1 facility layout: manufacturing and services manufacturing and services chapter 5, part b

1

Facility Layout:Facility Layout:

Manufacturing and ServicesManufacturing and Services

Chapter 5, Part BChapter 5, Part BChapter 5, Part BChapter 5, Part B

2

Facility LayoutFacility LayoutFacility LayoutFacility Layout

Facility layoutFacility layout means planning: means planning: for the location of all machines, utilities, employee for the location of all machines, utilities, employee

workstations, customer service areas, material workstations, customer service areas, material storage areas, aisles, restrooms, lunchrooms, storage areas, aisles, restrooms, lunchrooms, internal walls, offices, and computer roomsinternal walls, offices, and computer rooms

for the flow patterns of materials and people for the flow patterns of materials and people around, into, and within buildingsaround, into, and within buildings

3

Locate All Areas In and Around BuildingsLocate All Areas In and Around BuildingsLocate All Areas In and Around BuildingsLocate All Areas In and Around Buildings

EquipmentEquipment Work stationsWork stations Material storageMaterial storage Rest/break areasRest/break areas UtilitiesUtilities Eating areasEating areas AislesAisles OfficesOffices

4

Characteristics of the Facility Layout DecisionCharacteristics of the Facility Layout DecisionCharacteristics of the Facility Layout DecisionCharacteristics of the Facility Layout Decision

Location of these various areas impacts the flow Location of these various areas impacts the flow through the system.through the system.

The layout can affect productivity and costs The layout can affect productivity and costs generated by the system.generated by the system.

Layout alternatives are limited byLayout alternatives are limited by the amount and type of space required for the the amount and type of space required for the

various areasvarious areas the amount and type of space availablethe amount and type of space available the operations strategythe operations strategy

. . . more. . . more

5

Characteristics of the Facility Layout DecisionCharacteristics of the Facility Layout DecisionCharacteristics of the Facility Layout DecisionCharacteristics of the Facility Layout Decision

Layout decisions tend to be:Layout decisions tend to be: InfrequentInfrequent Expensive to implementExpensive to implement Studied and evaluated extensivelyStudied and evaluated extensively Long-term commitmentsLong-term commitments

6

Manufacturing Facility LayoutsManufacturing Facility LayoutsManufacturing Facility LayoutsManufacturing Facility Layouts

7

Materials HandlingMaterials HandlingMaterials HandlingMaterials Handling

The central focus of most manufacturing layouts is to The central focus of most manufacturing layouts is to minimize the cost of processing, transporting, and minimize the cost of processing, transporting, and storing materials throughout the production system.storing materials throughout the production system.

Materials used in manufacturing include:Materials used in manufacturing include: Raw materialRaw material Purchased componentsPurchased components Work-in-progressWork-in-progress Finished goodsFinished goods Packaging materialPackaging material Maintenance, repair, and operating suppliesMaintenance, repair, and operating supplies

8


A A materials-handling systemmaterials-handling system is the entire network of is the entire network of transportation that:transportation that:

Receives materialReceives material Stores material in inventoriesStores material in inventories Moves material between processing pointsMoves material between processing points Deposits the finished products into vehicles for Deposits the finished products into vehicles for

delivery to customersdelivery to customers

9


Material-Handling PrinciplesMaterial-Handling Principles Move directly (no zigzagging/backtracking)Move directly (no zigzagging/backtracking) Minimize human effort requiredMinimize human effort required Move heavy/bulky items the shortest distancesMove heavy/bulky items the shortest distances Minimize number of times same item is movedMinimize number of times same item is moved MH systems should be flexibleMH systems should be flexible Mobile equipment should carry full loadsMobile equipment should carry full loads

10


Material-Handling EquipmentMaterial-Handling Equipment Automatic transfer devicesAutomatic transfer devices Containers/pallets/hand cartsContainers/pallets/hand carts ConveyorsConveyors CranesCranes ElevatorsElevators PipelinesPipelines TurntablesTurntables AGVSAGVS

11

Basic Layout FormsBasic Layout FormsBasic Layout FormsBasic Layout Forms

ProcessProcess ProductProduct CellularCellular Fixed-PositionFixed-Position HybridHybrid

