1. Computerized Relative Allocation of Facilities Technique
CRAFT
Computerized Relative Allocation of Facilities Technique
Created by Lorna StJohn
For Operations Management 345
Professor Tom Foster
Wednesday, May 08, 2002

2. What Will Be Covered Definition of CRAFT Brainstorming Nuts and Bolts
How it Works
An Exercise
Summary
Reading List

3. CRAFT Defined Created in 1964 by Buffa and Armour
Process layout approach
A heuristic computer program
Compares process departments
CRAFT is a tool used to help improve the existing layout of the facilities. The facility is improved by switching two or three departments to help arrange the facility in an optimal floor plan. This procedure requires the following inputs: From-To Chart, Cost Matrix, Distances (determined for a given layout) and an Initial layout. Craft is used when the number of departments is so large that the computation by hand would be very intensive and make the improvement not worth the time for many companies.
Process Layout – also known as a functional layout is usually used in job shops or a batch production facility. In this layout, activities are grouped together in work centers or departments according to the process or function they perform. The goal of process layout is to minimize the material handling costs in manufacturing. The departments that incur the most interdepartmental movement should be located the closest to on another.
Advantages – Flexibility
Disadvantages –
Inefficient – Jobs do not flow through in an orderly fashion, therefore backtracking occurs often.
Idle time – More idle time may be experienced while workers are waiting for more work to arrive from different departments
Heuristics – An algorithm that returns good results but not necessarily the optimal result for the layout. CRAFT uses a pairwise exchange algorithm that may not return the optimal result because the final solution depends on the initial layout of the plant.

4. Brainstorming Exercise
Think of the amount of handling a product will have from one department to another in your company.
Does the product have to travel across many departments to get to the next step in the process?
The purpose of this is to get people to determine if it would be beneficial to interchange departments to reduce the handling of the product.

5. End Task Minimize Transportation Costs Improve Work Flow
Utilize labor efficiently
Utilize space efficiently
Eliminate bottlenecks

6. Nuts and Bolts Initial Layout
Initial Layout of Departments
Dept A
Dept B
Dept C
Dept D
Dept E A B C D E
This is the initial layout of the departments in the facility. There may be dummy or fixed departments that show areas of the facility that are unusable space and/or cannot be moved. The next step is to create a From-To chart.

7. Nuts and Bolts From-To Chart
D E PA R T M E N T
Department 1 2 3 4 5 -
100 50
200 60 40
From-To chart – This shows the average number of units/loads moved between departments. After you have created this chart for the layout you will do the computations to determine the moment of the matrix.

8. Nuts and Bolts From-To Chart
Determines which of the two departments has a better from-to matrix, we can calculate the moment of the matrix as follows:
After creating the computations you will compare each combination of matrixes to determine which has the lowest number. the lowest number determine the most optimal layout. Once you have determined the optimal matrixes you will lay out the departments in a block diagram to get the best fit.

9. Nuts and Bolts Block Diagramming
Initial Diagram Final Diagram
Block Diagramming is done to get the departments to fit in the plant once the optimal layout has been determined. When evaluating an interchange of departments the departments must have the same area and share a common boundary. This process it repeated until there is no two-way interchange that will result in an improvement.

10. Benefits and Problems Benefit Problems A Computer Program Flexibilty
Greedy Algorithm
Inefficient
End result may need to be modified
A greedy algorithm is one that always takes the best immediate solution
In a job shop the flow through the system is not always constant and causes fluctuations in the process
Once CRAFT has determined a solution it may need to be massaged to create a layout that fits in the plant

11. An Exercise From-To Chart A B C D E - 100 50 200 60 40 From \ To
D E PA R T M E N T
Department A B C D E -
100 50
200 60 40
Have Project team break up into group of 3. Using this chart and the algorithm in the presentation have the groups complete the computation and the determine if any of the departments should be interchanged. Also have them give an explanation for the interchange of the departments or a defense for not needing any changes if that is what they discover.

12. An Exercise cont’d Initial Layout A B C D E
After the computations are completed the groups should try to determine if the conclusions they came to are improvements to the current layout which is on this slide.

13. Summary
It is beneficial to use CRAFT but you should also realize that the program is not flawless.
The user must understand how the program works of the end product is not as efficient as you had hope.

14. Bibliography http://www.cbpa/ewu/edu/~pnemetzmills/OMch7/OM07FAC.html
“Operations management-Focusing on Quality and Competitiveness”
“POM 6”
“Facility Layout”
“Layout Design and Analysis Software” IIE Solutions magazine Grajo, Eric s. Montreuil, Benoit. Sly, Dave.
“CRAFT”

15. Bibliography
“Computerized Relative Allocation of Facilities Technique - CRAFT”
“Measuring Flow”
“IET 409 Plant Layout Class Notes – Chapter 7”
“greedy algorithm”