Facility Design-Week 9
Computerized Layout Planning
By
Anastasia L. Maukar
1
Computerized Layout Planning
• Focus on how computers can aid the facility layout
process.
• Designer must interact with multiple design
databases and provide the integration between them
to translate information and ensure consistency.
2
Computerized Layout Planning
• Concentrate on decision aids for block layout
planning.
– Information required
– Common elements
– “Classical” layout programs
• Craft, Corelap, Aldep, and Planet
– “Newer” layout programs
• M-Craft, LayOpt, FactoryPlan
3
Computerized Layout Planning
• Information in layout planning
– Numeric information
• Space required for an activity
• Total flow between two activities
– Logic information
• Preferences of the designer, i.e., activity relationship
chart
– Graphical information
• Drawing of the block plan
4
Computerized Layout Planning
• Key element of computerized layout planning is
the representation and manipulation of these
three types of information.
– Graphical representation is most challenging. A
method suitable for display is not suitable for
manipulation and vice-versa.
5
Computerized Layout Tech’
• Computerized Layout Technique
– A Layout Construction Procedure: ALDEP,
CORELAP
– A Layout Improvement Procedure, CRAFT
•
•
•
•
•
Distance Between Two Departments
Total Distance Traveled
Savings and a Sample Computation
Improvement Procedure
Exact Centroids
6
Computerized Layout Technique
• Suppose that we are given some space for some departments.
How shall we arrange the departments within the given space?
• We shall assume that the given space is rectangular shaped and
every department is either rectangular shaped or composed of
rectangular pieces.
• We shall discuss
– a layout improvement procedure, CRAFT, that attempts to find
a better layout by pair-wise interchanges when a layout is given
and
– a layout construction procedure, ALDEP/CORELAP, that
constructs a layout when there is no layout given.
7
ALDEP
Automated Layout Design Program
• ALDEP is a construction procedure.
• ALDEP does not need any initial layout. ALDEP
constructs a layout when there is none.
• Given
–
–
–
–
–
Size of the facility
The departments
Size of the departments
Proximity relationships (activity relationship chart) and
A sweep width (defined later)
8
ALDEP
• Use: vertical scanning pattern
• 2 disadvantages: scoring method and the fixed values
assigned to the closeness ratings.
• The size of the facility and the size of the departments
are expressed in terms of blocks.
• Score is determined using the numerical values
assigned to the closeness rating).
A = 43 = 64
I = 41 = 4
U=0
E = 42 = 16
O = 40 = 1 X = –45 = –1.024
9
ALDEP
Production area
O
Office rooms
A
U
I
O
Storage
A
Dock area
X
U
U
U
Figure 1. ARC
A
U
O
O
Locker room
Tool room
E
A: absolutely necessary
E: especially important
I: important
O: ordinarily important
U: unimportant
X: undesirable
10
ALDEP
• The procedure will be explained with an example. Suppose that the
facility is 8 blocks (horizontal)  6 block (vertical).
• The departments and the required number of blocks are:
–
–
–
–
–
–
Production area (P)
Office rooms (O)
Storage area (S)
Dock area (D)
Locker room (L)
Tool room (T)
14 blocks
10
8
8
4
4
11
ALDEP
• The proximity relationships are shown as figure 1.
• ALDEP starts to allocate the departments from
the upper left corner of the facility. The first
department is chosen at random.
• By starting with a different department, ALDEP
can find a different layout for the same problem.
12
ALDEP
• Let’s start with dock rooms (D). On the upper left corner 8
blocks must be allocated for the dock area.
• The sweep width defines the width in number of blocks. Let
sweep width = 2. Then, dock area will be allocated 2  4 =
8 blocks.
D D
D D
D D
D D
13
ALDEP
• To find the next department to allocate, find the
department that has the highest proximity rating
with the dock area (D). Storage area (S) has the
highest proximity rating A with the dock area.
• So, the storage area will be allocated next. The
storage area also needs 8 blocks.
14
ALDEP
• There are only 2 2 = 4 blocks, remaining below dock
area (D). After allocating 4 blocks, the down wall is hit
after which further allocation will be made on the
adjacent 2 (=sweep width) columns and moving
upwards.
D D
D D
D D
D D
S S S S
S S S S
15
ALDEP
• See carefully that the allocation started from the upper
left corner and started to move downward with an width
of 2 (=sweep width) blocks.
• After the down wall is hit, the allocation continues on the
adjacent 2 (=sweep width) columns on the right side and
starts moving up.
• This zig-zag pattern will continue.
