Chapter 10 – Facility Layout
Operations Management
by
R. Dan Reid & Nada R. Sanders
2nd Edition © Wiley 2005
PowerPoint Presentation by R.B. Clough - UNH
Learning Objectives
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Define layout planning and its importance
Identify and describe different types of layouts
Compare process layouts & product layouts
Describe the steps involved in designing both
process and product layouts
Explain the advantages of hybrid layouts
Define the meaning of group technology & its
importance to cellular layouts
What Is Layout Planning
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Layout planning is determining the best
physical arrangement of resources
within a facility
Two broad categories of operations:
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Intermittent processing systems
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Continuous processing systems
Types of Layouts
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Process layouts:
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Product layouts:
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Designed to produce a specific product efficiently
Hybrid layouts:
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Group similar resources together
Combine aspects of both process and product layouts
Fixed-Position layouts:
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Product is two large to move; e.g. a building
Process Layouts
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General purpose & flexible resources
Lower capital intensity & automation
Higher labor intensity
Resources have greater flexibility
Processing rates are slower
Material handling costs are higher
Scheduling resources & work flow is more
complex
Space requirements are higher
Product Layouts
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Specialized equipment
High capital intensity & wide use of
automation
Processing rates are faster
Material handling costs are lower
Less space required for inventories
Less volume or design flexibility
Hybrid Layouts
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Combine elements of both product &
process layouts
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Maintain some of the efficiencies of product
layouts
Maintain some of the flexibility of process
layouts
Examples:
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Group technology & manufacturing cells
Grocery stores
Comparison of Product vs. Product Layouts
Process Layouts
Product Layouts
Products:
large #, different
small # efficiently
Resources:
general purpose
specialized
Facilities:
more labor intensive
more capital intensive
Flexibility:
greater relative to market
lower relative to market
Processing
Rates:
slower
faster
Handling costs: high
low
Space requirements: higher
lower
Designing Process Layouts
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Step 1: Gather information:
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Step 2: Develop alternative block plans:
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Space needed, space available, importance of
proximity between various units
Using trial-and-error or decision support tools
Step 3: Develop a detailed layout
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Consider exact sizes and shapes of departments
and work centers including aisles and stairways
Tools like drawings, 3-D models, and CAD
software are available to facilitate this process
Process Layout Steps
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Step 1: Gather information like space needed, from-to matrix,
and REL Chart for Recovery First Sports Medicine Clinic (total
space 3750 sq. ft.)
A
Radiology
B
Laboratory
400 sq. ft.
300 sq. ft.
C
Lobby &
Waiting
300 sq. ft.
D
Examining
Rooms
800 sq. ft.
E
Surgery &
Recovery
900 sq. ft.
F
Physical
Therapy
1050 sq. ft.
