I\'m working on figuring out this assignment. Can you assistmePart (A): Given th
ID: 3837739 • Letter: I
Question
I'm working on figuring out this assignment. Can you assistmePart (A):Given the following network with tasks, their durations and dependencies, determine the first activity to be crashed by the following rules:
Shortest task first
Minimum slack first
Most critical followers
Most successors
Part (B):
For the above network, crashing information and information on normal completion is provided in the table below:
Based on the information above, compute the crash cost per day.
Arrive at the activities that should be crashed to meet the project deadline of 13 days at a minimum cost. Assume that partial crashing is permitted.
Activity Crash Time (Days) Crash Cost (Total) Normal Time (Days) Normal Cost (Total) A 3 $500 4 $300 B 1 $325 3 $250 C 4 $550 7 $400 D 5 $250 5 $150Explanation / Answer
Answer A): a. By shortest task first, Activity B should be taken up first since it has the shortest time (1 day crash and 3 days normal).
b. By minimum slack first: Slack is defined as difference between deadline 'd', real time 't' and run-time 'c' as:
(d -t) -c. Here, since we'll be calculating for the first task, deadline will be 13 days, real time will be 0.
So, 13 - crash-time is the slack time. For activity D, it is minimum: 13 - 5 = 8. So by minimum slack time with respect to crash time, Activity D should be performed first. For Normal time, Activity C has minimum slack time: 13 - 7 = 6. So, by minimum slack time for normal days, Activity C should be performed first.
c. By Most critical followers, if we assume criticality is same for all activities, then every activity we start will have 3 critical followers. So, any activity can be started at random as first. If cost is taken to decide criticality, Activity C is most critical and could be taken up first.
d. By Most successors, every activity, if taken up first, will have three (equal) successors. So, any activity can be chosen to be taken up first.
Answer (B): Crash cost per day (average) would be = (500 + 325 + 550 + 250)/15 = 1125/15 = 75$ per day.
Crashing could be done in the order of Activity C, Activity A, Activity B, Activity D.