of Operations Management
© 2008 Prentice Hall, Inc. 9 – 1
Operations ManagementOperations ManagementChapter 9 – Chapter 9 – Layout StrategiesLayout Strategies
© 2008 Prentice Hall, Inc. 9 – 2
Strategic Importance of Strategic Importance of Layout DecisionsLayout Decisions
The objective of layout strategy The objective of layout strategy is to develop a cost-effective is to develop a cost-effective layout that will meet a firm’s layout that will meet a firm’s
competitive needscompetitive needs
© 2008 Prentice Hall, Inc. 9 – 3
Layout Design Layout Design ConsiderationsConsiderations
Higher utilization of space, equipment, Higher utilization of space, equipment, and peopleand people
Improved flow of information, materials, Improved flow of information, materials, or peopleor people
Improved employee morale and safer Improved employee morale and safer working conditionsworking conditions
Improved customer/client interactionImproved customer/client interaction
FlexibilityFlexibility
© 2008 Prentice Hall, Inc. 9 – 4
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
© 2008 Prentice Hall, Inc. 9 – 5
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 trade-Warehouse layout: Addresses trade-offs between space and material offs between space and material handlinghandling
© 2008 Prentice Hall, Inc. 9 – 6
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)
© 2008 Prentice Hall, Inc. 9 – 7
Types of LayoutTypes of Layout
6.6. Work cell layout: Arranges Work cell layout: Arranges machinery and equipment to focus machinery and equipment to focus on production of a single product or on production of a single product or group of related productsgroup of related products
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
© 2008 Prentice Hall, Inc. 9 – 8
Good Layouts ConsiderGood Layouts Consider
1.1. Material handling equipmentMaterial handling equipment
2.2. Capacity and space requirementsCapacity and space requirements
3.3. Environment and aestheticsEnvironment and aesthetics
4.4. Flows of informationFlows of information
5.5. Cost of moving between various Cost of moving between various work areaswork areas
© 2008 Prentice Hall, Inc. 9 – 9
Office LayoutOffice Layout
Grouping of workers, their equipment, Grouping of workers, their equipment, and spaces to provide comfort, and spaces to provide comfort, safety, and movement of informationsafety, and movement of information
Movement of Movement of information is main information is main distinctiondistinction
Typically in state of Typically in state of flux due to frequent flux due to frequent technological technological changeschanges
© 2008 Prentice Hall, Inc. 9 – 10
Relationship ChartRelationship Chart
Figure 9.1Figure 9.1
© 2008 Prentice Hall, Inc. 9 – 11
Supermarket Retail LayoutSupermarket Retail Layout
Objective is to maximize Objective 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 customer exposuredirectly with customer exposure
© 2008 Prentice Hall, Inc. 9 – 12
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
© 2008 Prentice Hall, Inc. 9 – 13
Store LayoutStore Layout
Figure 9.2Figure 9.2
© 2008 Prentice Hall, Inc. 9 – 14
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
© 2008 Prentice Hall, Inc. 9 – 15
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.
© 2008 Prentice Hall, Inc. 9 – 16
ServicescapesServicescapes Ambient conditions - background Ambient conditions - background
characteristics such as lighting, sound, characteristics such as lighting, sound, smell, and temperaturesmell, and temperature
Spatial layout and functionality - which Spatial layout and functionality - which involve customer involve customer circulation path planning, circulation path planning, aisle characteristics, and aisle characteristics, and product groupingproduct grouping
Signs, symbols, and Signs, symbols, and artifacts - characteristics artifacts - characteristics of building design that of building design that carry social significancecarry social significance
© 2008 Prentice Hall, Inc. 9 – 17
Warehousing and Storage Warehousing and Storage LayoutsLayouts
Objective is to optimize trade-offs Objective 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
© 2008 Prentice Hall, Inc. 9 – 18
Warehousing and Storage Warehousing and Storage LayoutsLayouts
All costs associated with the transactionAll costs associated with the transaction Incoming transportIncoming transport
