Perancangan Tata Letak Fasilitas

(1)

Perancangan

Tata Letak Fasilitas

www.aeunike.ub.ac.id

Layout Problems

•

Design or Optimization?

Aesthetics

(2)

Aesthetics

Facility Layout Process

• Combination of art and

engineering

• Many techniques available

–Muther’s SLP Approach (1973)

(3)

Systematic Layout Planning

•

Phase I

- Determination of the location of the

area where departments are to be

laid out

•

Phase II

- Establishing the general overall

layout

•

Phase III

- Establishing detailed layout plans

•

Phase IV

- Installing the selected layout

Systematic Layout Planning

Input Data and Activities

1. Flow of materials 2. Activity Relationships

6. Space Relationship Diagram

5. Space Available 4. Space Requirements

3. Relationship Chart

8. Practical Limitations 7. Modifying Considerations

9. Develop Layout Alternatives

10. Evaluation

A

N

A

LY

ZE

S

E

A

R

C

H

S

E

L

E

C

T

Source: John S. Usher class notes

Systematic Layout Planning

• P Product: Types of products to be produced

• Q Quantity: Volume of each part type

• R Routing: Operation sequence for each part type

• S Services: Support services, locker rooms,

inspection stations, and so on

• T Timing: When are the part types to be produced?

What machines will be used during this time period?

(4)

SLP

Sample relationship diagram

1 2

4

3

5

PLANT

KANTOR

Level 0 (Overall Layout)

DIRECTOR ROOM

MEETING ROOM

INSPECTION STAFF & OPERATOR OF PRODUCTION ENGINEER, OPERATOR AND STAFF OF MAINTENANCE’S

6

SECRETARY

RECEPTIONIST

down

PRIA MARKETING MANAGER PRODUCTION MANAGER R & D MANAGER HRD MANAGER ADMINISTRATION AND FINANCE MANAGER

LOGISTICS WANITA MUSHOLLA TEMPAT WUDHU STAF MARKETING

STAF OF ADMINISTRATIO

N ANDFINANCE TEMPAT WUDHU KM ( PRIA) KM ( WANITA) 5 6 1 6 7

5 1 8 6 4

4

6

1

4 4 5 4

3 9 5 4 2,5 3 1

Lantai 2 : Office Room

Jalan Office Office Office Cutting machine x y x y x y x y x y x y x y x y x y Injection molding Grinding machine Rolling machine Welding machine Forming machine 2 Power Entry 2

2Tool Cabinet

Rak

PUNCH 25 TON

MQC

Packaging

Ruang Assembly

MQC

PPP P P P

Press machine Ruang Supply Mesin

Ruang Perkakas

MQC

Raw Material Storage Warehouse

UpElevator

FPFPFP FP FP FP

Ruang Kesehatan

Ruang Ganti Wanita Ruang Ganti Pria

L

P Toilet Pria Toilet Wanita

T. Wudhu Pria T. Wudhu Wanita

Mushollah Pria Mushollah Wanita

1.0e-2 m. x 1.0e-2 m. 1.0e-2 m. x 1.0e-2 m. 1.0e-2 m. x1.0e-2 m.

Kantin

Ruang Receptionist

Pos Satpam

Jalan Jalan

1.0e-2 m. x 1.0e-2 m. Parkir Mobil Parkir Sepeda Motor B B

A D D A A

REST AREA

Jalan Raya Rungkut Industri

18 m

24 m

4 m Receiving Area

Delivering Area 14 m

3 m 3 m 4 m 4 m 3 m 3 m 3 m 2.5 m 2.5 m 2 m 6 m 2 m

4 m 3 m 2 m 4.5 m 4.5 m 6 m 8 m 6 m Daerah Penerimaan Daerah Pengiriman PARKIR

DIRECTOR ROOM

MEETING ROOM

INSPECTION STAFF & OPERATOR OF PRODUCTION ENGINEER, OPERATOR AND

STAFF OF MAINTENANCE’S

6 SECRETARY RECEPTIONIST down PRIA MARKETING MANAGER PRODUCTION MANAGER R & D MANAGER HRD MANAGER ADMINISTRATION AND FINANCE MANAGER LOGISTICS WANITA MUSHOLLA TEMPAT WUDHU STAF MARKETING

