Project Management
Forecasting
Please provide detailed solutions to the following problems/exercises (4 problems/exercises):
1) Draw the network corresponding to the following information. Complete the table, identify the critical path, and specify project completion time.
Activity
Immediate Predecessor(s)
Time
(Weeks)
A
—
3
B
—
4
C
A
6
D
B
9
E
B
6
F
C,D
6
G
D,E
8
H
G,F
9
Activity
Earliest
Start
Earliest
Finish
Latest
Start
Latest Finish
Slack
A
B
C
D
E
F
G
H
2) Consider the tasks, durations, and predecessor relationships in the following network. Draw the network and answer the questions that follow.
Activity Description
Immediate
Predecessor(s)
Optimistic
(Weeks)
Most Likely
(Weeks)
Pessimistic
(Weeks)
A
—
4
7
10
B
A
2
8
20
C
A
8
12
16
D
B
1
2
3
E
D, C
6
8
22
F
C
2
3
4
G
F
2
2
2
H
F
6
8
10
I
E, G, H
4
8
12
J
I
1
2
3
a. What is the expected time for activity B?
b. What is the variance for activity B?
c. Based on the calculation of estimated times, what is the critical path?
d. What is the estimated time of the critical path?
e. What is the activity variance along the critical path?
f. What is the probability of completion of the project before week 42?
3) Develop forecasts for periods 7 through 10 for the demand data in the table using a three period moving average, a weighted moving average using 0.6, 0.3, and 0.1, and exponential smoothing with alpha = 0.7. Use a 6th period forecast of 135 as the starting point for the exponential smoothing technique.
Period
Actual
MA n=3
WMA
Exp. Smoothing
1
64
2
84
3
91
4
97
5
115
6
135
7
137
8
144
9
153
10
171
4) Using the data shown in the table, develop a trend line that can be used to predict the demand for time period number 20. What is the prediction equation and what is your forecast for period 20?
Period
Demand
Demand2
Period*Demand
1
16
2
20
3
24
4
27
5
29
6
30
7
32
8
35
9
36
10
38
Sums
55
287