StorageStorage
Finding and moving materialFinding and moving material
Outgoing transportOutgoing transport
Equipment, people, material, supervision, Equipment, people, material, supervision, insurance, depreciationinsurance, depreciation
Minimize damage and spoilageMinimize damage and spoilage
Material Handling CostsMaterial Handling Costs
© 2008 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 different inversely with the number of different items storeditems stored
Automated Storage and Automated Storage and Retrieval Systems (ASRSs) Retrieval Systems (ASRSs) can significantly improve can significantly improve warehouse productivity by warehouse productivity by an estimated 500%an estimated 500%
Dock location is a key Dock location is a key design elementdesign element
© 2008 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 placed in storage in the warehousein the warehouse
Requires tight Requires tight scheduling and scheduling and accurate shipments, accurate shipments, bar code or RFIDbar code or RFIDidentification used foridentification used foradvanced shipmentadvanced shipmentnotification as materialsnotification as materialsare unloadedare unloaded
© 2008 Prentice Hall, Inc. 9 – 21
Random StockingRandom Stocking Typically requires automatic identification Typically requires automatic identification
systems (AISs) and effective information systems (AISs) and effective information systemssystems
Random assignment of stocking locations Random assignment of stocking locations allows more efficient use of spaceallows more efficient use of space
Key tasksKey tasks
1.1. Maintain list of open locationsMaintain list of open locations
2.2. Maintain accurate recordsMaintain accurate records
3.3. Sequence items to minimize travel, pick timeSequence items to minimize travel, pick time
4.4. Combine picking ordersCombine picking orders
5.5. Assign classes of items to particular areasAssign classes of items to particular areas
© 2008 Prentice Hall, Inc. 9 – 22
CustomizingCustomizing
Value-added activities performed at Value-added activities performed at the warehousethe warehouse
Enable low cost and rapid response Enable low cost and rapid response strategiesstrategies Assembly of componentsAssembly of components
Loading softwareLoading software
RepairsRepairs
Customized labeling and packagingCustomized labeling and packaging
© 2008 Prentice Hall, Inc. 9 – 23
Shipping and receiving docks
Office
Cu
sto
miz
atio
n
Conveyor
Storage racks
Staging
Warehouse LayoutWarehouse LayoutTraditional LayoutTraditional Layout
© 2008 Prentice Hall, Inc. 9 – 24
Warehouse LayoutWarehouse LayoutCross-Docking LayoutCross-Docking Layout
Shipping and receiving docks
Off
ice
Shipping and receiving docks
© 2008 Prentice Hall, Inc. 9 – 25
Fixed-Position LayoutFixed-Position Layout
Product remains in one place Product remains in one place
Workers and equipment come to siteWorkers and equipment come to site
Complicating factorsComplicating factorsLimited space at siteLimited space at site
Different materials Different materials required at different required at different stages of the projectstages of the project
Volume of materials Volume of materials needed is dynamicneeded is dynamic
© 2008 Prentice Hall, Inc. 9 – 26
Alternative StrategyAlternative Strategy
As much of the project as possible As much of the project as possible is completed off-site in a product-is completed off-site in a product-oriented facilityoriented facility
This can This can significantly significantly improve efficiency improve efficiency but is only but is only possible when possible when multiple similar multiple similar units need to be createdunits need to be created
© 2008 Prentice Hall, Inc. 9 – 27
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
© 2008 Prentice Hall, Inc. 9 – 28
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
© 2008 Prentice Hall, Inc. 9 – 29
Process-Oriented LayoutProcess-Oriented Layout
Arrange work centers so as to Arrange work centers so as to minimize the costs of material minimize the costs of material handlinghandling
Basic cost elements areBasic cost elements 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
© 2008 Prentice Hall, Inc. 9 – 30
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
© 2008 Prentice Hall, Inc. 9 – 31
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.