12

Process (Job Shop) LayoutsProcess (Job Shop) LayoutsProcess (Job Shop) LayoutsProcess (Job Shop) Layouts

Equipment that perform similar processes are Equipment that perform similar processes are grouped togethergrouped together

Used when the operations system must handle a wide Used when the operations system must handle a wide variety of products in relatively small volumes (i.e., variety of products in relatively small volumes (i.e., flexibility is necessary)flexibility is necessary)

13

Characteristics of Process LayoutsCharacteristics of Process LayoutsCharacteristics of Process LayoutsCharacteristics of Process Layouts

General-purpose equipment is usedGeneral-purpose equipment is used Changeover is rapidChangeover is rapid Material flow is intermittentMaterial flow is intermittent Material handling equipment is flexibleMaterial handling equipment is flexible Operators are highly skilledOperators are highly skilled . . . more. . . more

14

Characteristics of Process LayoutsCharacteristics of Process LayoutsCharacteristics of Process LayoutsCharacteristics of Process Layouts

Technical supervision is requiredTechnical supervision is required Planning, scheduling and controlling functions are Planning, scheduling and controlling functions are

challengingchallenging Production time is relatively longProduction time is relatively long In-process inventory is relatively highIn-process inventory is relatively high

15

Product (Assembly Line) LayoutsProduct (Assembly Line) LayoutsProduct (Assembly Line) LayoutsProduct (Assembly Line) Layouts

Operations are arranged in the sequence required to Operations are arranged in the sequence required to make the productmake the product

Used when the operations system must handle a Used when the operations system must handle a narrow variety of products in relatively high volumesnarrow variety of products in relatively high volumes

Operations and personnel are dedicated to producing Operations and personnel are dedicated to producing one or a small number of productsone or a small number of products

16

Characteristics of Product LayoutsCharacteristics of Product LayoutsCharacteristics of Product LayoutsCharacteristics of Product Layouts

Special-purpose equipment are usedSpecial-purpose equipment are used Changeover is expensive and lengthyChangeover is expensive and lengthy Material flow approaches continuousMaterial flow approaches continuous Material handling equipment is fixedMaterial handling equipment is fixed Operators need not be as skilledOperators need not be as skilled . . . more. . . more

17

Characteristics of Product LayoutsCharacteristics of Product LayoutsCharacteristics of Product LayoutsCharacteristics of Product Layouts

Little direct supervision is requiredLittle direct supervision is required Planning, scheduling and controlling functions are Planning, scheduling and controlling functions are

relatively straight-forwardrelatively straight-forward Production time for a unit is relatively shortProduction time for a unit is relatively short In-process inventory is relatively lowIn-process inventory is relatively low

18

Cellular Manufacturing LayoutsCellular Manufacturing LayoutsCellular Manufacturing LayoutsCellular Manufacturing Layouts

Operations required to produce a particular family Operations required to produce a particular family (group) of parts are arranged in the sequence required (group) of parts are arranged in the sequence required to make that familyto make that family

Used when the operations system must handle a Used when the operations system must handle a moderate variety of products in moderate volumesmoderate variety of products in moderate volumes

19

Characteristics of Cellular ManufacturingCharacteristics of Cellular ManufacturingRelative to Process LayoutsRelative to Process Layouts

Characteristics of Cellular ManufacturingCharacteristics of Cellular ManufacturingRelative to Process LayoutsRelative to Process Layouts

Equipment can be less general-purposeEquipment can be less general-purpose Material handling costs are reducedMaterial handling costs are reduced Training periods for operators are shortenedTraining periods for operators are shortened In-process inventory is lowerIn-process inventory is lower Parts can be made faster and shipped more quicklyParts can be made faster and shipped more quickly

20

Characteristics of Cellular ManufacturingCharacteristics of Cellular ManufacturingRelative to Product LayoutsRelative to Product Layouts

Characteristics of Cellular ManufacturingCharacteristics of Cellular ManufacturingRelative to Product LayoutsRelative to Product Layouts

Equipment can be less special-purposeEquipment can be less special-purpose Changeovers are simplifiedChangeovers are simplified Production is easier to automateProduction is easier to automate

21

Fixed-Position LayoutsFixed-Position LayoutsFixed-Position LayoutsFixed-Position Layouts

Product remains in a fixed position, and the Product remains in a fixed position, and the personnel, material and equipment come to itpersonnel, material and equipment come to it

Used when the product is very bulky, large, heavy or Used when the product is very bulky, large, heavy or fragile fragile

22

Hybrid LayoutsHybrid LayoutsHybrid LayoutsHybrid Layouts

Actually, most manufacturing facilities use a Actually, most manufacturing facilities use a combination of layout types.combination of layout types.

