Transcript Capacity Management

Session 14
Capacity Management
http://www.pom.edu/mpc/lectures_in_manufacturing_planning.htm
lecture session 15
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Capacity Planning Issues
Finite Capacity Planning Example
Twin Disc Capacity Bills Example
Applicon Capacity Bills Example
Concluding Principles
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Capacity Planning Issues
• To determine the capacity required to achieve the MPS
relative to the capacity available
• To make necessary capacity adjustments before creating
crises
• To determine an the appropriate level of safety capacity
• To determine the required level of detail and the critical
machines and work centers
• To use an appropriate technique given the tradeoff
between accuracy and computational effort
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Finite Capacity Planning Example
The Single Square Company summarizes the capacity
requirements for three of its key resources from each
of its three product lines. A typical report (before any
action is taken) is shown on the next slide.
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Finite Capacity Planning Example
(Continued)
Key resource type
Machine Number Shifts
Drill 1 1
3
Drill 2 2
3
Drill 3 1
1
Percent capacity by line
A
B
C
22
13
24
36
48
36
52
24
21
Total
59
120
97
Filer 1
Filer 2
2
3
3
3
2
12
0
20
14
8
16
40
Dryer 1 2
Dryer 2 2
Dryer 3 2
2
2
1
28
72
84
36
51
27
51
43
24
116
116
135
a.
b.
Remarks
What actions would you recommend? (Assume each
machine type is equivalent in terms of capacity.)
What other observations would you have for
management, based on the preceding report?
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Finite Capacity Planning Example:
Single Square Company
Key Resource Type
Machine Number Shifts
Drill 1
1
3
Drill 2
2
3
Drill 3
1
1
Total
3
6
1
10
% Capacity by Line
A
B
22
13
36
48
52
24
C
24
36
21
Tot.
59
120
97
Equiv.
1.77
7.20
.97
9.94
Remarks
Req'd.
Move
from
2 to 1
Filer 1
Filer 2
2
3
3
3
6
9
15
2
12
0
20
14
8
16
40
.96
3.60 _
4.56
Excess
capacity
Dryer 1
Dryer 2
Dryer 3
2
2
2
2
2
1
4
4
2
10
28
72
84
36
51
27
52
43
24
116
166
135
4.64
6.64
2.70
13.98
Increase
to three
shifts
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Finite Capacity Planning Example:
Single Square Company (continued)
a. There is enough capacity now in the Drill and Filer areas. To
correct the imbalance in the Drills, it is necessary to move
some of the load from Drill 2 to Drill 1. In the case of the
Dryers, it is necessary to increase capacity. Adding shifts will
provide enough for the current load.
b. Why is there so much capacity for the Filers? They can be
brought back to one shift and are okay. Secondly, if there is
any upward trend in the loads for the Dryers, it behooves
management to begin to worry about where they can get
additional dryer capacity.
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Twin Disc Capacity Bill Report
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Twin Disc Capacity Bill Example
Suppose, in the Twin Disc example, it was decided to
move all production for product lines F and I from the
Maag grinder (CEA) to the Reishauer grinder (CAB).
What's the resulting total percentage of capacity for each
machine and the amount for product lines F and I? (Note
the Reishauer is three times faster than the Maag
grinder so the Maag takes three times as many hours to
complete a job.) Assume setup time is negligible.
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Twin Disc Capacity Bill Example
For Line I
Grinding Hours
On Maag
= 3044 x .08 = 243.52
On Reishauer
= 243.52/3 = 81.17
% of Reishauer
= 81.17/950 = 9
New % of Line I on Reishauer = 9 + 1 = 10%
New % of Line I on Maag
= 0%
For Line F:
Grinding Hours
On Maag
= 3044 x .05 = 152.20
On Reishauer
= 152.20/3 = 50.73
% of Reishauer
= 50.73/950 = 5
New % of Line F on Reishauer = 5 + 2 = 7%
New % of Line F on Maag
= 0%
New Totals:
New total for Reishauer
New total for Maag
= 69 + 9 + 5 = 83%
= 113- 8 - 5 = 100%
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Applicon Capacity Status Report
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Applicon Capacity Bill Example
Applicon has the following capacity bills for items 207
and 208:
207
Work center Hours/unit
ALF-A
0.5
HLT-A
1.0
MIS-A
0.8
MVX-A
0.8
PCB-A
0.5
PCB-P
1.0
208
Work center Hours/unit
ALF-T
0.3
HLT-T
0.8
MIS-T
0.6
MVX-T
0.5
PCB-P
0.9
PCB-T
1.4
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Applicon Capacity Bill Example
a. A customer wants to know if Applicon can deliver 100
units each of items 207 and 208 during the next month
(20 working days). Assume there are adequate
materials, work center MVX-T'S crew has been
increased to one full person (making standard
capacity = 160), the increase has come by reducing
MVX-A to 6.5 persons. and no other orders have been
booked. Use the standard capacity data and
conditions in the previous slides as the basis for your
analysis.
b. Suppose the customer (in part a. above) decided to
delay the order for several months. How many units of
item 207 alone could be added to the MPS in the next
month? How about item 208?
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Applicon
Analysis:
For Item 207
Work Center
ALF-A
HLT-A
MIS-A
MVX-A
PCB-A
PCB-P
Units Possible
(480 - 70)/0.5 = 820 units
(800 - 438)/1.0 = 362 units
(800 - 270)/0.8 = 662 units
(1120 - 80 - 399)/0.8 = 801 units
(160 - 52)/0.5 = 216 units
(960 - 408)/1.0 = 552 units
BUT this is if only item 207 is made.
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Applicon
If BOTH items are made in equal quantities, PCB-P is a
shared work center so:
PCB-P
(960 - 408)/(1.0 + 0.9) = 291 of each.
For Item 208
Work Center
Units Possible
ALF-T
(80 - 5)/0.3 = 250 units
HLT-T
(160 - 85)/0.8 = 94 units
MIS-T
(80 - 14)/0.6 = 110 units
MVX-T (160 - 79)/0.5 = 162 units
PCB-P (960 - 408)/(1.0 + 0.9) = 291 units
PCB-T
(1680 - 918)/1.4 = 544 units
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Applicon
a. The analysis says that 100 units of each
cannot be added to the MPS without
something else being done. The problem is
with item 208 in work center HLT-T. To make
100 units of item 208, work center HLT-T will
have to work overtime-unless capacity can be
provided from a less highly utilized work center
or perhaps greater productivity can be gained
in some other way.
b. The analysis shows that 216 units of item 207
or a total of 94 units of item 208 can be made.
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Concluding Principles
• Capacity plans must be developed concurrently with
material plans if the material plans are to be realized.
• The capacity measure should reflect realizable output from
the key resources.
• It's not always capacity that should change when capacity
availability doesn't equal need.
• Capacity not only must be planned, but use of that capacity
must also be monitored and controlled.
• Capacity planning techniques can be applied to selected
key resources (which need not correspond to production
work centers).
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Concluding Principles
• The particular capacity planning technique(s) chosen must
match the level of detail and actual company circumstances
to permit making effective management decisions.
• The more detail in the capacity planning system, the more
data and data base maintenance are required.
• The better the resource and production planning process, the
less difficult the capacity planning process.
• The better the shop-floor system, the less short-term capacity
planning is required.
• Capacity planning can be simplified in a JIT environment.
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