This chapter discusses facility layout planning and different types of layouts. It describes the key steps to designing process layouts, which include gathering information, developing alternative plans, and creating a detailed layout. For product layouts, the steps are identifying tasks and predecessors, determining output rate, cycle time, workstations, assigning tasks, and calculating efficiency. Hybrid layouts combine aspects of process and product layouts, such as group technology which organizes production into cells of similar products.

1. © Wiley 2010 1
Chapter 10 – Facility Layout
Operations Management
by
R. Dan Reid & Nada R. Sanders
4th Edition © Wiley 2010

2. © Wiley 2010 2
Learning Objectives
 Define layout planning and explain its importance
 Identify and describe different types of layouts
 Compare process layouts & product layouts
 Describe the steps involved in designing a process layout
 Describe the steps involved in designing a product layout
 Explain the advantages of hybrid layouts
 Define the meaning of group technology (cell) layouts

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Layout Planning
Layout planning is deciding the best physical arrangement
of all resources that consumes space within a facility
 Facility resource arrangement can significantly affect
productivity and quality of products/services
 Two broad categories of operations:
 Intermittent processing systems – low volume of many different
products
 Continuous processing systems – high volume of a few
standardized products

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Types of Layouts
Four basic layout types consisting of:
 Fixed-Position layouts - Product is too large to move;
e.g. a building
 Process layouts - Group similar resources together
 Product layouts - arrange activities according to
sequence of operations for a particular product/service
 Hybrid layouts - Combine aspects of both process and
product layouts

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5
Underlying Process Relationship
Between Volume and Standardization
Continuum

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Fixed-Position Layout
 Used when product is large
 Product is difficult or impossible to move,
i.e. very large or fixed
 All resources must be brought to the site
 Scheduling of crews and resources is a
challenge

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Process Layout in Services
Women’s
lingerie
Women’s
dresses
Women’s
sportswear
Shoes
Cosmetics
and jewelry
Entry and
display area
Housewares
Children’s
department
Men’s
department

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Manufacturing Process Layout
L
L
L
L
L
L
L
L
L
L
M
M
M
M
D
D
D
D
D
D
D
D
G
G
G
G
G
G
A A A
Receiving and
Shipping Assembly
Painting Department
Lathe Department
Milling
Department Drilling Department
Grinding
Department
P
P

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A Product Layout
In
Out

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Process vs. Product Layouts
Here are the characteristic differences between a process
and product layout.

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Hybrid Layouts
 Combine elements of both product &
process layouts
 Maintain some of the efficiencies of product
layouts
 Maintain some of the flexibility of process
layouts
 Examples:
 Group technology & manufacturing cells
 Grocery stores

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Original Process Layout
C
A B Raw materials
Assembly
1
2
3
4
5
6 7
8
9
10
11
12

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Revised Cellular Layout
3
6
9
Assembly
1
2
4
8 10
5
7
11
12
A C B
Raw materials
Cell 1 Cell 2 Cell 3

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Designing Process Layouts
Step 1: Gather information:
Space needed, space available, identify closeness
measures
Step 2: Develop alternative block plans:
Using trial-and-error or decision support tools
Step 3: Develop a detailed layout:
Consider exact sizes/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

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Computerized layout
Solutions
 CRAFT
 Computerized Relative Allocation of Facilities
Technique
 CORELAP
 Computerized Relationship Layout Planning
 PROMODEL and EXTEND
 visual feedback
 allow user to quickly test a variety of scenarios
 Three-D modeling and CAD
 integrated layout analysis
 available in VisFactory and similar software

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Designing Service
Layouts
 Must be both attractive and functional
 Types
 Free flow layouts
 encourage browsing, increase impulse purchasing, are flexible
and visually appealing
 Grid layouts
 encourage customer familiarity, are low cost, easy to clean
and secure, and good for repeat customers
 Loop and Spine layouts
 both increase customer sightlines and exposure to products,
while encouraging customer to circulate through the entire
store