An example of a hybrid layout is where departments An example of a hybrid layout is where departments are arranged according to the types of processes but are arranged according to the types of processes but the products flow through on a product layout.the products flow through on a product layout.

23

New Trends in Manufacturing LayoutsNew Trends in Manufacturing LayoutsNew Trends in Manufacturing LayoutsNew Trends in Manufacturing Layouts

Designed for qualityDesigned for quality Designed for flexibility - to quickly shift to different Designed for flexibility - to quickly shift to different

product models or to different production ratesproduct models or to different production rates Cellular layout within larger process layoutsCellular layout within larger process layouts Automated material handlingAutomated material handling U-shaped production linesU-shaped production lines . . . more. . . more

24

New Trends in Manufacturing LayoutsNew Trends in Manufacturing LayoutsNew Trends in Manufacturing LayoutsNew Trends in Manufacturing Layouts

More open work areas with fewer walls, partitions, or More open work areas with fewer walls, partitions, or other obstaclesother obstacles

Smaller and more compact factory layoutsSmaller and more compact factory layouts Less space provided for storage of inventories Less space provided for storage of inventories

throughout the layoutthroughout the layout

25

Planning Manufacturing Facility LayoutsPlanning Manufacturing Facility LayoutsPlanning Manufacturing Facility LayoutsPlanning Manufacturing Facility Layouts

Two Categories of Software ToolsTwo Categories of Software Tools Computer aided design (CAD)Computer aided design (CAD)

Allows 3-D, full-color views of facility designAllows 3-D, full-color views of facility design Allows virtual walk-throughsAllows virtual walk-throughs Ex. – ArchiCAD, AutoSketch, AutoCADEx. – ArchiCAD, AutoSketch, AutoCAD

Computer simulationComputer simulation Can simulate proposed system layout in operation Can simulate proposed system layout in operation

and measure its performanceand measure its performance Ex. – ProModel, VisFactory, SIMPROCESSEx. – ProModel, VisFactory, SIMPROCESS

26

Process and Warehouse LayoutsProcess and Warehouse Layouts Product LayoutsProduct Layouts Cellular Manufacturing LayoutsCellular Manufacturing Layouts


27


Process LayoutsProcess Layouts Primary focus is on the efficient flow of materialsPrimary focus is on the efficient flow of materials The wide variety of potential product routings The wide variety of potential product routings

through the facility can be evaluated using through the facility can be evaluated using computer simulationcomputer simulation

Warehouse LayoutsWarehouse Layouts Primary focus is the fast storage and retrieval of Primary focus is the fast storage and retrieval of

inventory itemsinventory items Decisions about aisle size/placement and location Decisions about aisle size/placement and location

of each inventory item can be evaluated using of each inventory item can be evaluated using computer simulationcomputer simulation

28


Product LayoutsProduct Layouts Primary focus is on the analysis of production linesPrimary focus is on the analysis of production lines The goal of the production line analysis is to:The goal of the production line analysis is to:

Determine how many workstations to haveDetermine how many workstations to have Determine which tasks to assign to which Determine which tasks to assign to which

workstationworkstation Minimize the number of workers & machines usedMinimize the number of workers & machines used Provide the required amount of capacityProvide the required amount of capacity

Line balancingLine balancing is a key part of the analysis is a key part of the analysis

29

Planning Product LayoutsPlanning Product LayoutsPlanning Product LayoutsPlanning Product Layouts

