CSCI 411
Assignment #17 Solution
Monday, March 15, 2015
Chapter 8, Problem #12
A project manager at Kippy Jo’s Cosmetics wishes to determine total human
resource needs for an upcoming marketing campaign involving three of the
company’s products. Each product will be marketed through a different
medium. Precedence relationships for project tasks, along with resource
information, are highlighted in the table below:
Duration
(days)
3
Immediate
Predecessor
None
Resource
Requirement
(# staff members
required per day)
4
B. Research, Product 2
C. Research, Product 3
D. Create Web site, Product 1
E. Prepare TV ads, Product 1
F. Prepare print ads, Product 2
G. Purchase and place TV ads,
Product 2
2
3
2
9
3
3
None
None
A
A
B
B
5
6
6
5
5
2
H. Purchase and place print ads,
Product 3
2
C
4
I. Project completion milestone
0
D, E, F, G, H
0
Task
A. Research, Product 1
a. Draw an AON and time-based network diagram and identify the critical path in each one.
The critical path in this project is A-E. The critical path tasks in the AON and time-based network diagrams are denoted
with heavier borders and arrows:
b. Calculate the daily resource loads for the project. (You may wish to use Excel
although this problem is small enough to lend itself to a manual approach.)
c. Scenario 1, Time Constrained: Revise the schedule to smooth resource
requirements without changing the project’s duration. No task splitting or task
compression (crashing) will be allowed. Write a few sentences about the
managerial implications of this revised schedule.
The critical path in this project is A-E, so no resources can be moved within that path. Because of
the relatively lengthy duration of Task E, the other paths have ample float to work with. Tasks B
and C are research related tasks and therefore it seems more reasonable to keep them scheduled
as early as possible in the schedule. Task F and Task H are similar in that they are both related to
print ads, only for different products. By scheduling those tasks such that they do not overlap, it
might be possible to use the same resources for both tasks. Similarly, both Task E and Task G are
related to TV ads, only for different products. Task E is on the critical path so it cannot be moved;
however, by rescheduling Task G at the end of the project, the resources that worked on Task E
might be able to work on Task G, or at least assist or advise those working on Task G. Finally, by
moving tasks D, F, G, and H further along in the schedule, it affords the research teams some float
in completing their work. Perhaps with more time for research, the project team would be able to
target its audience more accurately when creating media and print ads.
d. Scenario 2, Resource Constrained: Return to the original early-start schedule and
assume the number of staff members has been limited to 10. Reschedule the project to
accommodate this constraint. As in Part C, you may not split or compress tasks. You will
have to change the project’s end date, so your goal will be to meet resource constraints
with the shortest possible project duration. Write a few sentences about the
managerial implications of this schedule.
In the case of scenario 2, the project cannot be completed within the original 12-day time
frame and must be extended to 14 days. With a limit to the daily resources allowed, the project
team resources must be more carefully chosen. Tasks cannot exceed their allotted time on the
schedule so the resources should be chosen accordingly; perhaps more experienced
resources should be used. Because there is no more opportunity for teams to make use of
float between tasks, the schedule must be planned much more carefully to ensure tasks do not
run over their allotted time.
Chapter 8, Problem #13
A new-venture electronics firm is setting up its production facilities in Mexicali,
Baja California, Mexico, located just south of the border with the United States.
Product design is complete. The plant manager has hired 30 people, who possess
mostly interchangeable skills, to prepare the plant. He has asked you to help him
with resource allocation. He is unsure if he can meet the 30-week deadline, given
his resource constraint. Schedule and resource information are shown below.
Task
Immediate
Duration
Predecessor(s) (Weeks)
A. Select site
None
4
B. Design process
None
5
C. Assess materials needs
None
4
D. Arrange lease
A
4
E. Determine skill requirements
B
6
F. Purchase equipment
B
3
G. Establish supplier relationships
C
7
H. Order materials
G
8
I. Hire employees
D, E
5
J. Test equipment
F
5
K. Set up facility
I, J
6
L. Train employees
H,K
4
M. Ramp up production
L
4
People Required
per Week
5
10
20
10
5
10
15
10
5
25
20
25
30
a. Prepare an early-start schedule graph or Gantt chart and produce a histogram to
show the resource loads.
b. Create a revised schedule graph or Gantt chart, with accompanying histogram, to
address the resource constraint of 30 people. (See the next page for revised Gantt
chart. For readability, you may wish to print.)
c. Provide a short explanation for the plant manager about how you derived your revised schedule and
what you recommend.
The first consideration in revising the schedule was the critical path. Tasks within the critical path were
moved as little as possible, especially at the beginning of the project. Paths with float were adjusted as
much as possible before extending the schedule, with priorities placed on the design process, the
buying and testing of equipment, and hiring and training of employees for the plant. Getting the design
process underway was important, whereas securing the site was made less of a priority as there were
many suitable sites available in the region. The tasks involving suppliers and buying supplies were
postponed, which delayed cash outflow until we were closer to building the actual plant.