2. Jacksonville Bike Shop is behind on a custom bike and needs to crash 1 day of time from the 6-step project. Given the project table below answer the following questions. Suppose this shop calls the customer and asks for a project extension, reducing the amount of time she/he needs to crash. [Note: The project can be speeded up (or "crashed") by spending more money on each activity. For example, activity A currently takes 10 days, but can be reduced to either 9 days or 8 days at additional costs.]
(a) Draw a project network diagram, including activity durations. (Please show all the activities from the starting point to the end.) You may use either AON (Activity On Node) or AOA (Activity On Arrow).
(b) What is the Critical Path in the network?
(c) What is the Project Completion Time?
(d) What is the maximum possible reduction time (indays) for the activity C?
(e) What is the slack time (in days) associated with any and all non-critical paths through the project? If activity D were delayed by two time units (days), what would happen to the entire project duration?
(Please show all your work. You may compute the slack time using ES, EF, LS, and LF.)
(f) Which activities should be crashed, and how much is the minimum additional cost, if the objective is to minimize the total crashing costs, while meeting the deadline of 30 weeks? (Please show all your work.)
|
Activity
|
Immediate Predecessors
|
Normal Time (days)
|
Normal Cost
|
Crash Time (days)
|
Crash Cost
|
|
A
|
__
|
10
|
30
|
8
|
70
|
|
B
|
A
|
8
|
120
|
6
|
150
|
|
C
|
B
|
10
|
100
|
7
|
160
|
|
D
|
A
|
5
|
40
|
4
|
50
|
|
E
|
D
|
10
|
50
|
8
|
75
|
|
F
|
C, E
|
3
|
60
|
1
|
95
|