IPS Topic 4: Process-based facility layout
Discussion questions
D1. The overall objective of a good layout is to obtain the max. efficiency and effectiveness from the
operational resources available. Some specific objectives are:
• To improve the flow of people or goods by reducing bottlenecks
• To minimize material handling costs
• To utilise available space efficiently
• To provide operational flexibility
• To reduce hazards
• To facilitate coordination
D2.
• The flowline layout (also referred to as layout be product, production line or assembly line)
involves arranging the necessary activities in some type of line along which product-in-process
moves. An automobile assembly line is an example.
• Process-based layout is the grouping of all people and equipment that perform the same function
in one location or department. Examples include machine shop, press shop, plastic injection
moulding shop.
• Fixed position layout involves bringing people and equipment to the item being produced.
Examples are shipbuilding, construction of buildings.
D3. Cellular manufacturing is the division of part or all of a plant into small groups of people and
equipment called cells using the concept of Group Technology (GT). Each cell produces a family of
parts which are similar in some aspects, eg. process plans.
Cellular manufacturing can achieve many of the advantages of flowline layout in the production of
similar parts.
D4. A U-line consists of a group of processing equipment that are arranged in the shape of a narrow
U. The operator’s side of all the machines face the inside of the U. The equipment are used to
manufacture a family of parts or sub-assemblies.
The advantage of this arrangement is that an operator with multiple skills can operate several
machines with minimal movements.
D5. Volume is the biggest factor in the development of a layout. Generally, as volume increases, so
does the cost effectiveness of flowline production.
Flexibility is a factor that would favor a process-based layout.
Other factors include the weight of the item being produced, the cost of the equipment and the product
mix to share the equipment.
Problems
P1
One feasible solution is
C
B
A
D
E
F
Other solutions are possible by switching the order of the rows or the columns.
P2
Objectives are 3 near 4, 3 near 5, 2 near 5, 2 near 4, 1 near 5, and 1 near 6.
Other objectives are 1 away from 4, 3 away from 6, 4 away from 6, and 3 away from 1.
Some feasible layouts are:
3
4
or
4
3
or
1
6
or
6
1
5
2
1
6
2
5
6
1
5
2
3
4
2
5
4
3
P3
The objective is to calculate the total cost between two work centres (eg. From A to B and from B to
A), then the costs between workcentres are used as the criterion for layout.
Using the expected number of trips between workcentres, and the cost per unit distance, the cost of
trips is shown below
To
From
A
B
C
D
E
A
0
18
11
6
32
B
20
0
2.75
9
8
C
30
14.4
0
36
14.4
D
20
10.8
8.8
0
16
E
15
16.2
16.5
12
0
The combined cost between centres (e.g., A to B and B to A) is shown below
To
From
A
B
C
D
E
A
B
C
D
E
38
0
41
17.15
0
26
19.80
44.80
0
47
24.20
30.90
28
0
The precedence requirements (in descending order) are A near E, C near D, A near C, A near B, C
near E, D near E, A near D, B near E, B near D, and B near C.
A feasible layout on a square matrix is
Dr Yousef Amer – School of Engineering
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University of South Australia
B
A
C
E
D
P4
One feasible solution is
8
3
1
2
6
5
4
7
9
P6
To
From
A
B
A
0
(0)
216
(0.18)
Data
B
217*
(0.15)*
0
(0)
C
418
(0.15)`
52
(016)
D
61
(0.15)
190
(0.15)
E
100
(0.15)
150
(0.15)
C
400
(0.15)
16
(0.18)
0
(0)
114
(0.15)
421
(0.15)
200
(0.15)
0
(0)
62
(0.15)
0
(0)
95
(0.15)
0
(0)
300
(0.15)
200
(0.15)
300
(0.15)
0
(0)
D
E
Transport cost per month per unit distance from 1 workshop to another
To
From
A
B
C
D
E
A
B
C
D
E
0
38.9
60
2.9
0
32.6
0
17.1
63.2
30
62.7
8.3
0
9.3
0
9.15
28.5
14.3
0
45
15
22.5
30
45
0
Nearness Matrix (transport cost per month per unit distance between workshops)
Between
A
B
C
D
E
A
0
B
71.5
C
122.7
25.4
0
0
D
12.05
91.7
23.6
0
E
15
52.5
30
90
0
It can be seen from the nearness matrix than the priority is as follows:
1. A & C
2. B & D
3. D & E
and so on.
Dr Yousef Amer – School of Engineering
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University of South Australia