© 2008 Prentice Hall, Inc. 9 – 32
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
© 2008 Prentice Hall, Inc. 9 – 33
Area 1Area 1 Area 2Area 2 Area 3Area 3
Area 4Area 4 Area 5Area 5 Area 6Area 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)
© 2008 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
© 2008 Prentice Hall, Inc. 9 – 35
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
© 2008 Prentice Hall, Inc. 9 – 36
Process Layout ExampleProcess Layout Example
3030
5050
1010
5050
50502020
5050 100100
100100
Revised Interdepartmental Flow GraphRevised Interdepartmental Flow Graph
2 1 3
4 5 6
Figure 9.7Figure 9.7
© 2008 Prentice Hall, Inc. 9 – 37
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
© 2008 Prentice Hall, Inc. 9 – 38
Area 1Area 1 Area 2Area 2 Area 3Area 3
Area 4Area 4 Area 5Area 5 Area 6Area 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)
© 2008 Prentice Hall, Inc. 9 – 39
Computer SoftwareComputer Software
Graphical approach only works for Graphical approach only works for small problemssmall problems
Computer programs are available to Computer programs are available to solve bigger problemssolve bigger problems CRAFTCRAFT
ALDEPALDEP
CORELAPCORELAP
Factory FlowFactory Flow
© 2008 Prentice Hall, Inc. 9 – 40
CRAFT ExampleCRAFT Example
11 22 33 44 55 66
11 A A A A B B
22 A A A A B B
33 D D D D D D
44 C C D D D D
55 F F F F F D
66 E E E E E D
PATTERNPATTERN
TOTAL COST 20,100TOTAL COST 20,100EST. COST REDUCTION .00EST. COST REDUCTION .00ITERATION 0ITERATION 0
(a)(a)
11 22 33 44 55 66
11 D D D D B B
22 D D D D B B
33 D D D E E E
44 C C D E E F
55 A A A A A F
66 A A A F F F
PATTERNPATTERN
TOTAL COST 14,390TOTAL COST 14,390EST. COST REDUCTION 70.EST. COST REDUCTION 70.ITERATION 3ITERATION 3
(b)(b) Figure 9.9Figure 9.9
© 2008 Prentice Hall, Inc. 9 – 41
Computer SoftwareComputer Software
Three dimensional visualization Three dimensional visualization software allows managers to view software allows managers to view possible layouts and assess process, possible layouts and assess process, material material handling, handling, efficiency, efficiency, and safety and safety issuesissues
© 2008 Prentice Hall, Inc. 9 – 42
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
© 2008 Prentice Hall, Inc. 9 – 43
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
© 2008 Prentice Hall, Inc. 9 – 44
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)
© 2008 Prentice Hall, Inc. 9 – 45
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
© 2008 Prentice Hall, Inc. 9 – 46
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, flexibility A high level of training, flexibility and empowerment of employeesand empowerment of employees
3.3. Being self-contained, with its own Being self-contained, with its own equipment and resourcesequipment and resources
4.4. Test (poka-yoke) at each station in Test (poka-yoke) at each station in the cellthe cell
© 2008 Prentice Hall, Inc. 9 – 47
Staffing and Balancing Staffing and Balancing Work CellsWork Cells
Determine the takt timeDetermine the takt time
Takt time =Takt time =Total work time availableTotal work time available
Units requiredUnits required
Determine the number Determine the number of operators requiredof operators required
Workers required =Workers required =Total operation time requiredTotal operation time required
Takt timeTakt time
© 2008 Prentice Hall, Inc. 9 – 48
Staffing Work Cells ExampleStaffing Work Cells Example
600 600 Mirrors per day requiredMirrors per day requiredMirror production scheduled for Mirror production scheduled for 88 hours per day hours per dayFrom a work balance chart From a work balance chart
total operation time total operation time = 140= 140 seconds seconds
Sta
nd
ard
tim
e re
qu
ired
Sta
nd
ard
tim
e re
qu
ired
OperationsOperations
AssembleAssemble PaintPaint TestTest LabelLabel Pack forPack forshipmentshipment
6060
5050
4040
3030
2020
1010
00
© 2008 Prentice Hall, Inc. 9 – 49
Staffing Work Cells ExampleStaffing Work Cells Example
600 600 Mirrors per day requiredMirrors per day requiredMirror production scheduled for Mirror production scheduled for 88 hours per day hours per dayFrom a work balance chart From a work balance chart
total operation time total operation time = 140= 140 seconds seconds
Takt timeTakt time = = (8(8 hrs hrs x 60x 60 mins mins) / 600) / 600 units units = .8= .8 mins mins = 48= 48 seconds seconds
Workers requiredWorkers required ==Total operation time requiredTotal operation time required
Takt timeTakt time
= 140 / 48 = 2.91= 140 / 48 = 2.91
© 2008 Prentice Hall, Inc. 9 – 50
Work Balance ChartsWork Balance Charts
Used for evaluating operation Used for evaluating operation times in work cellstimes in work cells
Can help identify bottleneck Can help identify bottleneck operationsoperations
Flexible, cross-trained employees Flexible, cross-trained employees can help address labor bottleneckscan help address labor bottlenecks
Machine bottlenecks may require Machine bottlenecks may require other approachesother approaches
© 2008 Prentice Hall, Inc. 9 – 51
Focused Work Center and Focused Work Center and Focused FactoryFocused Factory
Focused Work CenterFocused Work Center Identify a large family of similar products Identify a large family of similar products
that have a large and stable demandthat have a large and stable demand
Moves production from a general-purpose, Moves production from a general-purpose, process-oriented facility to a large work cellprocess-oriented facility to a large work cell
Focused FactoryFocused Factory A focused work cell in a separate facilityA focused work cell in a separate facility
May be focused by product line, layout, May be focused by product line, layout, quality, new product introduction, flexibility, quality, new product introduction, flexibility, or other requirementsor other requirements
© 2008 Prentice Hall, Inc. 9 – 52
Focused Work Center and Focused Work Center and Focused FactoryFocused Factory
Table 9.2Table 9.2
Work CellWork Cell Focused Work CenterFocused Work Center Focused FactoryFocused Factory
A work cell is a A work cell is a temporary product-temporary product-oriented arrangement oriented arrangement of machines and of machines and personnel in what is personnel in what is ordinarily a process-ordinarily a process-oriented facility.oriented facility.
