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Chapter 5, Part B. Facility Layout: Manufacturing and Services. Overview. Facility Layout Manufacturing Facility Layouts Analyzing Manufacturing Facility Layouts Service Facility Layouts Wrap-Up: What World-Class Companies Do. Facility Layout. Facility layout means planning: - PowerPoint PPT Presentation
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1 1 2002 South-Western/Thomson Learning 2002 South-Western/Thomson Learning TMTM
Slides preparedSlides preparedby John Loucksby John Loucks
2
Facility Layout: Manufacturing and Services
Chapter 5, Part B
3
Overview
Facility Layout Manufacturing Facility Layouts Analyzing Manufacturing Facility Layouts Service Facility Layouts Wrap-Up: What World-Class Companies Do
4
Facility Layout
Facility layout means planning: for the location of all machines, utilities, employee
workstations, customer service areas, material storage areas, aisles, restrooms, lunchrooms, internal walls, offices, and computer rooms
for the flow patterns of materials and people around, into, and within buildings
5
Locate All Areas In and Around Buildings
Equipment Work stations Material storage Rest/break areas Utilities Eating areas Aisles Offices
6
Characteristics of the Facility Layout Decision
Location of these various areas impacts the flow through the system.
The layout can affect productivity and costs generated by the system.
Layout alternatives are limited by the amount and type of space required for the
various areas the amount and type of space available the operations strategy
. . . more
7
Characteristics of the Facility Layout Decision
Layout decisions tend to be: Infrequent Expensive to implement Studied and evaluated extensively Long-term commitments
8
Manufacturing Facility Layouts
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Materials Handling
The central focus of most manufacturing layouts is to minimize the cost of processing, transporting, and storing materials throughout the production system.
Materials used in manufacturing include: Raw material Purchased components Work-in-progress Finished goods Packaging material Maintenance, repair, and operating supplies
10
Materials Handling
A materials-handling system is the entire network of transportation that:
Receives material Stores material in inventories Moves material between processing points Deposits the finished products into vehicles for
delivery to customers
11
Materials Handling
Material-Handling Principles Move directly (no zigzagging/backtracking) Minimize human effort required Move heavy/bulky items the shortest distances Minimize number of times same item is moved MH systems should be flexible Mobile equipment should carry full loads
12
Materials Handling
Material-Handling Equipment Automatic transfer devices Containers/pallets/hand carts Conveyors Cranes Elevators Pipelines Turntables AGVS
13
Basic Layout Forms
Process Product Cellular Fixed-Position Hybrid
14
Process (Job Shop) Layouts
Equipment that perform similar processes are grouped together
Used when the operations system must handle a wide variety of products in relatively small volumes (i.e., flexibility is necessary)
15
Characteristics of Process Layouts
General-purpose equipment is used Changeover is rapid Material flow is intermittent Material handling equipment is flexible Operators are highly skilled . . . more
16
Characteristics of Process Layouts
Technical supervision is required Planning, scheduling and controlling functions are
challenging Production time is relatively long In-process inventory is relatively high
17
Product (Assembly Line) Layouts
Operations are arranged in the sequence required to make the product
Used when the operations system must handle a narrow variety of products in relatively high volumes
Operations and personnel are dedicated to producing one or a small number of products
18
Characteristics of Product Layouts
Special-purpose equipment are used Changeover is expensive and lengthy Material flow approaches continuous Material handling equipment is fixed Operators need not be as skilled . . . more
19
Characteristics of Product Layouts
Little direct supervision is required Planning, scheduling and controlling functions are
relatively straight-forward Production time for a unit is relatively short In-process inventory is relatively low
20
Cellular Manufacturing Layouts
Operations required to produce a particular family (group) of parts are arranged in the sequence required to make that family
Used when the operations system must handle a moderate variety of products in moderate volumes
21
Characteristics of Cellular ManufacturingRelative to Process Layouts
Equipment can be less general-purpose Material handling costs are reduced Training periods for operators are shortened In-process inventory is lower Parts can be made faster and shipped more quickly
22
Characteristics of Cellular ManufacturingRelative to Product Layouts
Equipment can be less special-purpose Changeovers are simplified Production is easier to automate
23
Fixed-Position Layouts
Product remains in a fixed position, and the personnel, material and equipment come to it
Used when the product is very bulky, large, heavy or fragile
24
Hybrid Layouts
Actually, most manufacturing facilities use a combination of layout types.
An example of a hybrid layout is where departments are arranged according to the types of processes but the products flow through on a product layout.