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Types of Store Layouts

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Designing Product Layouts
 Designing product layouts requires
consideration of sequence of tasks to be
performed by each workstation in a logical
order
 Goal: Maximize production capacity, i.e., the
line must be as balanced as possible

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Flow Time vs Cycle Time
 Cycle time = max time spent at any station
 Flow time = time to complete all stations
1 2 3
4 minutes 4 minutes 4 minutes
Flow time = 4 + 4 + 4 = 12 minutes
Cycle time = max (4, 4, 4) = 4 minutes

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Designing Product Layouts –
con’t
Step 1: Identify tasks & immediate predecessors
Step 2: Determine output rate
Step 3: Determine cycle time
Step 4: Compute the Theoretical Minimum number of
Stations
Step 5: Assign tasks to workstations (balance the
line)
Step 6: Compute efficiency, idle time & balance delay

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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 Roll dough None 50
B Place on cardboard backing A 5
C Sprinkle cheese B 25
D Spread Sauce C 15
E Add pepperoni D 12
F Add sausage D 10
G Add mushrooms D 15
H Shrinkwrap pizza E,F,G 18
I Pack in box H 15
Total task time 165

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Layout Calculations
 Step 2: Determine output rate
 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
 Limited by the bottleneck task (the longest task in a
process):
 
 
sec./unit
60
units/hr
60
sec/min
60
x
min/hr
60
units/hr
output
desired
sec./day
time
available
)
(sec./unit
time
Cycle 


hour
per
pizzas
or
units/hr,
72
sec./unit
50
sec./hr.
3600
time
task
bottleneck
time
available
output
Maximum 



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Layout Calculations (continued)
 Step 4: Compute the theoretical minimum
number of stations
 TM = number of stations needed to
achieve 100% efficiency (every second is
used)
 Always round up (no partial workstations)
 Serves as a lower bound for our analysis
 
stations
3
or
2.75,
n
sec/statio
60
seconds
165
time
cycle
times
task
TM 




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Layout Calculations (continued)
 Step 5: Assign tasks to workstations
 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 Eligible task Task Selected Task time Idle time
A A 50 10
B B 5 5
C C 25 35
D D 15 20
E, F, G G 15 5
E, F E 12 48
F F 10 38
H H 18 20
I I 15 5
1
2
3

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Layout Calculations (Continued)
 Step 6: Compute efficiency and balance delay
 Efficiency (%) is the ratio of total productive
time divided by total time
 Balance delay (%) is the amount by which the
line falls short of 100%
  91.7%
100
sec.
60
x
stations
3
sec.
165
NC
t
(%)
Efficiency 



8.3%
91.7%
100%
delay
Balance 



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Other Product Layout Considerations
 Shape of the line (S, U, O, L):
 Share resources, enhance communication & visibility,
impact location of loading & unloading
 Paced versus unpaced lines
 Paced lines use an automatically enforced cycle time
 Number of Product Models produced
 Single
 Mixed-model lines

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Group Technology (CELL)
Layouts
 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

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Process Flows before the Use of GT Cells

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Process Flows after the Use of GT Cells

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Chapter 10 Highlights
 Layout planning is deciding on the best physical arrangement of all
resources within a facility. There are four basic types of layouts: process,
product, hybrid, and fixed position.
 Process layouts provide more flexibility while product layouts provide
greater efficiency.
 The steps for designing process layouts are (1) gather information about
space needs, space availability, and closeness requirements of departments;
(2) developing a block plan or schematic of the layout; and (3) developing a
detailed layout.
 The steps for designing an product layout are (1) identify tasks that need to
be performed and their immediate predecessors; (2) determine output rate;
(3) determine cycle time; (4) computing the theoretical minimum number of
work stations, (5) assigning tasks to workstations; and (6) computing
efficiency and balance delay.
 Hybrids layouts (e.g., group technology or cell layouts) combine elements of
both process and product layouts to increase efficiency. Group technology
first groups products based on similar processing requirements. Cells are
created for each grouping of products, resulting in a more orderly flow of
products through the facility.