4.3
[a]. Path 1 (roof): Start  1 3  5  7  8  End
Path 2 (base): Start  1 2  4  6  7  8  End
The theoretical flow time of path 1 is 100 mins and that of path 2 is 127 mins. Path 2 is then
the critical path and the theoretical flow time for the Deluxe model is 127 minutes.
[b]. length of paths 1 and 2 are to 92.5 and 110.5 minutes respectively. theoretical flow time
for a mixture of 75% standard and 25% Deluxe is 110.5 minutes.
[c]. 110.5/4800 = 2.3%
4.4
[a]
See figure 1 below
Figure 1: Flow Chart for Problem Set 4.4 (a)
2 min
1 min
3 min
molding
aut. molding machine
start
eng. ass.
1 molding operator
welding
1 min
3 min
stamping
1 engine assembler
30 min
continuous welding machine
FA
1 welder
end
2 min
10,000lbs press
1 press operator
10 final assemblers
7 min
seat ass.
2 seat assemblers
[b] the critical path is the longest path = 37 minutes (going through seat assembly). the
theoretical flow time = 37 minutes.
[c] try to change the design and process so that we can perform subtasks parallel. Easiest is to
do final assembly of the first three subassemblies first and seat assembly at the end.
4.5
[a]
A process map
Activity
Activity
F1
A
15
min
Process
And
10
Separate
min
B
F2
10
min
Activity
Loan
Officer
15
min
C
20
min
[b]
The theoretical flow time is 50 minutes. The critical path is Activity A, Activity B,
Loan Officer.
[c] The flow time efficiency is 50/7*480 = 50/ 3360= 1.49%
4.6
[a]. theoretical flow time: 17 seconds:
For passenger without additional check (80% of passangers), the theoretical flow time is
(1.5/18)*60 = 5 seconds
For passengers with additional check the theoretical flow time: 65 seconds
The theoretical flow time for an average passenger : 80% *5 + 20% * 65 = 17 seconds
[b] flow time efficiency : 17/ 135 = 12.5%
Problem 5.2
Flow unit = 1 order of 1 dozen.
[a].
1. The theoretical capacities of the resources are: Kristen = 7.5 orders/hour; RM = 15
orders/hour; Oven = 6 orders/hour min.
2. Process Theoretical Capacity = 6 orders of 1 dozen/hr. The oven is the theoretical
bottleneck.
[b] Utilization at full capacity: Kristen = 80%; RM = 40%; Oven = 100%.
[c]
1. Purchasing an additional oven doubles the oven resources pool capacity to 12 orders
per hour. The process capacity, however, is only increased to 7.5 orders per hour as
the bottleneck shifts to Kristen.
2. cross training increases the process capacity to 10 orders per hour.
Problem 5.3
[a] The theoretical capacity is 1.2 garages per hour or $360 per hour.
[b] The bottlenecks are Punch Press –B and Worker PB with a theoretical capacity of 1.5 flow
units per hour.
Unit
Load
Resource Pool
Load
(minutes Batch
per unit)
Theoretical
Capacity
Number Theoretical Capacity
of a Resource Unit of Units of a Resource Pool
(flow units per
hour)
(flow units per hour)
Worker-S
10
1
6.00
1
6.00
Punch Press-R
30
1
2.00
1
2.00
Punch Press-B
50
1
1.20
1
1.20
Worker-PR
30
1
2.00
1
2.00
Worker-PB
50
1
1.20
1
1.20
Forming MachineR
15
1
4.00
1
4.00
Forming MachineB
15
1
4.00
1
4.00
Worker-FR
15
1
4.00
1
4.00
Worker-FB
15
1
4.00
1
4.00
Welding Gun
20
1
3.00
1
3.00
Worker-SA
20
1
3.00
1
3.00
Worker-FA
26
1
2.31
1
2.31
Inspector
50
1
1.20
2
2.40
Table TM-5.1: Theoretical Capacity for Super Garage at MBPF, Inc.
Unit Load (minutes per
unit)
Resource Pool
Standar Fanc Super
d
y
50%25%-
Theoretical
Capacity
Numbe
r
of a Resource Unit of Units
25% Mix
(flow units per
hour)
Theoretical
Capacity
of a Resource
Pool
(flow units per
hour)
Worker-S
10
10
10
10
6.00
1
6.00
Punch Press-R
22
30
30
26
2.31
1
2.31
Punch Press-B
30
50
50
40
1.50
1
1.50
Worker-PR
22
30
30
26
2.31
1
2.31
Worker-PB
30
50
50
40
1.50
1
1.50
Forming
Machine-R
12
15
15
13.5
4.44
1
4.44
Forming
Machine-B
6
10
15
9.25
6.49
1
6.49
Worker-FR
12
15
15
13.5
4.44
1
4.44
Worker-FB
6
10
15
9.25
6.49
1
6.49
Welding Gun
13
20
20
16.5
3.64
1
3.64
Worker-SA
13
20
20
16.5
3.64
1
3.64
Worker-FA
10
15
26
15.25
3.93
1
3.93
Inspector
36
40
50
40.5
1.48
2
2.96
Table TM-5.2: Theoretical Capacity of 50% Standard, 25% Fancy, and 25% Super
garages at MBPF, Inc.
5.5
[a]
The profit from HC is 10* 375 = $3750 per day.
The profit from PC is 9 * 545 = $ 4905 per day
[b]
the best mix is 400 PC and 100 units of HC per day.
5.7
[a].
The bottleneck are the stylists.
[b]
The theoretical capacity will increase to 7.2 customers per hour:
If LuLu does the billing, the unit load of the stylists is reduced to 25 minutes per customer,
and their theoretical capacity increases to 3* 60/ 25 = 7.2 customers per hour. On the other
hand, Lulu’s unit load increases to 3+5 = 8 minutes per hour, and her capacity decreases to
60/8=7.5 customers per hour.