CRAFT

1Facility Design-Week 9Computerized Layout PlanningBy Anastasia L. Maukar1Created by Lorna StJohnFor Operations Management 345Professor Tom FosterWednesday, May 08, 20022Computerized Layout PlanningFocus on how computers can aid the facility layout process.

Designer must interact with multiple design databases and provide the integration between them to translate information and ensure consistency.

23Computerized Layout PlanningConcentrate on decision aids for block layout planning.Information requiredCommon elementsClassical layout programsCraft, Corelap, Aldep, and PlanetNewer layout programsM-Craft, LayOpt, FactoryPlan34Computerized Layout PlanningInformation in layout planningNumeric informationSpace required for an activityTotal flow between two activitiesLogic information Preferences of the designer, i.e., activity relationship chartGraphical informationDrawing of the block plan4Numeric and logic information is relatively easy to manipulate. The largest difficulty is obtaining the logic information in the first place.The graphical information poses the largest challenge.5Computerized Layout PlanningKey element of computerized layout planning is the representation and manipulation of these three types of information.Graphical representation is most challenging. A method suitable for display is not suitable for manipulation and vice-versa.5Numeric and logic information is relatively easy to manipulate. The largest difficulty is obtaining the logic information in the first place.The graphical information poses the largest challenge.6Computerized Layout TechComputerized Layout TechniqueA Layout Construction Procedure: ALDEP, CORELAPA Layout Improvement Procedure, CRAFTDistance Between Two DepartmentsTotal Distance TraveledSavings and a Sample ComputationImprovement ProcedureExact Centroids

67Suppose that we are given some space for some departments. How shall we arrange the departments within the given space? We shall assume that the given space is rectangular shaped and every department is either rectangular shaped or composed of rectangular pieces.We shall discuss a layout improvement procedure, CRAFT, that attempts to find a better layout by pair-wise interchanges when a layout is given anda layout construction procedure, ALDEP/CORELAP, that constructs a layout when there is no layout given.Computerized Layout Technique78ALDEPAutomated Layout Design Program ALDEP is a construction procedure.ALDEP does not need any initial layout. ALDEP constructs a layout when there is none. Given Size of the facility The departmentsSize of the departmentsProximity relationships (activity relationship chart) andA sweep width (defined later)9ALDEPUse: vertical scanning pattern2 disadvantages: scoring method and the fixed values assigned to the closeness ratings.The size of the facility and the size of the departments are expressed in terms of blocks.Score is determined using the numerical values assigned to the closeness rating). A = 43 = 64 I = 41 = 4U = 0E = 42 = 16O = 40 = 1X = 45 = 1.024

10ALDEPA: absolutely necessaryE: especially important I: importantO: ordinarily importantU: unimportantX: undesirableProduction areaOffice roomsStorageDock areaLocker roomTool roomAAA OOUOO UU U UEX IFigure 1. ARC11ALDEP The procedure will be explained with an example. Suppose that the facility is 8 blocks (horizontal) 6 block (vertical).

The departments and the required number of blocks are:Production area (P) 14 blocksOffice rooms (O) 10Storage area (S)8Dock area (D)8Locker room (L)4Tool room (T)4

12ALDEPThe proximity relationships are shown as figure 1.ALDEP starts to allocate the departments from the upper left corner of the facility. The first department is chosen at random. By starting with a different department, ALDEP can find a different layout for the same problem. 13ALDEPLets start with dock rooms (D). On the upper left corner 8 blocks must be allocated for the dock area.The sweep width defines the width in number of blocks. Let sweep width = 2. Then, dock area will be allocated 2 4 = 8 blocks.

14ALDEPTo find the next department to allocate, find the department that has the highest proximity rating with the dock area (D). Storage area (S) has the highest proximity rating A with the dock area.So, the storage area will be allocated next. The storage area also needs 8 blocks.15ALDEPThere are only 2 2 = 4 blocks, remaining below dock area (D). After allocating 4 blocks, the down wall is hit after which further allocation will be made on the adjacent 2 (=sweep width) columns and moving upwards.

16ALDEPSee carefully that the allocation started from the upper left corner and started to move downward with an width of 2 (=sweep width) blocks.After the down wall is hit, the allocation continues on the adjacent 2 (=sweep width) columns on the right side and starts moving up.This zig-zag pattern will continue.Next time, when the top wall will be hit, the allocation will continue on the adjacent 2 (=sweep width) columns on the right side and starts moving down. 17ALDEPTo find the next department to allocate, find the department that has the highest proximity rating with storage area. Production area (P) has the highest proximity rating A with the storage area. The production area (P) needs 14 blocks. After allocating 8 blocks, the top wall is hit and the remaining 6 blocks are allocated on the adjacent 2 (=sweep width) columns moving downward.

18ALDEPTo find the next department to allocate, find the department that has the highest proximity rating with production area.Tool room (T) has the highest proximity rating A with the production area. The tool room needs 4 blocks. Next, there is a tie, both locker room (L) and office room (O) has the same proximity rating of U with the tool room.Ties are broken at random. So, any of the locker room or the office room can be allocated next.

19ALDEPLets choose locker room (L) room at random. Then, the last department must be office room (O). The resulting layout is shown below.Note that since the ALDEP chooses the first department at random and since the ties are broken at random, ALDEP can give many solutions to the same problem. Using the layout, the adjacency relationships and the proximity ratings, we can find an overall rating of each layout. Then, the layout with the highest overall rating is selected.

