1
Develop an assignment plan that will minimize processing costs, given the information shown, and interpret your answer. (Leave no cells blank - be certain to enter "0" wherever required. Omit the "tiny_mce_markerquot; sign in your response.)
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WORKER
|
| |
|
A |
B |
C |
| |
1
|
12 |
8 |
11 |
| Job |
2
|
13 |
10 |
8 |
| |
3
|
14 |
9 |
14 |
| |
4
|
10 |
7 |
12 |
| |
Total Cost: $
Use the assignment method to obtain a plan that will minimize the processing costs in the following table under these conditions:
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|
WORKER
|
| |
|
A |
B |
C |
D |
E |
| |
1
|
14 |
18 |
20 |
17 |
18 |
| |
2
|
14 |
15 |
19 |
16 |
17 |
| Job |
3
|
12 |
16 |
15 |
14 |
17 |
| |
4
|
11 |
13 |
14 |
12 |
14 |
| |
5
|
10 |
16 |
15 |
14 |
13 |
a. The combination 2-D is undesirable.
The sequence is .
b. The combinations 1-A and 2-D are undesirable.
The sequence is .
2
The following table contains information concerning four jobs that are awaiting processing at a work center.
| Job |
Job Time (Days) |
Due Date
(Days) |
| A |
14 |
20 |
| B |
10 |
16 |
| C |
7 |
15 |
| D |
6 |
17 |
| |
a. Sequence the jobs using (1) First come, first served, (2) Shortest processing time, (3) Earliest due date, and (4) Critical ratio. Assume the list is by order of arrival.
Sequence for First come, first served
Sequence for Shortest processing time
Sequence for Earliest due date
Sequence for Critical ratio
b.
For each of the methods in part a, determine (1) the average job flow time, (2) the average tardiness, and (3) the average number of jobs at the work center. (Round your intermediate calculations and final answers to 2 decimal places.)
First Come, First Served Shortest Processing Time Earliest Due Date Critical Ratio
Average job flow time
Average tardiness
Average number of jobs
c. Is one method superior to the others?
3
The following table shows orders to be processed at a machine shop as of 8:00 a.m. Monday. The jobs have different operations they must go through. Processing times are in days. Jobs are listed in order of arrival.
| Job |
Processing
Time (Days) |
Due Date
(Days) |
Remaining Number
of Operations |
| A |
8 |
20 |
2 |
| B |
10 |
18 |
4 |
| C |
5 |
25 |
5 |
| D |
11 |
17 |
3 |
| E |
9 |
35 |
4 |
|
a. Determine the processing sequence at the first work center using each of these rules: (1) First come, first served, (2) Slack per operation.
Sequence for First come, first served
Sequence for Slack per operation
b. Compute the effectiveness of each rule using each of these measures: (1) average completion time, (2) average number of jobs at the work center. (Round your answers to 2 decimal places.)
First Come, First Served Slack per Operation
Average completion time
Average number of jobs
4
Given the operation times provided:
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JOB TIMES (minutes)
|
| |
A |
B |
C |
D |
E |
F |
| Center 1 |
20 |
16 |
43 |
60 |
35 |
42 |
| Center 2 |
27 |
30 |
51 |
12 |
28 |
24 |
|
a. Develop a job sequence that minimizes idle time at the two work centers.
The sequence is .
b. Determine idle time of center 2, assuming no other activities are involved.
Idle time
5
A shoe repair operation uses a two-step sequence that all jobs in a certain category follow. For the group of jobs listed,
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JOB TIMES (minutes)
|
| |
A |
B |
C |
D |
E |
| Workstation A |
27 |
18 |
70 |
26 |
15 |
| Workstation B |
45 |
33 |
30 |
24 |
10 |
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a. Find the sequence that will minimize total completion time.
The sequence is .
b. Determine the amount of idle time for workstation B.
Idle time minutes
6
The Budd Gear Co. specializes in heat-treating gears for automobile companies. At 8:00 a.m., when Budd's shop opened today, five orders (listed in order of arrival) were waiting to be processed.
| Order |
Order Size
(units) |
Per Unit Time in
Heat Treatment
(minutes/unit) |
Due Date
(min. from now) |
| A |
16 |
4 |
160 |
| B |
6 |
12 |
200 |
| C |
10 |
3 |
180 |
| D |
8 |
10 |
190 |
| E |
4 |
1 |
220 |
| |
a. If the due date rule is used, what sequence should be used?
The sequence is .
b.
What will be the average job tardiness? (Round your answer to 2 decimal places.)
Average job tardiness
c.
What will be the average number of jobs in the system? (Round your answer to 2 decimal places.)
Average number of jobs
d. Would the Shortest processing time rule produce better results in terms of average job tardiness?(Round your answer to the nearest whole number.)
new average job tardiness is minutes.
minutes