Mark M. Davis
Janelle Heineke
OPERATIONS MANAGEMENT
INTEGRATING MANUFACTURING AND SERVICES
FIFTH EDITION
PowerPoint Presentation by
Charlie Cook, The University of West Alabama
Copyright ©2005, The McGraw-Hill Companies, Inc.
CHAPTER
12
Facility Layouts
PowerPoint Presentation by Charlie Cook
The University of West Alabama
Copyright © 2005 The McGraw-Hill Companies. All rights reserved.
CHAPTER OBJECTIVES
• Introduce the various facility layouts that are used in
manufacturing and service operations.
• Present a methodology for designing a process-oriented
layout.
• Introduce the concept of takt time and its relationship to
the output capacity of a product-oriented layout.
• Identify the steps and elements involved in balancing an
assembly line.
• Discuss the current trends in facility layouts given today’s
shorter product life cycles and the customer’s increasing
desire for customized products.
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McGraw-Hill/Irwin 12–3
Managerial Issues
• Recognizing that many factors must be considered in
choosing how to layout a facility.
• Understanding the significant impact that choosing a
particular type of layout has on the firm’s ability to
compete in the market and its long-term success.
• Developing estimates of the investment costs of time and
money associated with installing a particular layout.
• Attaining the goal of a smooth flow of material through the
process through the choice of a layout that is both
efficient and effective.
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McGraw-Hill/Irwin 12–4
Types of Manufacturing Layouts
Layout Type
Process
Similar operations are performed in a
common or functional area, regardless of
the product in which the parts are used.
Product
(Flow-shop layout)
Equipment/operations are located
according to the progressive steps required
to make the product.
Fixed-Position
The product, because of its size and/or
weight, remains in one location and
processes are brought to it.
Group Technology
(GT) or Cellular
Groups of dissimilar machines are brought
together in a work cell to perform tasks on a
family of products that share common
interests.
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Characteristics of a Good Layout
Exhibit 12.1
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Process Layout
• Developing a manufacturing or services process
layout
– Arrange departments consisting of similar or identical
processes in a way that optimizes their relative
placement,
– Optimal placement involves placing departments with
large amounts of interdepartmental traffic adjacent to
one another to minimize material handling costs.
– For service process, the main objective is to minimize
customer and worker travel time through the process.
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Interdepartmental Flow
Exhibit 12.2
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Building Dimensions and Departments
Exhibit 12.3
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Interdepartmental Flow Graph with
Number of Annual Movements
Exhibit 12.4
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Cost Matrix—First Solution
Exhibit 12.5
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Revised Interdepartmental Flowchart*
*Only interdepartmental flow with effect on cost is depicted.
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Exhibit 12.6
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Cost Matrix—Second Solution
Exhibit 12.7
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Revised Building Layout
Exhibit 12.8
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Product Layout
• Assembly Lines
–A progressive paced assembly linked by some sort of
material handling device.
• Assembly Line Type Differences
–Material handling devices
–Line configuration
–Pacing (machine or human)
–Product mix
–Workstation characteristic
–Length of line
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Illustrating Cycle Time and Throughput Time
on an Assembly Line
Exhibit 12.9
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Product Layout: Key Terms
• Product Interval Time
–The time between products being completed
(processed through) at a single station (process step).
Also, cycle time or takt time.
• Product Duration (Throughput) Time.
–The overall time required to entirely complete an
individual product.
• Assembly Line Balancing
–Assignment of tasks to workstations within a given
cycle time and with minimum idle worker time.
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Assembly Line Balancing Steps
1. Specify the sequential relationships among tasks using a
precedence diagram.
2. Determine the required takt (T) time.
3. Determine the theoretical minimum number of
workstations (Nt) required to satisfy the takt time
constraint.
4. Select a primary rule by which tasks are to be assigned
to workstations and a secondary rule to break ties.
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Assembly Line Balancing Steps (cont’d)
5. Assign tasks, one at a time, to the first workstation until
the sum of the task times is equal to the takt time.
Continue assigning tasks to other workstations until all
tasks are assigned.
6. Evaluate the efficiency of the resulting assembly line.
7. If efficiency is unsatisfactory, rebalance the line using a
different decision rule in step 4.
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Takt Time and Throughput Time
on an Assembly Line
Matching task time to takt time:
1.
2.
3.
4.
5.
6.
Split the task
Duplicate the station
Share the task
Use a more skilled worker
Work overtime
Redesign the product
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Assembly Line Balancing Formulas
Production time per day
Takt time (T) =
Output per day (in units)
Sum of task times (S)
Number of workstations =
Takt time (T)
Efficiency =
Sum of task times (S)
Actual number of workstations (Na)  Takt time (T)
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Assembly Steps and Times for Model J Wagon
Exhibit 12.10
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Precedence Graph for Model J Wagon
Exhibit 12.11
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Balance Made According to
Largest Number of Following Tasks Rule
*Denotes task arbitrarily selected where there is a tie between longest operation times.
Exhibit 12.12A
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Precedence
Graph for Model
J Wagon
Efficiency Calculation
Exhibit 12.12 (cont’d)
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Efficiency Calculation
S
Efficiency =
NT
195
Efficiency =
= 0.77 , or 77 %
550.4
Exhibit 12.12 (cont’d)
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Flexible
Line Layouts
Exhibit 12.13
Source: Robert W. Hall, Attaining Manufacturing Excellence
(Homewood, IL: Dow Jones–Irwin, 1987), p. 125.
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Group Technology (Cellular) Layout
• Benefits
–Better human relations in small work teams.
–Improved operator expertise from the limited number
of parts and quick production cycle.
–Less work-in-process inventory and material handling
due to reduced number of production stages.
–Faster production setup from faster tooling changes.
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Group Technology (GT) Layout
• Developing a GT Layout
–Grouping parts into families that follow a common
sequence of steps.
–Identifying dominant flow patterns of parts-families for
location of processes.
–Physically grouping machines and processes into cells.
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Facilities Layout for Services
• Goals of Service Facility Layouts
–Minimize travel time for workers and customers
–Maximize revenues from customers
• Types of Service Layouts
–Process layout—emergency rooms
–Product layout—cafeteria line
–Fixed-position layout—automobile repair shop
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Facilities Layout for Services (cont’d)
• Servicescape
–The aspects of the physical surroundings in a service
operation that can affect a customer’s perception of the
service received.
–Ambient conditions
• Noise, lighting, and temperature
–Spatial layout and functionality
• Minimizing employee travel time and maximizing revenue
opportunities from customers
–Signs, symbols, and artifacts
• Objects that create positive images of the firm
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