craft & aldep

An Example of CRAFT

Product, Process & Schedule Data

Product Processingsequence

Dailyproduction

No of itemsin Trolley

Trolley loads/ day

1 ABCBCD 100 5 20

2 ACBD 50 5 10

3 ACBCBD 200 40 5

Initial Layout

A D

B C

From/To

A B C D

A --- 1 2 1

B 1 --- 1 2

C 2 1 --- 1

D 1 2 1 ---

Distance Matrix for initial layout(Assuming Rectilinear Distances)

Load MatrixFrom/To A B C D

A --- 20 15

B --- 45 15

C 45 --- 20

D ---

Unit Cost MatrixFrom/To A B C D

A --- 1 2 1

B 1 --- 1 1

C 2 1 --- 1

D 1 1 1 ---

Load x Unit Cost Matrix (Flow Matrix)

From/To

A B C D

A --- 20 30 50

B --- 45 15 60

C 45 --- 20 65

D --- 00

00 65 75 35

Initial Layout (Distance Matrix)

A D

B C

From/To

A B C D

A --- 1 2 1

B 1 --- 1 2

C 2 1 --- 1

D 1 2 1 ---

Material Handling Effort for Initial Layout

From/To

A B C D

A --- 20 30

B --- 45 15

C 45 --- 20

D ---

From/To

A B C D

A --- 1 2 1

B 1 --- 1 2

C 2 1 --- 1

D 1 2 1 ---

From/To

A B C D

A --- 20 60 80

B --- 45 30 75

C 90 --- 20 110

D --- 00

00 110 105 50 265

P air w ise E x chang es

A BB DA C

A CC DB A

A DD AB C

B CA DC B

B DA BD C

C DA CB D

In it ia l L ayou tA DB C

265 Material Handling Effort

Alternative 1 (Distance Matrix)

A B C D

A ---- 1 1 2

B 1 ---- 2 1

C 1 2 ---- 1

D 2 1 1 ----

B DA C

Material Handling Effort = Flow x Distance Matrix = 220

Alternative 2 (Distance Matrix)

A B C D

A ---- 1 2 1

B 1 ---- 1 2

C 2 1 ---- 1

D 1 2 1 ----

C D B A

Material Handling Effort = Flow x Distance Matrix = 265

Alternative 3 (Distance Matrix)

A B C D

A ---- 2 1 1

B 2 ---- 1 1

C 1 1 ---- 2

D 1 1 2 ----

D AB C

Material Handling Effort = Flow x Distance Matrix = 215

Alternative 4 (Distance Matrix)

A B C D

A ---- 2 1 1

B 2 ---- 1 1

C 1 1 ---- 2

D 1 1 2 ----

A DC B

Material Handling Effort = Flow x Distance Matrix = 215

Alternative 5 (Distance Matrix)

A B C D

A ---- 1 2 1

B 1 ---- 1 2

C 2 1 ---- 1

D 1 2 1 ----

A BD C

Material Handling Effort = Flow x Distance Matrix = 265

Alternative 6 (Distance Matrix)

A B C D

A ---- 1 1 2

B 1 ---- 2 1

C 1 2 ---- 1

D 2 1 1 ----

A CB D

Material Handling Effort = Flow x Distance Matrix = 220

P air w ise E x chang es

A BB DA C

A CC DB A

A DD AB C

B CA DC B

B DA BD C

C DA CB D

In it ia l L ayou tA DB C

265

220 265 215* 215* 265 220

MaterialHandlingEffort

Summary of the CRAFT procedure

• This example demonstrates one iteration of the basic CRAFT procedure

• The best layout so produced is compared with the starting layout. If it is inferior to the starting layout, the starting layout is declared optimal and the search stops

• Otherwise a new iteration with the discovered layout as the starting node is initiated

An Example of ALDEP

The Available Space

B

Placement of 1st Department

Placement of 2nd Department

B

D

D

Placement of 3rd Department

B

D

D

A

Placement of 4th Department

B

D

D

A

C

CC

Final Layout

B

D

D

A

C

CC