1. Facilities Planning and Design Course code: 1704031511
Spring
Required Text: Tompkins et al., (2003). Facilities Planning, 3rd or later Edition, John Wiley and Sons Inc.
Students are encouraged to refer to the text book, and to take notes during the lectures.

2. Chapter 6 – Layout Planning Models and Design Algorithms
Major Topics:
Block layout vs detailed layout
Decisions affecting space requirements and layouts
Basic layout types
Layout procedures: construction and improvement
Algorithmic approaches
Finalizing layout alternatives

3. Block layout vs detailed layout
Shows relative locations and sizes of the departments
Detailed layout:
Shows the exact locations of all equipment, work benches, storage areas within each department
Decisions affecting space requirements and layouts
Centralized vs decentralized storage of WIP, tooling and supplies
Fixed path vs variable path handling
Unit load size
Degree of automation used in handling
Type of inventory and material control

4. Basic layout types Manufacturing Layouts: Depending on product
volume-variety, facility
layout can be classified as:
Product Layout (Flow Shop)
Product Family (group technology) Layout
Process Layout (Job Shop)
Fixed Location (Static) Layout
Specialized Layouts:
Warehouses
Offices
Large shopping centers

5. Layout procedures: construction and improvement
Construction-type layout method: involves developing a new layout from scratch.
Improvement-type method: generates layout alternatives based on an existing layout.
Layout and material handling system should be designed simultaneously (construction-type).
If existing layout is to be revised, the effectiveness of material handling system should be reviewed as well (improvement-type).

6. Procedures for plant layouts
Apple’s plant layout procedure (20 steps)
Reed’s plant layout procedure (10 steps) and the most important step is preparing the layout planning chart which includes:
Flow process (O- T - S - I)
Standard time for each operation
Machine selection and balance
Manpower selection and balance
Material handling requirements
Muther’s Systematic Layout Planning (SLP) procedure

7. Reed’s plant layout procedure - Layout planning chart

8. Muther’s Systematic Layout Planning (SLP) procedure

9. Relationship Diagram
Muther’s Systematic Layout Planning (SLP) procedure

10. Space Relationship Diagram
Muther’s Systematic Layout Planning (SLP) procedure

11. Develop layout alternatives
Muther’s Systematic Layout Planning (SLP) procedure

12. Algorithmic approaches
Algorithm approaches are based on relative placement of departments on the basis of:
their “closeness ratings” – Relationship chart, qualitative data
“material flow intensities” – From-to chart, quantitative data
Both input forms can be converted to one another.
Algorithms used to solve the layout problem:
Pairwise exchange method
Graph-based method
CRAFT-Computerized Relative Allocation of Facilities Technique
Mixed integer Programming (MIP)
Simulated Annealing (SA) and Genetic Algorithms (GA)

13. Algorithmic approaches
Minimize the total cost of movements between departments
Maximize the total relationship
Normalized Adjacency score
Normalized Adjacency score with positive and negative flows

14. Discrete vs. continuous layout representation
Discrete vs. continuous layout representation

15. Examples of split and unsplit departments

16. Pairwise exchange method
Procedure
Calculate total cost for the existing layout
For each iteration evaluate all feasible exchanges in the locations of department pairs
Select the pair that results in the largest reduction in total cost
Recompute the distance matrix each time an exchange is performed
If the lowest total cost for your next iteration is worse than the total cost for the previous iteration, the procedure is terminated
The method does not always guarantee yielding the optimal solution, only local optimum
Final solution depends on the starting solution
The procedure may cycle back to a previous alternative
Symmetric layout may occur
Pairwise exchange can be easily accomplished only if the departments are of the same size
Easy to implement if department areas are the same

17. Pairwise exchange method
Flow matrix
Distance matrix
Assume Cij = 1 for all i, j
Iteration 0, z = 125
Iteration 1, z = 95
Iteration 2, z = 90
Flow matrix remains the same, distance matrix changes

18. Graph-based method Procedure
Nodes represent departments,
arcs represent relationship weights
(flow) between departments
Procedure
1.Select the department pair with the largest weight. Ties are broken arbitrarily
2.Select the third department to enter based on the largest sum of the weights with the first two departments
3.Pick the fourth department to enter on a face of the graph (a bounded region of a graph)
4.Determine an adjacency graph
5.Construct a corresponding block layout

19. Graph-based method
Step 1

20. Graph-based method
Step 2-3-4

21. Graph-based method
Block layout generated from graph of step 4

23. CRAFT Input is From-To chart Department shapes are
not restricted to rectangular ones or similar area

24. Initial CRAFT layout (z = 59,480)
CRAFT Procedure
1.Determine department centroids.
2.Calculate rectilinear distance between centroids.
3.Calculate transportation cost for the layout.
4.Consider department exchanges of either equal area departments or departments sharing a common border.
5.Determine the estimated change in transportation cost of each possible exchange.
6.Select and implement the departmental exchange that offers the greatest reduction in transportation cost.
7. Repeat the procedure for the new layout until no interchange is able to reduce the transportation cost.
Initial CRAFT layout (z = 59,480)

25. Intermediate CRAFT layout (z = 59,060) Final CRAFT layout (z = 56,670)

26. Finalizing layout alternatives
(Massaging)