Problem 1: Consider the following project network and activity times (in days):
|
Activity
|
A
|
B
|
C
|
D
|
E
|
F
|
G
|
|
Time 1
|
3
|
2
|
5
|
5
|
6
|
2
|
2
|
The crashing data for this project are as follows:
|
|
Times (days)
|
Cost ($)
|
|
Activity
|
Normal
|
Crash
|
Normal
|
Crash
|
|
A
|
3
|
2
|
800
|
1400
|
|
13
|
2
|
1
|
1200
|
1900
|
|
C
|
5
|
3
|
2000
|
2800
|
|
D
|
5
|
3
|
1500
|
2300
|
|
E
|
6
|
4
|
1800
|
2800
|
|
F
|
2
|
1
|
600
|
1000
|
|
G
|
2
|
1
|
500
|
1000
|
a. Find the critical path and the expected project completion time.
b What is the total project cost using the normal times?
Problem 2: Refer to Problem 1. Assume that management desires a 12-day project completion time. Formulate a linear programming model that can be used to assist with the crashing decisions.
b. What activities should be crashed?
c. What is the total project cost for the 12-day completion time?
Problem 3: Office Automation, Inc., developed a proposal for introducing a new computerized office system that will standardize the electronic archiving of invoices for a particular company. Contained in the proposal is a list of activities that must be accomplished to complete the new office system project. Use the following relevant information about the activities:
|
|
|
Immediate
|
Time (weeks)
|
Cost ($1000s)
|
|
Activity
|
Description
|
Predecessor
|
Normal
|
Crash
|
Normal
|
Crash
|
|
A
|
Plan needs
|
-
|
10
|
8
|
30
|
70
|
|
B
|
Order equipment
|
A
|
8
|
6
|
120
|
150
|
|
C
|
Install equipment
|
B
|
10
|
7
|
100
|
160
|
|
D
|
Set up training lab
|
A
|
7
|
6
|
40
|
50
|
|
E
|
Conduct training course
|
D
|
10
|
8
|
50
|
75
|
|
F
|
Test system
|
C, E
|
3
|
3
|
60
|
-
|
a. Develop a project network.
b. Develop an activity schedule.
c. What are the critical activities, and what is the expected project completion time?
d. Assume that the company wants to complete the project in six months or 26 weeks. What crashing decisions do you recommend to meet the desired completion time at the least possible cost? Work through the network and attempt to make the crashing decisions by inspection.
e. Develop an activity schedule for the crashed project.
f. What added project cost is required to meet the six-month completion time?