Question

A certain project has three activities on its critical path. Activity A’s normal completion time is five days. It can be crashed to three days at a cost of $500. Activity B’s normal completion time is six days, and it can be crashed to four days at a cost of $50. Activity C’s normal completion time is eight days. It can be crashed to three days at a cost of $1,000. Which activity should the project manager crash first, by how many days, and how much will it cost?

Answer 1

Answer:

Acitivy B should be crashed first by 2 days and Activity B has a crash cost per days of $25, it will be crashed for a total of $50.

Explanation:

activity A =

normal time (NT) = 5 days

Normal cost (NC) = $0

crash time (CT) = 3 days

Crash cost (CC) = $500

crash cost per day = [CC - NC]/[CT - NT] = $250/day

activity B:

normal time (NT) = 6 days

Normal cost (NC) = $0

crash time (CT) = 4 days

Crash cost (CC) = $50

crash cost per day = [CC - NC]/[CT - NT] = $25/day

activity C:

normal time (NT) = 8 days

Normal cost (NC) = $0

crash time (CT) = 3 days

Crash cost (CC) = $1000

crash cost per day = [CC - NC]/[ CT- NT] = $200/day

The activity that takes the least cost to speed up is the first one to be crashed. from the computations, activity B takes the least cost to speed up, so the project manager should crash activity B first by 2 days.

Therefore, Acitivy B should be crashed first by 2 days and Activity B has a crash cost per days of $25, it will be crashed for a total of $50.