12. Use the assignment method to obtain a plan that will minimize the processing costs in the following table under these conditions:
|
|
|
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.
b. The combinations 1-A and 2-D are undesirable.
13. 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.
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.)
14. The times required to complete each of eight jobs in a two-machine flow shop are shown in the table that follows. Each job must follow the same sequence, beginning with machine A and moving to machine B.
|
|
TIME (hours)
|
|
Job
|
Machine A
|
Machine B
|
|
a
|
16
|
5
|
|
b
|
3
|
13
|
|
c
|
9
|
6
|
|
d
|
8
|
7
|
|
e
|
2
|
14
|
|
f
|
12
|
4
|
|
g
|
18
|
14
|
|
h
|
20
|
11
|
a. Determine a sequence that will minimize makespan time.
b. Find machine B's idle time.
c. For the sequence determined in part a, how much would machine B's idle time be reduced by splitting the last two jobs in half?
16.For each of the following network diagrams, determine both the critical path and the expected project duration. The numbers on the arrows represent expected activity times.
a. Activity-on-arrow diagram
The expected project duration is .
b. Activity-on-node diagram
The critical path is .
The expected project duration is .
c. Activity-on-arrow diagram
The critical path is .
The expected project duration is .
17.For each of the problems listed, determine the following quantities for each activity: the earliest start time, latest start time, earliest finish time, latest finish time, and slack time. List the critical activities, and determine the expected duration of the project.
a. Activity-on-arrow diagram
b. Activity-on-node diagram
c.
|
Activity
|
Immediate
Predecessor
|
Estimated Time (days)
|
|
A
|
-
|
15
|
|
B
|
A
|
12
|
|
C
|
B
|
6
|
|
D
|
B
|
5
|
|
E
|
C
|
3
|
|
F
|
-
|
8
|
|
G
|
F
|
8
|
|
H
|
F
|
9
|
|
I
|
G
|
7
|
|
J
|
H
|
14
|
|
K
|
J
|
6
|
|
End
|
D, E, I, K
|
|
18. Reconsider the network diagram. Suppose that after 12 weeks, activities 1-2, 1-3, and 2-4 have been finished; activity 2-5 is 75 percent finished; and activity 3-6 is half finished. How many weeks after the original start time should the project be finished?
Project can be completed in a total of weeks.
References
eBook& Resources
PROBLEM 2:
Problem 2-6
A manager checked production records and found that a worker produced 180 units while working 40 hours. In the previous week, the same worker produced 123 units while working 30 hours.
a. Compute Current period productivity and Previous period productivity.
b. Did the worker's productivity increase, decrease, or remain the same?
2-7
b. Suppose a new, more standardized procedure is to be introduced that will enable each employee to process one additional customer per day. Compute the expected labor and multifactor productivity rates for each unit.(Round your "Labor Productivity" answers to 1 decimal place and "Multifactor Productivity" answers to 4 decimal places.)
Use α=.5 and β=.1, and TAF of 250 for period 5. Obtain forecasts for periods 6 through 10. (Round your intermediate calculations and final answers to 2 decimal places.)
A manager of a store that sells and installs spas wants to prepare a forecast for January, February, and March of next year. Her forecasts are a combination of trend and seasonality. She uses the following equation to estimate the trend component of monthly demand: Ft = 100 + 2t, where t = 0 in June of last year. Seasonal relatives are 1.13 for January, 1.07 for February, and .92 for March. What demands should she predict? (Round your answers to 2 decimal places.)
https://www.dropbox.com/s/zslrs2qadw7h7e3/Review_Questions.rar?dl=0