Facility Layout Introduction Basic Concepts and Definitions What

Facility Layout Introduction Basic Concepts and Definitions

What defines a good layout? Right equipment Right method Right place Effective processing Shortest distance Shortest time

Production systems correlate to the necessary type of layout. High Production Volume Product Layout Group Technology Layout Medium Fixed Location Layout Process Layout Low Medium Product Variety High

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

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

Stores Milling Turning Press Plate Assembly Warehouse From – To Chart Stores – 12 6 9 1 4 – Milling – – 7 2 – Turning – 3 – – 4 – – Press – – 3 1 1 Plate – 3 1 – – 4 3 Assembly 1 – – – 7 Warehouse – – – –

Relationship (REL) Chart Code 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 O 5 A 4 I 4 U 6 I 4 I 1 U 6 I 4 O 5 A 4 O 5 U 3 O O 2 5 U O 6 5 O O 5 5 O E 5 4 U 3 U 6 E 4 O 4 U 3 I 4 U 3 O 5 Reason 1 Frequency of use high 2 Frequency of use medium 3 Frequency of use low 4 Information flow high 5 Information flow medium 6 Information flow U 6 Rating Definition A Absolutely Necessary E Especially Important I Important O Ordinary Closeness OK U Unimportant X Undesirable

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. 306 -309)

Algorithmic approaches provide formal procedures/steps to develop the layouts • Objective evaluation criteria • Can be computerized

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

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

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

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

Besides the objective function, other characteristics differentiate layout algorithms. • Discrete vs. Continuous Representation • Construction vs. Improvement Strategies