25
New Trends in Manufacturing Layouts
Designed for quality Designed for flexibility - to quickly shift to different
product models or to different production rates Cellular layout within larger process layouts Automated material handling U-shaped production lines . . . more
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New Trends in Manufacturing Layouts
More open work areas with fewer walls, partitions, or other obstacles
Smaller and more compact factory layouts Less space provided for storage of inventories
throughout the layout
27
Planning Manufacturing Facility Layouts
Two Categories of Software Tools Computer aided design (CAD)
Allows 3-D, full-color views of facility design Allows virtual walk-throughs Ex. – ArchiCAD, AutoSketch, AutoCAD
Computer simulation Can simulate proposed system layout in operation
and measure its performance Ex. – ProModel, VisFactory, SIMPROCESS
28
Process and Warehouse Layouts Product Layouts Cellular Manufacturing Layouts
Planning Manufacturing Facility Layouts
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Planning Manufacturing Facility Layouts
Process Layouts Primary focus is on the efficient flow of materials The wide variety of potential product routings
through the facility can be evaluated using computer simulation
Warehouse Layouts Primary focus is the fast storage and retrieval of
inventory items Decisions about aisle size/placement and location
of each inventory item can be evaluated using computer simulation
30
Planning Manufacturing Facility Layouts
Product Layouts Primary focus is on the analysis of production lines The goal of the production line analysis is to:
Determine how many workstations to have Determine which tasks to assign to which
workstation Minimize the number of workers & machines used Provide the required amount of capacity
Line balancing is a key part of the analysis
31
Planning Product Layouts
Line Balancing Procedure1. Determine the tasks involved in completing 1 unit2. Determine the order in which tasks must be done3. Draw a precedence diagram4. Estimate task times5. Calculate the cycle time6. Calculate the minimum number of workstations7. Use a heuristic to assign tasks to workstations
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Planning Product Layouts
Line Balancing Heuristics Heuristic methods, based on simple rules, have been
developed to provide good (not optimal) solutions to line balancing problems
Heuristic methods include: Incremental utilization (IU) method Longest-task-time (LTT) method … and many others
33
Planning Product Layouts
Incremental Utilization Method Add tasks to a workstation in order of task
precedence one at a time until utilization is 100% or is observed to fall
Then the above procedure is repeated at the next workstation for the remaining tasks
Pro – Appropriate when one or more task times is equal to or greater than the cycle time
Con – Might create the need for extra equipment
34
Planning Product Layouts
Longest-Task-Time Method Adds tasks to a workstation one at a time in the order
of task precedence. If two or more tasks tie for order of precedence, the
one with the longest task time is added Conditions for its use:
No task time can be greater than the cycle time There can be no duplicate workstations
35
Example: Armstrong Pumps
Line BalancingArmstrong produces bicycle tire pumps on a
production line. The time to perform the 6 tasks in producing a pump and their immediate predecessor tasks are shown on the next slide.
Ten pumps per hour must be produced and 45 minutes per hour are productive.
Use the incremental utilization heuristic to combine the tasks into workstations in order to minimize idle time.
36
Example: Armstrong Pumps
Line Balancing Tasks that Time toImmediately Perform
Task Precede Task (min.) A -- 5.4
B A 3.2 C -- 1.5 D B,C 2.8 E D 17.1 F E 12.8
Total = 42.8
37
Example: Armstrong Pumps
Line Balancing – Network (Precedence) Diagram
A
C
B ED F
38
Example: Armstrong Pumps
Line Balancing – Cycle Time
= 45/10 = 4.5 minutes per pump
Productive Time per HourCycle Time = Demand per Hour
39
Example: Armstrong Pumps
Line Balancing – Minimum Number of Workstations
Minimum Number ofWorkstations
= [(42.8)(10)]/45 = 9.51 workstations
(Total Task Time)(Demand per Hour)= Productive Time per Hour
40
Example: Armstrong Pumps
Line Balancing – Incremental Utilization HeuristicWS Tasks Mins./pump #WS’s
Incr.Util. 1 A 5.4 5.4/4.5=1.2= 2
60.0% 1 A,B 5.4 + 3.2 8.6/4.5=1.9= 2
95.0% 1 A,B,C 8.6 + 1.5 10.1/4.5=2.2= 3
49.8% 2 C 1.5 1.5/4.5=.33= 1
33.3% 2 C,D 1.5 + 2.8 4.3/4.5=.96= 1
95.6% 2 C,D,E 4.3 + 17.1 21.4/4.5=4.8= 5
95.1% 3 E 17.1 17.1/4.5=3.8= 4
95.0% 3 E,F 17.1 + 12.8 29.9/4.5=6.6= 7
94.9% 4 F 12.8 12.8/4.5=2.8= 3
94.8%
41
Example: Armstrong Pumps
Line Balancing – Utilization of Production Line
= 9.51/10 = .951 = 95.1%
Minimum Number of WorkstationsUtilization = Actual Number of Workstations
42
Planning Product Layouts
Rebalancing a Production Line Changes that can lead to production lines being out of
balance or having insufficient/excess capacity are: Changes in demand Machine modifications Variations in employee learning and training
43
Planning Cellular Manufacturing Layouts
Cell Formation Decision Which machines are assigned to manufacturing
cells Which parts will be produced in each cell
44
Planning Cellular Manufacturing Layouts
Fundamental Requirements for Parts to be Made in Cells
Demand for the parts must be high enough and stable enough that moderate batch sizes of the parts can be produced periodically.
Parts must be capable of being grouped into parts families.
45
Planning Cellular Manufacturing Layouts
More-Complex Issues to be Resolved If all the parts cannot be cleanly divided between
cells, how will we decide which are to be the exceptional parts?
If inadequate capacity is available to produce all the parts in cells, which parts should be made outside the cells?