• Next time, when the top wall will be hit, the allocation
will continue on the adjacent 2 (=sweep width) columns
on the right side and starts moving down.
16
ALDEP
• To find the next department to allocate, find the department
that has the highest proximity rating with storage area.
Production area (P) has the highest proximity rating A with the
storage area.
• The production area (P) needs 14 blocks.
• After allocating 8 blocks, the
top wall is hit and the
remaining 6 blocks are
allocated on the adjacent 2
(=sweep width) columns
moving downward.
D D P P P P
D D P P P P
D D P P P P
D D P P
S S S S
S S S S
17
ALDEP
• To find the next department to allocate, find the department
that has the highest proximity rating with production area.Tool
room (T) has the highest proximity rating A with the production
area.
• The tool room needs 4 blocks.
• Next, there is a tie, both locker
room (L) and office room (O)
has the same proximity rating of
U with the tool room.
• Ties are broken at random. So,
any of the locker room or the
office room can be allocated
next.
D D P P P P
D D P P P P
D D P P P P
D D P P T T
S S S S T T
S S S S
18
ALDEP
• Let’s choose locker room (L) room at random. Then, the last
department must be office room (O). The resulting layout is
shown below.
• Note that since the ALDEP chooses the first department at
random and since the ties are broken at random, ALDEP can
give many solutions to the same problem.
• Using the layout, the adjacency
relationships and the proximity
ratings, we can find an overall
rating of each layout. Then, the
layout with the highest overall
rating is selected.
D D P P P P O O
D D P P P P O O
D D P P P P O O
D D P P T T O O
S S S S T T O O
S S S S L L L L
19
ALDEP
• After a layout is obtained, a score for the layout is
computed with the following conversion of proximity
relationships:
A = 43
I
= 41
U = 0,
= 64,
E
= 42
= 16
= 4,
O
= 40
=1
X
= -45 = -1024
• If two departments are adjacent in the layout then the
weight corresponding to the rating between the two
departments is added to the score.
20
ALDEP
•
Let’s compute the overall rating of the layout
constructed.
1. Make a list every pair of adjacent departments.
2. For each pair, a letter rating will be obtained from the
activity relationship chart (see figure 1)
3. Convert the score into a numeric score using the
conversion scheme on the previous slide.
21
ALDEP
• Adjacent departments:
(D,S)
(D,P)
(S,P)
(S,T)
(S,L)
(P,T)
(P,O)
(T,L)
(T,O)
(L,O)
D D P P P P O O
D D P P P P O O
D D P P P P O O
D D P P T T O O
S S S S T T O O
S S S S L L L L
22
ALDEP
Adjacents Proximity
Dept
Ratings
Value Score
(D,S)
A
64
128
(D,P)
I
4
8
(S,P)
A
64
128
(S,T)
O
1
2
(S,L)
U
0
0
(P,T)
A
64
128
(P,O)
O
1
2
(T,L)
U
0
0
(T,O)
U
0
0
(L,O)
X
-1024 -2048
-763 -1526
23
ALDEP
• The process is repeated several times and the layout
with the highest score is chosen.
• Notice the large negative weight associated with X
ratings.
• If the departments which cannot be next to each other,
are adjacent in a layout, then the layout score reduces
significantly.
• This is important because ALDEP also uses a cut-off
score (if not specified by the user this cut-off is zero) to
eliminate any layout which has a layout score less than
the cut-off score.
24
CORELAP
• Uses Relationship Chart as input (REL)
• Requires users to assign weights to the alphabetic
ratings in the REL chart . (Closeness Ratings)
• Computes the total closeness ratings (TCR) for each
department by summing all the CR associated with
that department.
• Values selected for ratings are important
25
CORELAP
Importance of Closeness
Line
code
Numerical
weights
Value
Closeness
A
Absolutely necessary
32
E
Especially important
26
I
Important
8
O
Ordinary closeness OK
4
U
Unimportant
2
X
Undesirable
-32
CORELAP - STEPS
1.
Selection Procedure
2.
Placement and Evaluation Procedure
27
CORELAP – STEP 1
• First department:
max TCRi
i
Where:
m
TCR
i

 [V(r
ij
)]
j 1
• Second department:
– X-relation  “last placed department”
– A-relation with first. If none E-relation with
first, etcetera
28
CORELAP – Tie Breaker Rules
• Highest TCR
• Largest Area
• Lowest Dept. Number (random)
29
CORELAP – STEP 2
• Department areas are converted into grid
squares.
• CORELAP does not take the building shape
into account.
