MBA 8452 Systems and Operations Management
Facility Layout
Objective: Manufacturing Design


Be able to identify and explain the different Facilities
Layout
Be able to Solve Problems using Assembly Line
Balancing
2
Facility Layout

The physical arrangement of everything
needed for production of goods or services

equipment/machines

raw materials/finished goods storage areas

departments/workstations

aisles and common areas
3
Benefits of Good Layout

Overall, improved effectiveness and
efficiency of the production system

Higher utilization of space, equipment, and people

Improved flow of information, materials, and work

More convenience to the customer

Improved employee morale and working conditions
4
Basic Production Layouts

Process Layout

Product Layout

Group Technology (Cellular) Layout

Fixed-Position Layout
5
Process Layout

Similar activities and machines/operations
are grouped together by functions into
departments or work centers (job shops)

Low-volume high-variety products

Inputs follow different paths for processing

Examples: department stores, universities,
hospitals
6
Process Layout Example:
Manufacturing
Lathe Department
Milling
Department
Drilling Department
L
L
M
M
D
D
D
D
L
L
M
M
D
D
D
D
L
L
G
G
G
P
L
L
G
G
G
P
L
L
Grinding
Department
Receiving and
Shipping
Painting Department
A
A
Assembly
A
7
Process Layout Example:
Service
Women’s
lingerie
Shoes
Housewares
Women’s
dresses
Cosmetics
& Jewelry
Children’s
department
Women’s
sportswear
Entry &
display area
Men’s
department
8
Designing Process Layout

What factors might we consider when
determining the locations of process
areas, or departments?





interdepartmental transportation
material handling costs
space & labor utilization
flexibility
etc.
9
Product Layout

Activities and machines/operations are
arranged sequentially in order by product
specifications (flow shops)

High-volume standardized products

Inputs follow the same path

Examples: assembly lines
10
Product Layout: An Example
IN
OUT
11
Assembly Line Balancing

The Problem: how to organize jobs or tasks
such that each station has the same work
load/time for processing a unit?
task
Station 1
Station 2
1
3
2
5 min/unit
4
Station 3
5
8 min/unit
6
3 min/unit
What’s the problem here?
12
Line Balancing
Example

Task
A
B
C
D
E
F
G
H
You’ve been assigned the job of setting up an electric
fan assembly line with the following tasks:
Time (Mins) Description
2
Assemble frame
1
Mount switch
3.25
Assemble motor housing
1.2
Mount motor housing in frame
0.5
Attach blade
1
Assemble and attach safety grill
1
Attach cord
1.4
Test
Predecessors
None
A
None
A, C
D
E
B
F, G
13
Step 1:
Draw Precedence Diagram

2
A
1
B
1
G
C
D
E
F
3.25
1.2
.5
1
1.4
H
Which process step defines the maximum rate
of production?
14
The Bottleneck
Production time per day
420 mins
Max Production =
=
= 129 units
Bottleneck time
3.25 mins / unit
Task
A
B
C
D
E
F
G
H
Time (Mins)
2
1
3.25
1.2
0.5
1
1
1.4
Description
Assemble frame
Mount switch
Assemble motor housing
Mount motor housing in frame
Attach blade
Assemble and attach safety grill
Attach cord
Test
Predecessors
None
A
None
A, C
D
E
B
F, G
15
Step 2:
Compute Required Cycle Time
Production time per period
Required Cycle Time, C =
Required output per period

If we are required to assembly 100 fans per
day and we know that total production time
per day is 420 mins = 7 hrs  60 min/hr, then
420 mins/day
C=
= 4.2 mins/unit
100 units/day
What does this figure represent?
16
Step 3:Calculate Theoretical
Minimum Number of Stations
Theoretical Min. Number of Workstations,
Sum of task time s (T)
Nt =
Cycle time (C)
11.35 mins/unit
Nt =
= 2.702
4.2 mins/unit
Therefore, Nt = 3 (always round up)
17
Step 4: Use Heuristic Rules
to Assign Tasks to Stations

most-following task rule


Assign tasks in order of the largest number
of following tasks
longest task time rule

Assign tasks in order of the longest task
time
Note: One of these rules can be used as the primary rule
and another as the secondary tie-breaking rule
18
Step 4:Cont.

Task
A
B
C
D
E
F
G
H
If we try the most-followers rule as the
primary rule and the longest task time as
tie-breaking rule
# of followers
6
2
4
3
2
1
1
0
Station
Start
1
2
3
Task
Time
A
B
G
C
D
E
F
H
2
1
1
3.25
1.2
0.5
1
1.4
Time Left Ready Tasks
A, C
2.2
C, B
1.2
C, G
0.2
C
0.95
D
3
E
2.5
F
1.5
H
0.1
None
19
Step 5:
Evaluate Efficiency of the Line
Sum of task times (T)
Efficiency =
Actual number of workstations (Na) x Cycle time (C)
11.35 mins / unit
Efficiency =
=.901
(3)(4.2mins / unit)
Note: If efficiency is unsatisfactory, rebalance
using another rule to improve efficiency
20
Example:
Some Further Questions
 What is the effective/achieved cycle time?
Answer: 4.1 mins.
 What is the idle time of station 1? Total idle
time of the assembly line?
Answer: 0.2 mins and 1.25 mins, respectively
 Which station is the bottleneck?
Answer: station 3
21
Product vs. Process Layouts
PRODUCT LAYOUT
1. Description
2. Process
3. Product
Sequential arrangement
of machines
Continuous, mass prod.
Standardized, make-to-stock
PROCESS LAYOUT
Functional grouping
of machines
Intermittent, job shop
Varied, make-to-order
4. Demand
Stable
Fluctuating
5.
6.
7.
8.
9.
High
Special purpose
Limited skills
Fixed path (conveyor)
Equalize work at
each station
Efficiency
Low
General purpose
Varied skills
Variable path (forklift)
Minimize material
handling cost
Flexibility
Volume
Equipment
Workers
Material handling
Goal
10. Advantage
22
Retail Service Layout


Goal--maximize net profit per square foot
of floor space
Humanistic considerations

Ambient Conditions

Spatial Layout and Functionality

Signs, Symbols, and Artifacts
23
Fixed Position Layout

What our our primary considerations for
a fixed position layout?
24
Group Technology:
Cellular Layout

Dissimilar machines are grouped into work
centers (cells) to process products with
similar shapes and processing
requirements
25
Cellular Layout Example:
Original Process Layout
Assembly
4
6
7
5
8
2
1
A
10
3
B
9
C
12
11
Raw materials
26
Cellular Layout Example:
Part Routing Matrix
Parts
A
B
C
D
E
F
G
H
1
x
2
x
3
4
x
Machines
5
6
7
x
x
x
x
x
10
x
11
12
x
x
x
x
x
x
x
x
x
x
9
x
x
x
8
x
x
x
x
x
x
x
x
27
Cellular Layout Example:
Cell Formation
Parts
A
D
F
C
G
B
H
E
1
x
x
x
2
x
x
4
x
x
x
8
x
x
x
Machines
10 3
6
x
x
x
x
x
x
9
5
11
12
x
x
x
x
x
x
x
x
x
x
7
x
x
x
28
Cellular Layout Example:
Revised Layout with Three Cells
Assembly
8
10
9
12
11
4
Cell1
Cell 2
6
Cell 3
7
2
Raw materials
1
3
A
C
5
B
29