Line Balancing ProcedureLine Balancing Procedure

1. Determine the tasks involved in completing 1 unit1. Determine the tasks involved in completing 1 unit

2. Determine the order in which tasks must be done2. Determine the order in which tasks must be done

3. Draw a precedence diagram3. Draw a precedence diagram

4. Estimate task times4. Estimate task times

5. Calculate the cycle time5. Calculate the cycle time

6. Calculate the minimum number of workstations6. Calculate the minimum number of workstations

7. Use a heuristic to assign tasks to workstations7. Use a heuristic to assign tasks to workstations

30


Line Balancing HeuristicsLine Balancing Heuristics Heuristic methodsHeuristic methods, based on simple rules, have been , based on simple rules, have been

developed to provide good (not optimal) solutions to developed to provide good (not optimal) solutions to line balancing problemsline balancing problems

Heuristic methods include:Heuristic methods include: Incremental utilization (IU) methodIncremental utilization (IU) method Longest-task-time (LTT) methodLongest-task-time (LTT) method … … and many othersand many others

31


Incremental Utilization MethodIncremental Utilization Method Add tasks to a workstation in order of task Add tasks to a workstation in order of task

precedence one at a time until utilization is 100% or precedence one at a time until utilization is 100% or is observed to fallis observed to fall

Then the above procedure is repeated at the next Then the above procedure is repeated at the next workstation for the remaining tasksworkstation for the remaining tasks

Pro – Appropriate when one or more task times is Pro – Appropriate when one or more task times is equal to or greater than the cycle timeequal to or greater than the cycle time

Con – Might create the need for extra equipmentCon – Might create the need for extra equipment

32


Longest-Task-Time MethodLongest-Task-Time Method Adds tasks to a workstation one at a time in the order Adds tasks to a workstation one at a time in the order

of task precedence.of task precedence. If two or more tasks tie for order of precedence, the If two or more tasks tie for order of precedence, the

one with the longest task time is addedone with the longest task time is added Conditions for its use:Conditions for its use:

No task time can be greater than the cycle timeNo task time can be greater than the cycle time There can be no duplicate workstationsThere can be no duplicate workstations

33

Example: Armstrong PumpsExample: Armstrong PumpsExample: Armstrong PumpsExample: Armstrong Pumps

Line BalancingLine Balancing

Armstrong produces bicycle tire pumps on a Armstrong produces bicycle tire pumps on a production line. The time to perform the 6 tasks in production line. The time to perform the 6 tasks in producing a pump and their immediate predecessor producing a pump and their immediate predecessor tasks are shown on the next slide.tasks are shown on the next slide.

Ten pumps per hour must be produced and 45 Ten pumps per hour must be produced and 45 minutes per hour are productive.minutes per hour are productive.

Use the incremental utilization heuristic to Use the incremental utilization heuristic to combine the tasks into workstations in order to combine the tasks into workstations in order to minimize idle time.minimize idle time.

34


Line BalancingLine Balancing Tasks thatTasks that Time to Time toImmediatelyImmediately Perform Perform

TaskTask PrecedePrecede Task (min.)Task (min.) AA ---- 5.4 5.4

BB AA 3.2 3.2 CC ---- 1.5 1.5 DD B,C B,C 2.8 2.8 EE DD 17.1 17.1 FF EE 12.812.8

Total = 42.8Total = 42.8

35


Line Balancing – Network (Precedence) DiagramLine Balancing – Network (Precedence) Diagram

AAAA

CCCC

BBBB EEEEDDDD FFFF

36


Line Balancing – Cycle TimeLine Balancing – Cycle Time

= 45/10 = 4.5 minutes per pump= 45/10 = 4.5 minutes per pump

Productive Time per HourCycle Time =

Demand per Hour

Productive Time per HourCycle Time =

Demand per Hour

37


Line Balancing – Minimum Number of WorkstationsLine Balancing – Minimum Number of Workstations

MinimumMinimum Number ofNumber ofWorkstationsWorkstations

= [(42.8)(10)]/45 = 9.51 workstations= [(42.8)(10)]/45 = 9.51 workstations

(Total Task Time)(Demand per Hour)=

Productive Time per Hour

(Total Task Time)(Demand per Hour)=

Productive Time per Hour

38


Line Balancing – Incremental Utilization HeuristicLine Balancing – Incremental Utilization Heuristic