STAF OF ADMINISTRATION

AND FINANCE TEMPAT WUDHU KM ( PRIA) KM ( WANITA) 5 6 1 6 7

5 1 8 6 4

4

6

1

4 4 5 4

3 9 5 4 2,5 3 1

Lantai 2 : Office Room

Level 1

(5)

Jalan Office Office Cutting machine x y x y x y x y x y x y x y x y x y Injection molding Grinding machine Rolling machine Welding machine Forming machine 2 Power Entry 2

2Tool Cabinet R a k

Rak

PUNCH 25 TON MQC

Packaging

Ruang Assembly MQC

PPP P

P P

Press machine Ruang Supply Mesin

Ruang Perkakas

MQC

Raw Material Storage Warehouse

UpElevator

FPFPFP

FP FP FP

Ruang Kesehatan

Ruang Ganti Wanita Ruang Ganti Pria

L P

Toilet Pria Toilet Wanita T. Wudhu Pria

T. Wudhu Wanita Mushollah Pria Mushollah Wanita

1.0e-2 m. x 1.0e-2 m.

1.0e-2 m. x 1.0e-2 m. 1.0e-2 m. x 1.0e-2 m. Kantin Ruang Receptionist Pos Satpam Jalan Jalan

1.0e-2 m. x 1.0e-2 m. Parkir Mobil Parkir Sepeda Motor B B

A D D A A

REST AREA

18 m

24 m

4 m Receiving Area Delivering Area 14 m

3 m 3 m 4 m 4 m

3 m 3 m 3 m 2.5 m 2.5 m 2 m 6 m 2 m

4 m 3 m 2 m 4.5 m 4.5 m 6 m 8 m 6 m Daerah Penerimaan Daerah Pengiriman

Level 1

Detail Layout

Level 2

Detail Layout STAF O F AD MINISTRAT IO N AND FI NANC E 7 ST A F MA R K ET IN G 6 5

Level 2

Detail Layout R ECEPT IO N IST 5 6 1 ENGI N EER , O PERA TO R AN D ST AF F OF MA INTE NA NC E’ S 6 4

Level 2

Detail Layout TEMPAT WUDHU TEMPAT WUDHU 4 4

KM PRIA KM WANITA PRIA WANITA MUSHOLLA 5 4 MEETING ROOM 6 4 0,52 STA FF & OPER A TOR OF PR O D U C TIO N 6 6

Special Considerations in Office Layout

•

Minimizing distance traveled by employees

•

Permitting flexibility so that the current layout

can be changed, expanded or downsized

easily

•

Providing a safe and pleasant atmosphere for

people to work in

•

Minimizing capital and operational costs of

the facility

Operations Review

• Is the company outgrowing available space?

• Is the available space too expensive?

• Is the current building not in the proper location?

• How will a new office layout affect the organization?

• Are office operations too centralized or

decentralized?

• Does the office structure support the strategic plan?

• Is the office layout in tune with the company's

(6)

Cubicles layout

Albany International Airport layout

Operations Review for MortAmerica, Inc.

• Is there a significant increase in mortgage lending operations of MortAmerica, Inc.?

• Are the costs of leasing and refurbishing interior space too high?

• Is there a problem with the current location? For example:

–There is not enough space for expansion

–Major attorneys’ offices, other related financial institutions and

restaurants, are not located within a reasonable distance of MortAmerica, Inc.

–Adequate parking space is not available

–Traffic is too congested

• Will a change in office location improve business?

SLP for MortAmerica, Inc.

•

Evaluation

•

Planning

•

Site selection

•

Design and layout

SLP for MortAmerica, Inc.