20ALDEPAfter a layout is obtained, a score for the layout is computed with the following conversion of proximity relationships:A = 43 = 64, E = 42 = 16I = 41 = 4, O= 40 = 1U= 0,X = -45= -1024If two departments are adjacent in the layout then the weight corresponding to the rating between the two departments is added to the score. 21ALDEPLets compute the overall rating of the layout constructed. Make a list every pair of adjacent departments. For each pair, a letter rating will be obtained from the activity relationship chart (see figure 1)Convert the score into a numeric score using the conversion scheme on the previous slide.22ALDEP

Adjacent departments:(D,S)(D,P)(S,P)(S,T)(S,L)(P,T)(P,O)(T,L)(T,O)(L,O)23ALDEPAdjacents DeptProximity RatingsValueScore(D,S)A64128(D,P)I48(S,P)A64128(S,T)O12(S,L)U00(P,T)A64128(P,O)O12(T,L)U00(T,O)U00(L,O)X-1024-2048-763-152624The process is repeated several times and the layout with the highest score is chosen. Notice the large negative weight associated with X ratings. If the departments which cannot be next to each other, are adjacent in a layout, then the layout score reduces significantly. This is important because ALDEP also uses a cut-off score (if not specified by the user this cut-off is zero) to eliminate any layout which has a layout score less than the cut-off score.ALDEP25CORELAPUses Relationship Chart as input (REL)

Requires users to assign weights to the alphabetic ratings in the REL chart . (Closeness Ratings)

Computes the total closeness ratings (TCR) for each department by summing all the CR associated with that department.

Values selected for ratings are important

CORELAPImportance of ClosenessValueAEIOUXClosenessLinecodeNumericalweightsAbsolutely necessaryEspecially importantImportantOrdinary closeness OKUnimportantUndesirable3226842-3227CORELAP - STEPSSelection Procedure

Placement and Evaluation Procedure

28CORELAP STEP 1First department: Where:

Second department: X-relation last placed departmentA-relation with first. If none E-relation with first, etcetera

29CORELAP Tie Breaker RulesHighest TCR Largest Area Lowest Dept. Number (random)30CORELAP STEP 2Department areas are converted into grid squares.CORELAP does not take the building shape into account. The final shape of the facility created by CORELAP depends on the placement of departments it has selected.

31CORELAP STEP 2Place the first department in the center of the layoutSubsequent department is placed abutting already placed departments in the position that gives the best placement ratingAfter the layout is completed CORELAP calculates a numerical score for the layout

32CORELAP STEP 21st812376542nd33Example of Dept Placements2413(b)6502413(c)85024133423233(a)800Contoh: Dept. 1, 2, 3 sudah diletakkan di layout dan dept. 4 akan diletakkan. Weighted Rating: (assigned by the user)A = 600 E = 200 I = 50 O = 10 U = 0 X = 200

1 - 4: A2 4: E3 4: I

34Procedure to Place DepartmentsAssume that a department is placed in the middle (position 0). Then, if another department is placed in position 1, 3, 5 or 7, it is fully adjacent with the first one. It is placed in position 2, 4, 6 or 8, it is partially adjacent. 8765432108761Pusat523435Procedure to Place Departments876543210For each position, Weighted Placement (WP) is the sum of the numerical values for all pairs of adjacent departments.The placement of departments is based on the following steps:1. The first department selected is placed in the middle.2. The placement of a department is determined by evaluating all possible locations around the current layout in counterclockwise order beginning at the western edge.3. The new department is located based on the greatest WP value.

36Example - CORELAPCV values:V(A) = 125V(E) = 25V(I) = 5V(O) = 1V(U) = 0V(X) = -125

Partial adjacency: = 0.51. Receiving2. Shipping3. Raw Materials Storage4. Finished Goods Storage5. Manufacturing6. Work-In-Process Storage7. Assembly8. Offices9. Maintenance A A E O U U A O E E E A A X X A U U A O O A O A O U E A U E U E A U O A1. Receiving2. Shipping3. Raw Materials Storage4. Finished Goods Storage5. Manufacturing6. Work-In-Process Storage7. Assembly8. Offices9. Maintenance37Table of TCR Values

38Example (cont.)712512512512562.562.562.562.5712562.562.562.5187.5512562.5187.5187.5187.57062.505187.5187.59187.562.512562.5062.512570125.5051.59126.50.510.50163.5312562.562.539Example (cont.)71255137.59250100337.537.512.5112.512.562.562.5137.537.53171255912512.587.5137.512.562.512562.50025412562.57591125310111.512518841.50.5210.50.563.562.562.540Example (cont.)75975-60.53112.5187.5-62.5-1124-37.512.522512.512.5-37.5-61.525.5612.50.510.50.5759314268Dept.DepartmentSummaryTCROrder

1 2 3 4 5 6 7 8 9 A E I O U X

1

2

3

4

5

6

7

8

9 - A A E O U U A O

A - E A U O U E A

A E - E A U U E A

E A E - E O A E U

U O A E - A A O A

U O U O A - A O O

U U U A A A - X A

A E E E O O X - X

O U A U A O A X - 3 1 0 2 2 0

2 2 0 1 3 0

3 3 0 0 2 0

2 4 0 1 1 0

4 1 0 2 1 0

2 0 0 4 2 0

4 0 0 0 3 1

1 3 0 2 0 2

3 0 0 2 2 1402

301

450

351

527

254

625

452

502(5)

(7)

(4)

(6)

(2)

(8)

(1)

(9)

(3)