layout.ppt

LAYOUT

Chapter 6

Dr. Muzaffer Kapanoglu-Copyright 2005

Fixed product layoutAdvantages Limitations

Reduced material moves Highly flexible Job enrichment Promotes pride & quality Responsibility

Personel-equipment moves Equipment duplicates Greater skill Close control& coordination Increased space & greater

work-in-process


Product LayoutAdvantages Limitations

Smooth, simple, direct flow Small work-in-process inv. Short production time/unit Reduced material handling Less skill Easy production control

Line stoppage Product design changes Slowest station paces the line General supervision High equipment investment


Group LayoutAdvantages Limitations

By grouping, higher machine utilizations

Smoother flow lines and shorter travel distances

Team spirit and job enlargement

Greater labor skills for team Balancing individual cells Unbalanced flow may result

in work-in-process


Process LayoutAdvantages Limitations

Increased machine utilization General purpose equipment Highly flexible Diversity of tasks

Increased material handling Complicated production

control Increased work-in-process Longer production lines Higher skills required


Apple’s plant layout procedure1. Procure the basic data.2. Analyze the basic data.3. Design the productive process.4. Plan the material flow pattern.5. Consider the general material handling plan.6. Calculate equipment requirements.7. Plan individual workstations.8. Select specific material handling equipment.9. Coordinate groups of related operations.10. Design activity interrelationships.11. Determine storage requirements.12. Plan service and auxiliary activities.13. Determine space requirements.14. Allocate activities to total space.15. Consider building types.16. Construct master layout.17. Evaluate, adjust, and check the layout with the appropriate persons.18. Obtain approvals.19. Install the layout.20. Follow up on implementation of the layout.


Reed's Plant Layout Procedure1. Analyze the product or products to be produced.2. Determine the process required to manufacture the product.3. Prepare layout planning charts.

1. Flow process, including operations, transportation, storage, and inspections.

2. Standard times for each operation.3. Machine selection and balance.4. Manpower selection and balance.5. Material handling requirements.

4. Determine workstations.5. Analyze storage area requirements.6. Establish minimum aisle widths.7. Establish office requirements.8. Consider personnel facilities and services.9. Survey plant services.10. Provide for future expansion.


Muther's Systematic Layout Planning (SLP) Procedure

1. Flow of materials2. Activity relationships3. Relationship diagram4. Space requirements&Space available5. Space relationship diagram6. Modifying considerations7. Practical limitations8. Develop layout alternatives9. Evaluation


ACTIVITY

RELATIONSHIP

CHART


Relationship diagram


Space relationship diagram


Alternative Block Layout-1


Alternative Block Layout-2


Facility Layout Objectives (efficiency):

Layout improvement

versus

Layout construction

QAP???


Problems

6.12 Suppose five departments labeled A through E are located as shown in the layout below. Given the corresponding flow-between chart, compute the efficiency rating for the layout.

A B

C

D E

A B C D E

A — 5 0 4 -3

B — 6 -1 2

C — -6 0

D — 3

E —


Relationship Diagramming for New Layouts-1

Code Function Area(sqft) No.of unit area templates

1 Receiving 12000 6

2 Milling 8000 4

3 Press 6000 3

4 Screw M. 12000 6

5 Assembly 8000 4

6 Plating 12000 6

7 Shipping 12000 6



1. Select the first department to enter layout (using diagramming worksheet)

2. Select the second dept. to enter the layout.

3. Select the third department to enter the layout

4. Select the fourth department to enter the layout

5. Place dept. n similar to 3rd and 4th steps.



1 1 1

4 4 1 1

4 4 3 1

4 2 3 3

4 2 2 2

5 6 6 6

5 6 6 6

5 7 7 7

5 7 7 7


Pairwise Exchange Method for Layout Improvement-1A heuristic method

TC1234 = 10(1) + 15(2) + 20(3) + 10(1) + 5(2) + 5(1) = 125

ToFrom

1 2 3 4

1 - 10 15 20

2 - 10 5

3 - 5

4 -

Material Flow MatrixDistance Matrix Based on Existing Layout

ToFrom

1 2 3 4

1 - 1 2 3

2 - 1 2

3 - 1

4 -


Pairwise Exchange Method for Layout Improvements-2

FIRST ITERATION(based on the existing solution:1-2-3-4) TC2134(1-2)=10(1)+15(1)+20(2)+10(2)+5(3)+5(1)=105 TC3214(1-3)=10(1)+15(2)+20(1)+10(1) +5(2)+5(3)=95 TC4231(1-4)=10(2)+15(1)+20(3)+10(1) +5(1)+5(2)=120 TC1324(2-3)=10(2)+15(1)+20(3)+10(1) +5(1)+5(2)=120 TC1432(2-4)=10(3)+15(2)+20(1)+10(1) +5(2)+5(1)=105 TC1243(3-4)=10(1)+15(3)+20(2)+10(2)+5(1)+5(1)=125

New layout: 3-2-1-4



SECOND ITERATION (based on the previous layout: 3-2-1-4) TC3124(1-2)=10(1)+15(1)+20(2)+10(1)+5(1)+5(3)=95 TC1234(1-3)=10(1)+15(2)+20(3)+10(1)+5(2)+5(1)=125 TC3241(1-4)=10(2)+15(3)+20(1)+10(1)+5(1)+5(2)=110 TC2314(2-3)=10(2)+15(1)+20(1)+10(1)+5(3)+5(2)=90 TC3412(2-4)=10(1)+15(2)+20(1)+10(3)+5(2)+5(2)=105 TC4213(3-4) =10(1)+15(1)+20(2)+10(2)+ 5(1)+5(3)=105

