Question

a)Fill in the network diagram below

Task	Time (wk)	Predecessor	Min Time with Crashing	Crashing cost/wk	ES	EF	LS	LF	Slack	Critical (Y/N)	Free Slack
A	5	-	4	$50
B	3	-	2	$10
C	6	A	3	$2,500
D	3	A	1	$10
E	8	C,B	7	$200
F	3	D,E	1	$1,000
G	4	F	4	-
Task	Time (wk)	Predecessor	Min Time with Crashing	Crashing cost/wk	ES	EF	LS	LF	Slack	Critical (Y/N)	Free Slack
A	5	-	4	$50
B	3	-	2	$10
C	6	A	3	$2,500
D	3	A	1	$10
E	8	C,B	7	$200
F	3	D,E	1	$1,000
G	4	F	4	-

b-Clearly List your critical path

c-What is the shortest time need to complete the project (without expediting)?

d-To expedite the project by two weeks, which activities will you crash? Crashing cost?

Answer 1

Answer:

a.

b. Critical Path: A-C-E-F-G

c. 26 weeks

Shortest time to complete project is 26 weeks. (Earliest Finish time of Activity G - Last activity on critical path)

d. A,E. Cost: $250

To reduce the project duration, we need to crash the activities on critical path.

Activity A has the lowest crashing cost among all activities on critical path. Max possible crashing is 1 week.

Activity E has the 2nd lowest crashing cost among all activities on critical path. Max possible crashing is 1 week.

Crash the Activities A and E by 1 week to reduce the project duration by 2 weeks.

Crashing Cost = Crashing Cost of A + Crashing Cost of E = 50 +200 = $250