Step 1: Gather Information (continued)
Step 2: Develop a New Block Layout
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Use trial and error with
from-to and REL Charts as a guide
Use computer software like ALDEP
or CRAFT
Warehouse Layouts
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Warehouse Layout Considerations:
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Primary decision is where to locate each department
relative to the dock
Departments can be organized to minimize “ld”
totals
Departments of unequal size require modification of
the typical ld calculations to include a calculation
of the “ratio of trips to area needed”
The usage of “Crossdocking” (see Ch.4) modifies
the traditional warehouse layouts; more docks, less
storage space, and less order picking
Office Layouts
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Office Layout Considerations:
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Almost half of US workforce works in an office
environment
Human interaction and communication are the primary
factors in designing office layouts
Layouts need to account for physical environment and
psychological needs of the organization
One key layout trade-off is between proximity and
privacy
Open concept offices promote understanding & trust
Flexible layouts incorporating “office landscaping” help
to solve the privacy issue in open office environments
Designing Product Layouts
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Step
Step
Step
Step
1:
2:
3:
4:
Identify tasks & immediate predecessors
Determine the desired output rate
Calculate the cycle time
Compute the theoretical minimum number
of workstations
Step 5: Assign tasks to workstations (balance the
line)
Step 6: Compute efficiency, idle time & balance
delay
Step 1: Identify Tasks &
Immediate Predecessors
Example 10.4 Vicki's Pizzeria and the Precedence Diagram
Immediate
Task Time
Work Element Task Description
Predecessor
(seconds
A
B
C
D
E
F
G
H
I
Roll dough
Place on cardboard backing
Sprinkle cheese
Spread Sauce
Add pepperoni
Add sausage
Add mushrooms
Shrinkwrap pizza
Pack in box
None
A
B
C
D
D
D
E,F,G
H
Total task time
50
5
25
15
12
10
15
18
15
165
Layout Calculations
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Step 2: Determine output rate
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Vicki needs to produce 60 pizzas per hour
Step 3: Determine cycle time
 The amount of time each workstation is allowed to
complete its tasks
Cycle time (sec./unit ) 
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available time sec./day  60 min/hr x 60 sec/min
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 60 sec./unit
desired output units/hr 
60 units/hr
Limited by the bottleneck task (the longest task in a
process):
Maximum output 
available time
3600 sec./hr.
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 72 units/hr, or pizzas per hour
bottleneck task time
50 sec./unit
Layout Calculations
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(continued)
Step 4: Compute the theoretical minimum
number of stations
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TM = number of stations needed to
achieve 100% efficiency (every second is
used)
TM 
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 task times  
cycle time
165 seconds
 2.75, or 3 stations
60 sec/station
Always round up (no partial workstations)
Serves as a lower bound for our analysis
Layout Calculations
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(continued)
Step 5: Assign tasks to workstations
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Start at the first station & choose the longest eligible task following
precedence relationships
Continue adding the longest eligible task that fits without going over the
desired cycle time
When no additional tasks can be added within the desired cycle time, begin
assigning tasks to the next workstation until finished
Workstation
1
2
3
Eligible task
A
B
C
D
E, F, G
E, F
F
H
I
Task Selected
A
B
C
D
G
E
F
H
I
Task time
50
5
25
15
15
12
10
18
15
Idle time
10
5
35
20
5
48
38
20
5
Last Layout Calculation
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Step 6: Compute efficiency and balance delay
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Efficiency (%) is the ratio of total productive
time divided by total time
Efficiency
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t

(%) 

NC
165 sec.
100  91.7%
3 stations x 60 sec.
Balance delay (%) is the amount by which the
line falls short of 100%
Balance delay  100%  91.7%  8.3%
Other Product Layout Considerations
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Shape of the line (S, U, O, L):
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Paced versus un-paced lines
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Share resources, enhance communication &
visibility, impact location of loading &
unloading
Paced lines use an automatically enforced
cycle time
Single or mixed-model lines
Designing Hybrid Layouts
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One of the most popular hybrid layouts uses Group
Technology (GT) and a cellular layout
GT has the advantage of bringing the efficiencies of a
product layout to a process layout environment
Process Flows before the Use of GT Cells
Process Flows after the Use of GT Cells
Chapter 10 Highlights
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Layout planning is deciding on the best physical
arrangement of resources.
There are four basic types of layouts: process,
product, hybrid, and fixed position.
Process layouts provide flexibility to make a
variety of different products. Product layouts
provide greater efficiency for one product.
The steps for designing process layouts are:
gather space and closeness information, develop a
block plan, and develop a detailed layout.
Chapter 10 Highlights
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(continued)
The steps for designing an product layout are:
identify tasks and predecessors, determine output
rate, determine cycle time, computing the
theoretical minimum number of work stations,
assigning tasks to workstations, and computing
efficiency and balance delay.
Hybrids layouts combine elements from both types
of layouts to increase efficiency.
Hybrid layouts combine GT analysis with cellular
layout concepts .
The End
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