•

Review current space utilization

•

Determine space projections

•

Determine level of interaction between

departments

•

Identifying special consideration

Current and Future Space Requirements

Categories of Employees and Number in Each Category

Department Name Current/Future

Requirements Senior

Executive Senior Staff

Staff Clerical/Secretary Net

Space Required

Gross Space, 150% of Net Space

Current space/employee 150 100 75

Number of employees 1 4 1

Current total space/category

150 400 75 625 938

Future space/employee 120 75

Number of employees 6 1

Customer Service (CS)

Future space/category 720 75 795 1,193

400 1,000 150 1,550 2,325

Future space/employee 250 200 100 75

Number of employees 1 1 15 1

Mortgage processing/marketing (MP/M)

Future space/category 250 200 1,500 75 2,025 3,038

Current space/employee 100 75

Number of employees 10 1

1,000 75 1,075 1,613

Future space/employee 80

Number of employees 5

Credit check (CC)

Future space/category 400 400 600

Current space/employee 200 100 90 75

400 400 1,350 375 2,525 3,788

Future space/employee 250 100 100 75

Operations Audit (O/A)

Future space/category 750 400 2,000 150 3,300 4,950

Top management (TM)

1,250 400 500 2,150 3,225

(7)

Current and Future Space Requirements

Support service area Current net space

Current gross space150% of net space Future net space

Future gross space 150% of net space

Copying/Printing Area (C/P) 300 450 465 700

File Storage Room (FS) 300 450 80 120

Customer Waiting Lounge (CW) 300 450 800 1200

Conference Rooms (CR) 500 750 1000 1500

Employee Break Room (EBR) 200 300 850 1275

Rest Rooms (RR) 200 300 500 750

Total 1800 2700 3695 5545

Relationship diagram for MortAmerica, Inc.

Customer service (CS)

Mortgage processing (MP)

Credit check (CC)

Closing/underwriting (C/U)

Top Management (TM) E E I I O I E O I Operations/audit (O/A) Copying/printing (C/P)

Files storage (FS)

Customer waiting (CW)

Conference room (CR) I A U U A A O U I

Employee break room (EBR)

Rest rooms (RR) O X I I U X X I I O U A O E U U O I X U U U U O I I U I I X X U U I I U U U A U U I A U O O O A

Activity relationship diagram for

MortAmerica, Inc.

MP CS CR RR CC C/U TM CW O/A FS C/P EBR

Space relationship diagram for

MortAmerica, Inc.

MP CS CR RR CC C/U TM CW O/A FS C/P EBR

Pre-architectural layout for MortAmerica,

Inc.

TM MP CC C/U CW RR M RR W CS CR C/P FS EBR O/A

Engineering design approach

1. Identify the problem

2. Gather the required data

3. Formulate a model for the problem

4. Develop an algorithm for the model and solve it

5. Generate alternative solutions, evaluate, and select

(8)

OSHA, ADA and Local Codes

Service and Manufacturing Facilities

Organization Showers Lavatories Water Closets Water

Fountain Others

Restaurants - 1 per 200 1 per 75 1 per 500 1service

sink

Arenas (capacity more than 3000)

- 1 per 200

(male); 1

per 150

(female)

1 per 120 (male); 1 per 60 (female)

1 per 1000 1 service sink

Churches - 1 per 200 1 per 150 (male); 1

per 75 (female)

1 per 1000 1 service sink

Schools - 1 per 50 1 per 50 1 per 100 1 service

sink

Airports - 1 per 750 1 per 500 1 per 1000 1 service

sink

Factories Section

411

1 per 100 1 per 100 1 per 1000 1 service

sink

Hospitals 1 per 15 1 per room 1 per room 1 per 100 1 service

sink

Prisons 1 per 15 1 per cell 1 per cell 1 per 100 1 service

sink

Hotels 1 per

room

1 per room 1 per room - 1 service

sink

Dormitories 1 per 8 1 per 10 1 per 10 1 per 100 1 service

sink

Basic

Algorithms

for

The Layout

Problem

Introduction (1)

• A model by itself does not provide a solution to a problem, however, algorithms or solution techniques have to be developed to solve model

• An algorithm is a step-by-step procedure that finds a solution to a model, and hence to the problem, in a finite number of steps

• A number of algorithm have been proposed and these may be classified as: (a) Optimal algoritms and (b) Heuristic algorithms

• All optimal algorithms developed for the layout problem require extremly high memory and computational time, and they increase exponentially as the problem size increases.

