Operations and Production Management
MGMT 405
Problem set 7
MGMT 405 Operations and Production Management
Problem set 7
(Reference chapters 17– William J. Stevenson-2007, ninth edition)
Discussion Questions
1. Give some examples of ethical issues that may arise on projects. What
can a project manager do to minimize such issues?
2. What are the key advantages of using project management software?
3. List the main advantages of PERT. List the main limitation.
4. Why might a person wish to be involved with a critical path activity?
What are some of the reasons one might have for not wanting this
association?
5. Is the concept of variance of critical path misleading in estimating a
project’s completion time?
6. Explain the concept of:
(a) Expected activity time
(b) Variance of activity time
(c) Standard deviation of a path’s time
© 2010/11, Sami Fethi, EMU, All Right Reserved, McGraw-Hill, 2007, 9. Ed.
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Operations and Production Management
MGMT 405
Problem set 7
7. What are some of the potential benefits of working on a special
project in one’s firm? What are some of risks?
8. What is the main benefit of a project organization over more
traditional forms of operations management for project work?
Problems
1. A student received new word processing software for the student’s birthday. The
student also received a check with which she intends to purchase a new computer.
The student’s college instractor assigned a paper due next week. The student
decided that she/he will prepare the paper on the new computer. She/he made a list
of the activities that she /he will need to do and their estimated times.
Estimated time (hrs.)
Activity
0.8
Install software
0.4
Outline the paper
0.2
submit paper
0.6
choose a topic
0.5
Use grammar check
3.0
write the paper using software
2.0
shop for a new computer
1.0
select and purchase computer
2.0
Library research
© 2010/11, Sami Fethi, EMU, All Right Reserved, McGraw-Hill, 2007, 9. Ed.
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Operations and Production Management
MGMT 405
Problem set 7
(a) Arrange the activities into logical sequences?
(b) Construct an AOA network diagram?
(c) Determine the critical Path and and the expected duration time
(d) What are some possible reasons for project to take longer than the expected
duration?
2. The following table contains information related to the major activities of a
research project. Use the information to do the following: each case may require
the use of a dummy activity.
Immediate
Expected
Predecessor
Time (days)
a
-
5
b
-
8
c
-
2
d
a
7
e
b
3
f
b
6
g
c
10
h
f
8
i
f,g-
15
k
d,e
2
end
h,i,k
-
Activity
© 2010/11, Sami Fethi, EMU, All Right Reserved, McGraw-Hill, 2007, 9. Ed.
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Operations and Production Management
MGMT 405
Problem set 7
(a)
Draw a precedence diagram using AOA
(b)
Find the critical path based AOA.
(c)
Determine the expected length of the project.
3. Using the information on the following diagram and calculate the amount of
slack time for each path as well as ES, EF, LS and LF
5
4
2
7
9
10
2
4
3
2
8
12
5
1
6
8
7
10
5
11
4
3
6
h
9
6
© 2010/11, Sami Fethi, EMU, All Right Reserved, McGraw-Hill, 2007, 9. Ed.
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Operations and Production Management
MGMT 405
Problem set 7
4. Given the following diagram:
Compute (a) the expected time (b) the expected duration (c) Identify the critical
(d) path The variance (e)The std. deviation (f) the probability that the project
can be completed within 26 weeks of its start (project manager receives a bonus
of $ 1000) (g) the probability that the project can be completed within 27 weeks
of its start (project manager receives a bonus of $ 500). Before complete the
sections, do not forget to draw its AOA diagram.
Activity
A
D
E
H
F
G
B
I
J
K
C
M
N
0
End
Predecessor
Time(weeks)
-
2-4-6
A
D
E
A
F
6-8-10
7-9-12
2-3-5
3-4-8
5-7-9
2-2-3
2-3-6
3-4-5
4-5-8
5-8-12
1-1-1
6-7-11
8-9-13
B
I
J
C
M
N
H, G, K, 0
5. Indirect costs for a project are $12,000 per week for as long as the
project lasts. The project manager has supplied the cost and time
information shown. Use the information to
a. Determine an optimum crashing plan.
b. Graph the total costs for the plan.
© 2010/11, Sami Fethi, EMU, All Right Reserved, McGraw-Hill, 2007, 9. Ed.
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Operations and Production Management
MGMT 405
Problem set 7
© 2010/11, Sami Fethi, EMU, All Right Reserved, McGraw-Hill, 2007, 9. Ed.
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