New Layout: 2-3-1-4



THIRD ITERATION (based on the previous layout:2-3-1-4) TC3214(1-2)=10(1)+15(2)+20(1)+10(1)+5(2)+5(3)=95 TC1324(1-3)=10(2)+15(1)+20(3)+10(1)+5(1)+5(2)=120 TC3421(1-4)=10(1)+15(3)+20(2)+10(2)+5(1)+5(1)=125 TC2134(2-3) =10(1)+15(1)+20(2)+10(2)+5(3)+5(1)=105 TC3142(2-4) =10(2)+15(1)+20(1)+10(3)+5(1)+5(2)=100 TC4123(3-4) =10(1)+15(2)+20(1)+10(1)+5(2)+5(3)=95

Since the possible changes resulted in increase then the previous layout is the best. Therefore the best is:

2-3-1-4 Local best Global best: 90 (1-2;2-4;3-3;4-1) (By using QAP in Lingo)


Graph-based construction method for new layouts

Total Weight:63 Total Weight: 71

Adjacency graphs for alternative block layouts

Rel-chart


Graph-based construction methods for new layouts

STEPS (node insertion algorithm in building adjacency graph):

1. Select the department pair with the largest weight.2. Select the other depts consecutively based on the

sum of the weights with respect to the depts already selected.

3. Place the selected dept on one of the faces of the graph)

4. Build the block layout based on the final adjancency graph.


Graph-based construction method for new layout

Example


Mixed Integer Programming in continuous facility layout problems


CRAFT (Computerized Relative Allocation of Facilities Technique)

1963-Armour, Buffa, Vollman Improvement-type algorithm

Initial solution Rectilinear distances between department

centroids CostxDistances All-possible two-way and three-way department

exchanges Determine the best exchange (that yields the

best reduction in the layout cost)


CRAFT

Updates the layout according to the best exchange-calculates layout efficiency

Exchanges departments that either adjacent or equal in area.

If the area is not equal, the algorithm may result in split department.


6.24Consider four departments labeled A, B, C, and D. Each department is represented by a 1X1 square. The following data are given:

Location of department A is fixed. Answer the following questions using CRAFT with two-way exchanges only.

a. List all the department pairs that CRAFT would consider exchanging. (Do not compute their associated cost.)

b. Compute the actual cost of exchanging departments C and D.c. Given that department A is fixed and that each department

must remain as a 1 X 1 square, is the layout obtained by exchanging departments C and D optimum? Why or why not? (Hint: examine the properties of the resulting layout and consider the objective function of CRAFT.)


6.25 The following layout is an illegal CRAFT layout. Nevertheless, given that the volume of flow from A to B is 4, A to C is 3, and B to C is 9, and that all move costs are 1, what is the layout cost?


6.26 (Revised) When CRAFT evaluates the exchange of departments, instead of actually exchanging the departments, it only exchanges the centroids of departments.

a. What is the impact of this method of exchanging if all departments are the same size?

b. Given the following from-to-chart and scaled layout (each square is 1 X 1), what does the evaluation of the exchange of departments B and C indicate should be saved over the existing layout and what is actually saved once this exchange is made?

To

From A B C

A — 10 6

B 2 — 7

C 0 0 —

BBBBCAAA

BBBBCAAA

BBBBCAAA

B

B

B


6.27 Explain the steps CRAFT would take with the following problem and determine the final layout. Only two-way exchanges are to be considered. (Use CRAFT DSS.)

ToFrom A B C D E

A — 3 2 1 0

B 0 — 1 3 0

C 1 0 — 4 0

D 0 0 0 — 0

E 0 0 0 0 —

From-to chart

A A AA A AA A A

B B B

C C CC C C

DDDDDD

E E E E E E

Initial Layout


A Continuous Algorithm: BLOCPLAN

BLOCPLAN 2 or 3 bands Building length Construction or improvement


A Continuous Algorithm: LOGIC

LOGIC Vertical or Horizontal cuts Construction or improvement Example


Another discrete algorithm: MULTIPLE (1)

MULTI-floor Plant Layout Evaluation Developed by Bozer, Meller, and Erlebacher Initially multi-floor facilities but can also be used for

single floor facilities Similar to CRAFT Uses a From-To (or Flow-Between) Chart Departments are not restricted to rectangular shapes Like Craft, improvement-type layout algorithm Two-way exchanges are sought Exchange with the largest reduction is selected Steepest-descent procedure


Multiple (2)

Can exchange any two departments Use spacefilling curves (SFCs) Reconstruct a new layout when any two departments are

exchanged Also known as Hilbert curve

Connects each grid such that always an adjacent grid is visited.

Each grid is visited only once.


Multiple: Building Hilbert curve (3)(Fill Sequence: 1-2-3-4-5-6)

Dept Area

1 16

2 8

3 4

4 16

5 8

6 12


Multiple: Building Hilbert curve (4)(Fill sequence: 5-2-3-4-1-6 following the exchange 1 and 5)

Dept Area

5 8

2 8

3 4

4 16

1 16

6 12

layout.ppt

Documents

layout planning charts

construct master layout

material handling requirements

equipment requirements

storage requirements

flow process

material flow pattern

relationship diagramming