Introduction (2)

• The heuristic algorithms are devided into tree classes:

1. Construction algorithms: starting with an

empty layout, they add one department (or a set of departments) after another until all the departments are included in the layout

2. Improvement algorithms; systematically modify

the starting solution and evaluate the resulting modified solution. If it is better, the modification is made permanent. If not, the systematic

modification is continued until it is n longer possible to produce better solutions

3. Hybrid (composite) algorithms; algorithms that

(9)

Algorithmic Approaches

 Layout algorithms can be classified according to:

 Type of input data; qualitative flow data –

quantitative flow data

 Objective functions; minimizing of the sum of

flows time distance – maximizing an adjacency score

 Format they use for layout representation;

discrete – continuous representation

 Their primary function; layout improvement –

layout construction

Construction Algorithms

• Construction algorithms generate a facility layout from scratch.

• Starting with an empty layout, they add one department (or a set a

departments) after another until all the departments are included in the layout

• Tha main difference among the various construction algorithms

relate to the criteria used to determine the:

–First department to enter the layout

–Subsequent department or departments added to the

layout

–Location of the first and subsequent departments in

the layout

• Example: Modified Spanning Tree Algorithm for Single-row Layout

Problem, Graph Theoritic Approach

Modified Spanning Tree (MST)

Step 1: Given the flow matrix [fij], clearance matrix [dij] and machine

lengths li, compute an adjacency weight matrix [f’ij] where f’ij =

(fij) (dij+0.5(li+lj))

Step 2: Find the largest element in [f’ij], and the corresponding i, j.

Denote this pair of i, j, as i*, j*. Connect machines i*, j*. Set

f’i*j* = -

Step 3: Find the largest element f’i*k, f’j*lin row i*, j* of matrix [f’ij]. If

f’i*k≥ f’j*l, connect k to i*, remove row i*, column i* from

matrix [fij] and set i*=k. otherwise, connect l to j*, remove row

j*, column j* from matrix [f’ij] and set j*=l. Set f’i*j* = f’j*i* = -

Step 4: Repeat step 3 until all machine are connected. The sequence of machines obtained determines the arragement of machines

Modified Spanning Tree (MST)

2-Opt Algorithm

• Consider multirow layout problem in which the departments are all squeres with equal area. • Assume that the number of departments in every row

and column is equal to m and n

• The number of location in which the departments will be located is also equl to mn and is known

• 2-Opt algorithm is used to solve the same model (QAP or ABSModel 2) heuristically

. . . mn

. . . .

(10)

2-Opt Algorithm

Step 1: Let S be the initial solution provided by the user and z its OFV. Set i=1; j=i+1=2

Step 2: Consider the exchange between the position of department i and j in the solution S. If the exchange

results in a solution S’ that has an OFV z’<z, set z=z’ and S=S’. If j<mn, set j=j+1; otherwise, set

i=i+1, j=i+1. If i<mn, repeat step 2; otherwise, go to step 3

Step 3: If set S=S*, z=z*, i=1, j=i+1=2 and go to step 2. Otherwise, return S* as the best solution to the user. Stop

2-Opt Algorithm

2(1) 1(2) 1(2)

3-Opt Algorithm

• The 3-Opt algorithm is similar to the 2-Opt algorithm except that is considers exchanging the position of three departments at a time.

• If the layout problem with mn departments, 2-Opt consider mn(mn-1)/2 pairwise exchange for each layout and 3-Opt considers (mn)!/[(mn-3)!3!] exchange. • Because we are searching and evaluating more layouts in

3-Opt than in 2-Opt, 3-Opt should yield better results, but it also takes significantly more computation time

3-Opt Algorithm

Step 1: Let S be the initial solution provided by the user and z its OFV. Set S*=S, z*=z, i=1; j=i+1; k=j+1 Step 2: Consider changing the position of department i to

that of j, j to that of k, and k to that of i,

simultaneously. If the resulting solution S’ has OFV z’<z, set z*=z’ and S*=S’.

Step 3: If k<mn, set k=k+1, and repeat step 2. Otherwise, set j=j+1 and check if j<mn-1.