A focused work center is A focused work center is a permanent product-a permanent product-oriented arrangement oriented arrangement of machines and of machines and personnel in what is personnel in what is ordinarily a process-ordinarily a process-oriented facility.oriented facility.
A focused factory is a A focused factory is a permanent facility to permanent facility to produce a product or produce a product or component in a component in a product-oriented product-oriented facility. Many focused facility. Many focused factories currently factories currently being built were being built were originally part of a originally part of a process-oriented process-oriented facility.facility.
Example: A job shop Example: A job shop with machinery and with machinery and personnel rearranged personnel rearranged to produce 300 unique to produce 300 unique control panels.control panels.
Example: Pipe bracket Example: Pipe bracket manufacturing at a manufacturing at a shipyard.shipyard.
Example: A plant to Example: A plant to produce window produce window mechanism for mechanism for automobiles.automobiles.
© 2008 Prentice Hall, Inc. 9 – 53
Repetitive and Product-Repetitive and Product-Oriented LayoutOriented Layout
1.1. Volume is adequate for high equipment Volume is adequate for high equipment utilizationutilization
2.2. Product demand is stable enough to justify high Product demand is stable enough to justify high investment in specialized equipmentinvestment in specialized equipment
3.3. 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
4.4. 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
© 2008 Prentice Hall, Inc. 9 – 54
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
© 2008 Prentice Hall, Inc. 9 – 55
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
© 2008 Prentice Hall, Inc. 9 – 56
McDonald’s Assembly LineMcDonald’s Assembly Line
Figure 9.12Figure 9.12
© 2008 Prentice Hall, Inc. 9 – 57
Disassembly LinesDisassembly Lines
• Disassembly is being considered in Disassembly is being considered in new product designsnew product designs
• ““Green” issues and recycling Green” issues and recycling standards are important considerationstandards are important consideration
• Automotive Automotive disassembly is disassembly is the 16the 16thth largest largest industry in industry in the USthe US
© 2008 Prentice Hall, Inc. 9 – 58
Assembly-Line BalancingAssembly-Line Balancing
Objective is to minimize the imbalance Objective is to minimize 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 Calculate theoretical minimum number of minimum number of workstationsworkstations
3.3. Balance the line by Balance the line by assigning specific assigning specific tasks to workstationstasks to workstations
© 2008 Prentice Hall, Inc. 9 – 59
Wing Component ExampleWing Component 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
© 2008 Prentice Hall, Inc. 9 – 60
Wing Component ExampleWing Component 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
© 2008 Prentice Hall, Inc. 9 – 61
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
Wing Component ExampleWing Component 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
© 2008 Prentice Hall, Inc. 9 – 62
Wing Component ExampleWing Component Example
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
480 available mins per day
40 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
© 2008 Prentice Hall, Inc. 9 – 63
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
Wing Component ExampleWing Component Example
I
GF
H
C
D
B
E
A
10 11
12
5
4
3 7
11
3
Station 1
Station 2
Station 4
Station 5
Station 3
Station 6
Figure 9.14
© 2008 Prentice Hall, Inc. 9 – 64
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
Wing Component ExampleWing Component 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%