46
Planning Cellular Manufacturing Layouts
Cell Formation Procedure1. Form the Parts-Machines Matrix.2. Rearrange the Rows.
Place the machines that produce the same parts in adjacent rows.
3. Rearrange the Columns. Place the parts requiring the same machines in
adjacent columns.4. Use the rearranged parts-machines matrix to identify
cells, the machines for that cell and the parts that will be produced in that cell.
47
Example: Maxx Superchargers
Cell FormulationMaxx produces superchargers for high
performance cars and trucks. Maxx has implemented a group technology program in its shop and now must formulate the manufacturing cells. Maxx has identified six parts that meet the requirements for CM.
The parts-machines matrix on the next slide identifies the 6 parts and 5 machines on which the parts are presently produced.
48
Example: Maxx Superchargers
Cell Formulation – Original Matrix
1 2 3 4 5 6X X X
X X X XX X
X XX X X
ABCDE
Parts
Machines
49
Example: Maxx Superchargers
Cell Formulation – Rows Rearranged
1 2 3 4 5 6X X XX X X
X XX XX X X X
AEDCB
Parts
Machines
50
Example: Maxx Superchargers
Cell Formulation – Columns Rearranged
3 5 6* 1 2 4X X XX X X
X XX X
X X X X
AEDCB
Parts
Machines
* exceptional part
51
Example: Maxx Superchargers
Cell Formulation – Summary 2 manufacturing cells (MC1, MC2) will be used. Parts 3 and 5 will be produced in MC1 on
machines A and E. Parts 1, 2 and 4 will be produced in MC2 on
machines B, C and D. Part 6 is an exceptional part that cannot be
produced within a single cell.
52
Service Facility Layouts
53
Characteristics of Services
There may be a diversity of services provided There are three dimensions to the type of service:
Standard or custom design Amount of customer contact Mix of physical goods and intangible services
There are three types of service operations: Quasi manufacturing Customer-as-participant Customer-as-product
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Characteristics of Service Facility Layouts
The encounter between the customer and the service must be provided for.
The degree to which customer-related features must be provided varies with the amount of customer involvement and customer contact.
55
Planning Service Facility Layouts
Quasi-Manufacturing Services Several topics previously discussed under
Manufacturing Layouts are relevant here: Principles of material handling CAD and simulation software Line balancing
56
Planning Service Facility Layouts
Customer-as-Participant & Customer-as-Product An important element is providing for customer
waiting lines Amount of space needed for service counters
and waiting customers Placement of waiting lines in overall layout
57
Planning Service Facility Layouts
For many service operations, layouts are like process layouts in manufacturing
The departments of hospitals are grouped and located according to their processes
In some cases, closeness ratings are used to reflect the desirability of having one department near another
58
Using Closeness Ratings to Develop Service Facility Layouts Start Let m = 1 and n = 6.
Identify dept. pairs with CR of m.
Develop layout with dept. pairs iden- tified in Step 2 adjacent to one another.
Identify dept. pairs with CR of n.
Fit the dept. pairs identified in Step 4into the trial layout from Step 3.
Step 1
Step 2
Step 3
Step 4
Step 5
Examine the trial layout from Step 5.If any CRs of dept. pairs are violated,rearrange depts. to comply with CRs.
Step 6
Doesm = 3 and n = 4
?
Stop
Let m = m + 1 and n = n - 1.
No
Yes
59
Using Closeness Ratings to Develop Service Facility Layouts
Typical Closeness Ratings
Closeness Meaning Rating of Rating
1 Necessary 2 Very Important 3 Important 4 Slightly Important 5 Unimportant 6 Undesirable
60
Example: AG Advertising
Using Closeness RatingsAG Advertising is moving into a new office
suite having seven large, roughly equal size rooms, one for each department of the firm. Lisa, the manager, must now assign each department to a room. She has developed a grid of closeness ratings (on the next slide) for the 21 unique pairs of departments.
61
Example: AG Advertising
5
6
4
4
2
33
5
41
26
24
33
165
12
Closeness Ratings Grid
Dept. A Dept. B Dept. C Dept. D Dept. E Dept. F Dept. G
62
Example: AG Advertising
Unassigned Rooms of Office Suite
63
Layout Satisfying All Pairings ofDepartments with 1 Closeness Ratings
CR = 1 B – D B – F C – G
Example: AG Advertising
B D
F C G
64
Trying to satisfying all pairings of departments with6 closeness ratings, we see that Dept. C needs to bemoved.
CR = 1 CR = 6 B – D A – D B – F B – C C – G
Example: AG Advertising
B D
F G C
65
Example: AG Advertising
Layout Satisfying All Pairings of Departments with 6 Closeness Ratings (note that we swapped Dept. D and Dept. F)
CR = 1 CR = 6 B – D A – D B – F B – C C – G
B F A
D E G C
66
Wrap-Up: World-Class Practice
Strive for flexibility in layouts Multi-job training of workers Sophisticated preventive-maintenance programs Flexible machines Empowered workers trained in problem solving Layouts small and compact
Services follow the above practices plus incorporate customer needs in design
67
End of Chapter 5, Part B