If j<mn-1, set k=j+1, and repeat step 2. Otherwise, set i=i+1, j=i+1, k=j+1, and check if i<mn-2. If i<mn-2, repeat step 2. Otherwise, go to step 4 Step 4: If set S=S*, z=z*, i=1, j=i+k, k=j+1 and go to step

2. Otherwise, return S* as the best solution to the user. Stop

Modified Penalty Algorithm

• MP algorithm involve transforming the contrained ABSModels into an unconstrained one using the penalty method.

• The square of each constraint is multiplied by a penalty parameter and placed in the objective function

0 , , , Subject to 3 22 21 3 3 3 32 32 31 31 2 2 2 22 22 21 21 1 1 1 12 12 11 11 3 3 12 12 11 11                 n n n n n n n n n x x x b x a x a x a b x a x a x a b x a x a x a x c x c x c Minimize     

Modified Penalty Algorithm

• The constrained model is transformed into an unconstrained model using penalty parameters 1, 2

dan 3





















2

(11)

Modified Penalty Algorithm

Step 0: Obtain values for from the user. Set S=initial solution vector and z=corresponding OFV

Step 1: Transform the constrained model into an unconstrained one

Step 2: Solve the unconstrained minimization model using the Powel algorithm. If the OFV of the resulting solution is less than or equal to z, set S*=new solution vector and z*=OFV corresponding to S*

Step 3: Modify solution vector S* so that a feasible solution obained

Step 4: Improve the solution using greedy 2-Opt. Stop

Pairwise Exchange Method (1)

 It is an improvement-type layout algorithm

 Its implementation with unequal-area departments will be shown later via CRAFT, MULTIPLE

 Example: Consider 4 department of equal size. The existing layout is shown

1

2

3

4

Pairwise Exchange Method (2)

To

From 1 2 3 4

1 10 15 20

2 10 5

3 5

4

The objective function value for the existing layout:

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

Pairwise Exchange Method (3)

Since all departments areas are assumed to be of equal size, the feasible exchanges of iteration 1 are 1-2, 1-3, 1-4, 2-3, 2-4, and 3-4

Select the pair 1-3 and perform the exchange in the layout

TC₂₁₃₄=10(1) + 15(1) + 20(2) + 10(2) + 5(3) + 5(1) = 105

TC₃₂₁₄=10(1) + 15(2) + 20(1) + 10(1) + 5(2) + 5(3) = 95

TC₄₂₃₁=10(2) + 15(1) + 20(3) + 10(1) + 5(1) + 5(2) = 120

TC₁₃₂₄=10(2) + 15(1) + 20(3) + 10(1) + 5(1) + 5(2) = 120

TC₁₄₃₂=10(3) + 15(2) + 20(2) + 10(1) + 5(2) + 5(1) = 105

TC₁₂₄₃=10(1) + 15(3) + 20(2) + 10(2) + 5(1) + 5(1) = 125

For the next iteration, we consider all feasible exchange which consist of the same set as in iteration 1

The pair 2-3 is selected with a total cost value of 90.

TC₃₁₂₄=10(1) + 15(1) + 20(2) + 10(1) + 5(1) + 5(3) = 95

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

TC3241=10(2) + 15(1) + 20(3) + 10(1) + 5(1) + 5(2) = 120

TC₁₃₂₄=10(2) + 15(3) + 20(1) + 10(1) + 5(1) + 5(2) = 110

TC₂₃₁₄=10(2) + 15(1) + 20(1) + 10(1) + 5(3) + 5(2) = 90

TC3412=10(1) + 15(2) + 20(1) + 10(3) + 5(2) + 5(2) = 105

TC4213=10(1) + 15(1) + 20(1) + 10(2) + 5(1) + 5(2) = 105

Pairwise Exchange Method (5)

Since the lowest total cost is 95, which worse than the total cost value of 90 in the second iteration, the procedure terminated. The final layout arrangement is 2-3-1-4

TC₃₂₁₄=10(1) + 15(2) + 20(1) + 10(1) + 5(2) + 5(3) = 95

TC₁₃₂₄=10(2) + 15(1) + 20(3) + 10(1) + 5(1) + 5(2) = 120

TC₃₄₂₁=10(1) + 15(3) + 20(2) + 10(2) + 5(1) + 5(1) = 125

TC₂₁₃₄=10(1) + 15(1) + 20(2) + 10(2) + 5(3) + 5(1) = 105

TC₃₁₄₂=10(2) + 15(1) + 20(1) + 10(3) + 5(1) + 5(2) = 100

(12)

