Process Selection and Facility Layout

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CHAPTER 6

• Process Selection and Facility Layout

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Design Product Layouts Line Balancing
3
Objective of line balancing
4
Parameters in line balancing

• Operating time, OT ??? ?????????
• Desired output, D ??? ?????????????????????
• Cycle time, CT ??? ?????????????????? 1 ????
• ????????/??
• Workstation process time, Ti???
  ????????????????????????????????
• Total process time, Tp??? ????????????????????????
  ???????
• ?? ?? ?? ??
• Minimum number of workstation, n???
  ??????????????????????????????????????????????????
  ?
• ?? ?? ?? /????

5
Parameters in line balancing

• Idle time, d ??? ????????????????
• ?? ?? ???? -?? ?? ??(????)

• Efficiency, E ??? ??????????????????
• ??1- ?? ???? -?? ?? ??(????)

???????????????????????????????????????????????
????????????????????????????????????????
???? max?(?? ???? )
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Steps of line balancing

1. Identify the work (job/task).
2. Break down the work into elemental tasks or
   steps.
3. List the various elements along with
   their precedence relationship or logical
   relationships and the time required.
4. Sketch the precedence diagram.
5. Determine the cycle time.
6. Divide the total time by cycle time to get the
   number of work stations required.
7. Assign task to stations or group the elements.
   Total time of all the elements in a group does
   not exceed cycle time.

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Methods of line balancing for assembly line

1. ???????????????????????????????? (Largest
   candidate rule)
2. ??????????????????????????? (Kilbridge and Wester
   method)
3. ???????????????????????????????????? (Ranked
   positional weight method, RPW)

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Methods of line balancing for assembly line

1. ???????????????????????????????? (Largest
   candidate rule)
2. ??????????????????????????? (Kilbridge and Wester
   method)
3. ???????????????????????????????????? (Ranked
   positional weight method, RPW)

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Largest candidate rule
????????
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Largest candidate rule
1. ????? precedence diagram
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Largest candidate rule
2. ????? CT, ??? n
CT OT/D (50)(40)(60) ???? / 120,000
???? 1 ???? Ti 4 ???? n 4/1 4
????? ?????????????????????????????????????? 4
?????
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Largest candidate rule
3. ???????????????????????????????????????????????
???? ???????????????????????????????????????
Cycle time (CT) (1 ???? ?????????????)
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Largest candidate rule
4. ??????????????????????? (idle time)
??????????????????????? (efficiency, E)
idle time
-
0.19
0.02
0.41
0.38
?? ?? ???? -?? ?? ??(????) 5 1 -4.0
(5)(1) 0.220 Efficiency, E 100 20
80
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Methods of line balancing for assembly line

1. ???????????????????????????????? (Largest
   candidate rule)
2. ??????????????????????????? (Kilbridge and Wester
   method)
3. ???????????????????????????????????? (Ranked
   positional weight method, RPW)

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Kilbridge and Wester method
????????
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Kilbridge and Wester method

1. ???????????????????????? column ??????????????

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Kilbridge and Wester method
2. ????????????????????????????????? column
???????????????? ?????????????????????????????
?????????? Cycle time (CT) (1 ???? ?????????????)
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Kilbridge and Wester method
3. ??????????????????????? (idle time)
??????????????????????? (efficiency, E)
idle time
-
0.19
0.08
0.35
0.38
?? ?? ???? -?? ?? ??(????) 5 1 -4.0
(5)(1) 0.220 Efficiency, E 100 20
80
19
Methods of line balancing for assembly line

1. ???????????????????????????????? (Largest
   candidate rule)
2. ??????????????????????????? (Kilbridge and Wester
   method)
3. ???????????????????????????????????? (Ranked
   positional weight method, RPW)

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Ranked positional weight (RPW) method
1. ???????????????????????????????????????????????
????????????????????????????????????
Example ?????? 1 ???????????? ??? 3 4 6 7 8 9
10 11 12 ??????? RWP 3.30 ?????? 11
???????????? ??? 12 ??????? RWP 0.120.5 0.62
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Ranked positional weight (RPW) method
2. ???????????????? RWP ??????????????
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Ranked positional weight (RPW) method
3. ???????????????????????????????????????? cycle
time
idle time
0.1
0.09
0.08
0.35
0.38
?? ?? ???? -?? ?? ??(????) 5 0.92
-4.0 (5)(0.92) 0.1313 Efficiency, E 100
13 87 ?????????? RPW ????????????????????? 2
???????
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Example

• ????????????????????????????????????????????????
  40 ?????????? ??????????????? 8 ?????????????
• ???? Cycle time, ?????????????????????????????????
  ??

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Example
Units required per day
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Example
????????????????????????????????????????????????
40 ?????????? ??????????????? 8 ?????????????
2. ???????????????????????????? Largest
candidate rule ??????????????????????????????????
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Example
CT 12 ???? n 6 ?????
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Example
CT 12 ???? n 6 ?????
?? ?? ???? -?? ?? ??(????) 6 12 -66
(6)(12) 0.0838.3 Efficiency, E 100 8.3
91.7