Three activities are candidates for crashing on a project network for a large co

ID: 2809829 • Letter: T

Question

Three activities are candidates for crashing on a project network for a large computer instaiation (al are, of course, critical) Actvty details are in the following table Total Cost with Normal Time Crash Time Normal Activity (days)(days) Cost Crashing Immediate Predecessorfs) $1.500$3.300 $4,200$6,600 a) Activity that should be crashed first to reduce the project duration by 1 day is b) Activity that should be crashed next to reduce the project duration by one additional day is c) Total cost of crashing the project by 2 days-sl Enter your response as an integer

Explanation / Answer

Crashing cost of the activity is the additional cost which we pay to crash or reduce the activity’s completion time. We can calculate the minimum cost of cashing the project by calculating the crashing cost per day for each activity. The calculation is as follows-

Activity

Normal Time (days)

Crash Time (days)

Normal Cost ($)

Total cost with Crashing ($)

Available days of crashing

(Normal time –crash time)

Crashing cost per day =(crash cost-normal cost)/crashing days ($)

4500

5000

7-6=1

(5000-4500)/1 = 500

1500

3300

4-2=2

(3300-1500)/2= 900

4200

6600

11-9=2

(6600-4200)/2=1200

a. Activity that should be crashed first to reduce the project duration by 1 day is Activity A as the crashing cost is lowest for it.

b. Activity that should be crashed next to reduce the project duration by one additional day is Activity B as the crashing cost is second lowest for it.

c. Total cost of crashing the project by 2 days = 1 * $500 + 1 *$900 = $1,400

Therefore minimum cost of cashing the project by 2 days = $1,400