 The pairwise exchange procedure is not guaranted to yield the optimal layout solution because the final outcome is dependent on the initial layout, that is, a different initial layout can result in another solution (local optimality)

 It may have observed that it is possible to cycle back to one of the alternative layout arrangements from a previous iteration

 It can be easily accomplished only if the pair of departments considered are of equal size

Graph-based Method (1)

 The graph-based method is a construction-type layout algorithm (its root graph theory)

 It is often used with an adjacency-based objective

 To find a maximally weighted block layout is equivalent to obtaining an adjacency graph with the maximum sum of arc weights

Graph-based Method (2)

Graph-based Method (3)

Procedure

Step 1 : Select department pair with the largest weight.

Ties, if any, are broken arbitrarily

Step 2 : Select the third department to enter. The third

department is selected based on the sum of the weights with respect to selected departments in Step 1

Step 3 : Pick the fourth department to enter by

evaluating the value of adding one of the unassigned departments represented by a node on a face of the graph. A face of a graph is a bounded region of a graph

Graph-based Method (4)

Step 4 : The remaining task is to determine on which

face to insert the remaining department. The optimal solution can be found with a minimum total sum of arch weights

Step 5 : Having determined an adjacency graph, the

final step is to construct a corresponding block layout. A block layout based on the final adjacency graph is made. The manner by which we constructed the block layout is analogous to the SLP method. We should note that in constructing the block layout, the original department shapes had to be altered

significantly in order to satisfy the requirements of the adjacency graph

(13)

Graph-based

Method (6)

Graph-based Method (7)

CRAFT

 Computerized Relative Allocation of Facilities

Technique (Armour, Buffa, and Vollman, 1963)

 Input data : from – to chart

 An improvement-type layout algorithm

 Departments represented in a discrete fashion

 It begins by determining the centroids of the departments in the initial layout, then calculates the rectilinear distance between pairs of department centroids and stores values in a distance matrix

 CRAFT next considers all-possible two-way (pairwise) or three-way department exchanges and identifies the best exchange ( maximal reduction in layout cost)

CRAFT

 The next iteration starts with CRAFT once again identifying the best exchange by considering all-possible two-way or three-way exchanges in the (update) layout.

 The process continuous until no further reduction in layout cost can be obtained

 The final layout obtained in such a manner is also known as a two-opt (three-opt) layout

CRAFT

Initial CRAFT Layout

(z = 2974 x 20 = 59,480 units)

Intermidiate CRAFT Layout

(14)

BLOCPLAN

 Departments arranged in bands which the number of bands is determined by the program and limited to two or three bands

 All the departments are rectangular in shape

 Input data: a relationship chart anda a from-to chart, the two charts can be used only one at a time when evaluating a layout

 Layout cost can be measured either by the distance-based objective or the adjacency-based objective

 BLOCPLAN uses the continuous representation

 BLOCPLAN may be used both as a construction algorithm and an improvement algorithm

LOGIC

 Layout Optimization with Guillotine Induced Cuts

(Tam, 1991)

 Input data: a from-to chart

 The layout is represented in a continuous fashion

 A construction and improvement algorithm

 LOGIC is based on dividing the building into smaller and smaller portions by executing

successive “guillotine” cuts (straight lines that run

from one end of the building to the other). Each cut is either a vertical cut or a horizontal cut

LOGIC

(15)

MULTIPLE

 MULTI-floor Plant Layout Evaluation (Bozer,

Meller, and Erlebacher, 1994) is similar to CRAFT

 Input data: a from-to chart

 It was originally develop for multiple-floor facilities (It can also be used in single-floor facilities)

 The layout is represented in a discrete fashion

 An improvement-type layout algorithm

 MULTIPLE’s use of “spacefilling curves” (SFC)

for exchange any two departments whether they are adjacent or not

MULTIPLE

Suppose the following area values are given for six departments: A₁=16, A2=8, A3=4, A4=16, A5=8, and A6=12

REFERENCES

•

Heragu, S. (2008).

Facilities Design

(3rd Ed.).

CRC Press.