WS TasksWS Tasks Mins./pump Mins./pump #WS’s Incr.Util. #WS’s Incr.Util. 11 AA 5.4 5.4 5.4/4.5=1.2= 2 60.0% 5.4/4.5=1.2= 2 60.0% 11 A,BA,B 5.4 + 3.2 5.4 + 3.2 8.6/4.5=1.9= 2 95.0% 8.6/4.5=1.9= 2 95.0% 11 A,B,CA,B,C 8.6 + 1.5 8.6 + 1.5 10.1/4.5=2.2= 3 49.8% 10.1/4.5=2.2= 3 49.8% 22 CC 1.5 1.5 1.5/4.5=.33= 1 33.3% 1.5/4.5=.33= 1 33.3% 22 C,DC,D 1.5 + 2.8 1.5 + 2.8 4.3/4.5=.96= 1 95.6% 4.3/4.5=.96= 1 95.6% 22 C,D,EC,D,E 4.3 + 17.1 21.4/4.5=4.8= 5 95.1% 4.3 + 17.1 21.4/4.5=4.8= 5 95.1% 33 EE 17.1 17.1 17.1/4.5=3.8= 4 95.0% 17.1/4.5=3.8= 4 95.0% 33 E,FE,F 17.1 + 12.8 29.9/4.5=6.6= 7 94.9% 17.1 + 12.8 29.9/4.5=6.6= 7 94.9% 44 FF 12.8 12.8 12.8/4.5=2.8= 3 94.8% 12.8/4.5=2.8= 3 94.8%

39


Line Balancing – Utilization of Production LineLine Balancing – Utilization of Production Line

= 9.51/10 = .951 = 95.1% = 9.51/10 = .951 = 95.1%

Minimum Number of WorkstationsUtilization =

Actual Number of WorkstationsMinimum Number of Workstations

Utilization = Actual Number of Workstations

40


Rebalancing a Production LineRebalancing a Production Line Changes that can lead to production lines being out of Changes that can lead to production lines being out of

balance or having insufficient/excess capacity are:balance or having insufficient/excess capacity are: Changes in demandChanges in demand Machine modificationsMachine modifications Variations in employee learning and trainingVariations in employee learning and training

41

Planning Cellular Manufacturing LayoutsPlanning Cellular Manufacturing LayoutsPlanning Cellular Manufacturing LayoutsPlanning Cellular Manufacturing Layouts

Cell Formation DecisionCell Formation Decision Which machines are assigned to manufacturing Which machines are assigned to manufacturing

cellscells Which parts will be produced in each cellWhich parts will be produced in each cell

42


Fundamental Requirements for Parts to be Made in Fundamental Requirements for Parts to be Made in CellsCells Demand for the parts must be high enough and Demand for the parts must be high enough and

stable enough that moderate batch sizes of the stable enough that moderate batch sizes of the parts can be produced periodically.parts can be produced periodically.

Parts must be capable of being grouped into parts Parts must be capable of being grouped into parts families.families.

43


More-Complex Issues to be ResolvedMore-Complex Issues to be Resolved If all the parts cannot be cleanly divided between If all the parts cannot be cleanly divided between

cells, how will we decide which are to be the cells, how will we decide which are to be the exceptional parts?exceptional parts?

If inadequate capacity is available to produce all the If inadequate capacity is available to produce all the parts in cells, which parts should be made outside the parts in cells, which parts should be made outside the cells?cells?

44


Cell Formation ProcedureCell Formation Procedure1.1. Form the Parts-Machines Matrix. Form the Parts-Machines Matrix.2.2. Rearrange the Rows. Rearrange the Rows.

Place the machines that produce the same parts in Place the machines that produce the same parts in adjacent rows.adjacent rows.

3.3. Rearrange the Columns. Rearrange the Columns. Place the parts requiring the same machines in Place the parts requiring the same machines in

adjacent columns.adjacent columns.4.4. Use the rearranged parts-machines matrix to identify Use the rearranged parts-machines matrix to identify

cells, the machines for that cell and the parts that will cells, the machines for that cell and the parts that will be produced in that cell.be produced in that cell.

1 facility layout: manufacturing and services manufacturing and services chapter 5, part b

Documents