• The final shape of the facility created by
CORELAP depends on the placement of
departments it has selected.
30
CORELAP – STEP 2
• Place the first department in the center of the layout
• Subsequent department is placed abutting already
placed departments in the position that gives the best
placement rating
• After the layout is completed CORELAP calculates a
numerical score for the layout
LayoutScor e 
  CR
i
ji
ij
 d ij
31
CORELAP – STEP 2
8
7
6
1
1st
5
2
3
4
2nd
32
Example of Dept Placements
Contoh: Dept. 1, 2, 3 sudah diletakkan di layout dan dept. 4 akan
diletakkan. Weighted Rating: (assigned by the user)
A = 600 E = 200 I = 50 O = 10 U = 0 X = –200
3
3
3
4
2
1
2
2
1
3
3
3
4
4
2
800
(a)
2
1 - 4: A
2 – 4: E
3 – 4: I
650
(b)
1
4
3
(c)
850
33
Procedure to Place Departments
• Assume that a department is
placed in the middle (position
0). Then, if another department
8
8
7
6
71
0
56
2
3
4
1
Pusat
5
2
3
4
is placed in position 1, 3, 5 or 7,
it is “fully adjacent” with the
first one. It is placed in position
2, 4, 6 or 8, it is “partially
adjacent”.
34
Procedure to Place Departments
• For each position, Weighted Placement (WP) is the sum of the
numerical values for all pairs of adjacent departments.8 7 6
1 0 5
• The placement of departments is based on the following steps:
2
3
4
1. The first department selected is placed in the middle.
2. The placement of a department is determined by evaluating all
possible locations around the current layout in counterclockwise
order beginning at the “western edge”.
3. The new department is located based on the greatest WP
value.
35
Example - CORELAP
CV values:
V(A) = 125
V(E) = 25
V(I) = 5
V(O) = 1
V(U) = 0
V(X) = -125
1. Receiving
A
2. Shipping
A
E
3. Raw Materials Storage
E
A
E
4. Finished Goods Storage
A
5. Manufacturing
U
A
8. Offices
9. Maintenance
Partial adjacency:
 = 0.5
U
E
A
E
U
O
A
O
X
O
E
U
A
A
U
A
A
U
O
O
7. Assembly
U
U
E
6. Work-In-Process Storage
O
O
A
X
36
Table of TCR Values
D ep a rtm en t
S u m m a ry
D ep t.
TCR
O rd er
1
2
3
4
5
6
7
8
9
A
E
I O
U
X
1
-
A
A
E
O
U
U
A O
3
1
0
2
2
0
402
(5 )
2
A
-
E
A U
O
U
E
A
2
2
0
1
3
0
301
(7 )
3
A
E
-
E
A
U
U
E
A
3
3
0
0
2
0
450
(4 )
4
E
A E
-
E
O
A
E
U
2
4
0
1
1
0
351
(6 )
5
U
O A
E
-
A
A
O
A
4
1
0
2
1
0
527
(2 )
6
U
O U O
A
-
A
O
O
2
0
0
4
2
0
254
(8 )
7
U
U U
A A
A
-
X
A
4
0
0
0
3
1
625
(1 )
8
A
E
E
O O
X
-
X
1
3
0
2
0
2
452
(9 )
9
O U A
A
X
-
3
0
0
2
2
1
502
(3 )
E
U A
O
37
Example (cont.)
62.5
187.5 187.5
62.5
62.5
125
62.5
125
7
125
125
62.5
125
62.5
62.5 187.5 187.5
62.5
63.5
1
0
5
7
0
9
1.5
0
1
0.5
5
62.5
125
62.5
0
62.5 125.5
187.5
5
7
0
125
187.5
9
187.5
0
62.5
125
62.5
3
62.5 126.5
0.5
7
125
38
Example (cont.)
12.5 37.5 100 137.5 62.5
37.5
3
5
37.5
1
9
12.5
25
12.5
12.5
25
125
87.5
3 5
137.5 62.5
137.5
7
0
1
62.5 125
0
62.5 125
12.5
0
0
7
62.5
9 4
125
125
125
62.5
188 62.5
0.5
1
3
5
7
125
1
2
1
9
4
63.5
0.5
1
1
1.5
1.5
0.5
39
Example (cont.)
0.5
1
0.5
12.5 25.5 -60.5
6
-61.5
3
5
7
-112
8
3
5
7
1
9
4
-37.5
2
1
9
4
12.5 112.5
25
2
12.5 87.5
75
6
-62.5 -37.5 12.5
40