1. Introduction Basic Concepts and Definitions
Facility Layout
Introduction
Basic Concepts and Definitions

2. What defines a good layout?
Right equipment
Right method
Right place
Effective processing
Shortest distance
Discuss other ides with class.
Westinghouse definition:
Placing the right equipment, coupled with the right method, in the right place. Permit product processing in the most effective manner, through the shortest possible distance, in the shortest possible time.
Shortest time

3. Production systems correlate to the necessary type of layout.
Product Layout
High
Group Technology Layout
Production Volume
Medium
Fixed Location Layout
Process Layout
This slide is review from the production systems design.
Low
Low
Medium
High
Product Variety

4. Effective Flow is achieved by maximizing directed flow paths.
A directed flow path is an uninterrupted flow path progressing directly from origin to destination:
Uninterrupted flow paths
Interrupted flow paths

5. How do we measure flow? Quantitatively: From-to Chart
Qualitatively: Relationship (REL) Chart

6. From – To Chart Assembly Warehouse Milling Turning Stores Press Plate
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1 – – – – – 7
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7. Relationship (REL) Chart
Code Reason
Frequency of use high
Frequency of use medium
Frequency of use low
Information flow high
Information flow medium
Information flow low
1. Directors conference room
2. President
3. Sales department
4. Personnel
5. Plant manager
6. Plant engineering office
7. Production supervisor
8. Controller office
9. Purchasing department I 1 O 5 U 6 A 4
O 5 3 E 2
Rating Definition
A Absolutely Necessary
E Especially Important
I Important
O Ordinary Closeness OK
U Unimportant
X Undesirable

8. Early Approaches to Layout Design
Apple’s Plant Layout Procedure (1977) (p.303)
Reed’s Plant Layout Procedure (1961) (p.304)
Muther’s Systematic Layout Planning (SLP) Procedure (1973) (pp )
Check page numbers with new book.

9. Input data and activities
SLP - Analysis
Input data and activities
From-To Chart
Flow of
Materials
2. Activity
Relationships
REL Chart
3. Relationship
Diagram
4. Space
Requirements
5. Space
Available

10. SLP – Search and Selection
From Analysis
6. Space
Relationship
Diagram
7. Modifying
Considerations
8. Practical
Limitations
Search
9. Develop
Layout
Alternatives
10. Evaluation
Selection

11. Objective evaluation criteria Can be computerized
Algorithmic approaches provide formal procedures/steps to develop the layouts
Objective evaluation criteria
Can be computerized
Computerization: increased productivity through rapid generation of alternatives, allow for “what if” analysis

12. Characteristics of Algorithms
Data:
From-To (Flow-between), REL, Both
Objective functions:
Distanced-based From-to-chart
Adjacency-based REL chart
Do we want to maximize or minimize these objective functions?

13. The Distance Based Objective is the sum of the cost of movements between the departments.
f is the flow from dept i to j
c is the cost of moving the load (independent of MHE)
d is the distance from dept i to j

14. xij = 1 if the departments are adjacent
The Adjacency Based Objective is the sum of the flow between adjacent departments.
xij = 1 if the departments are adjacent
= 0 if the departments are not adjacent
Adjacency means that they share a border, not corners
Layouts with same adjacency score may have different travel distances

15. Relative Efficiency is computed as the normalized adjacency score.
Used to compare algorithms.
0 = < Z = < 1
May use a negative value of for X relationships

16. Discrete vs. Continuous Representation
Besides the objective function, other characteristics differentiate layout algorithms.
Discrete vs. Continuous Representation
Construction vs. Improvement Strategies
Discrete representation. It is used by most layout algorithms. The area of a department is rounded off to the nearest integer number of grids.
Note that higher number of grids increase the overall “resolution” but also increase the computational times.
2. Continuous representation. There is no underlying “grid” structure.
Although it seems more flexible than the discrete representation it is difficult to implement on a computer. These algorithms are limited to rectangular departments and rectangular buildings
Improvement Type:
Starts from an existing layout and seek to improve the objective function through “incremental” changes.
Can change the initial layout on which we want to improve
Construction Type:
Starts from “scratch”
Can be further subdivided into:
Those that assume the building dimensions are given
Those without building dimension restrictions
Are more difficult to use with existing facilities