Question

Set up and solve an LP model using Excel to crash this project to 24 days. What is the total crashing cost?

ACTIVITY	IMMEDIATE PREDECESSORS	STANDARD TIME (Days)	STANDARD COST	CRASH TIME (Days)	CRASH COST
A	--	7	$2,000	5	$3,500
B	A	10	$3,000	8	$4,700
C	A	8	$3,400	7	$3,700
D	C	6	$1,600	4	$2,600
E	C	7	$1,900	4	$4,000
F	D,E	5	$1,200	3	$2,800
G	B,C	11	$8,200	8	$10,900
H	F,G	4	$2,600	3	$3,800

Answer 1

			Results
Data				Normal time	32						Minimum crash cost to meet project goal	$      9,700
Project goal	24			Minimum time	24						Project time	24
					Immediate Predecessors (1 per column)						Intermediate Computations
Activity	Normal Time (weeks)	Crash Time (weeks)	Normal Cost	Total Cost with Crashing	Pred 1	Pred 2	Pred 3	Pred 4		Crash days	Crash cost/day	Crash limit
A	7	5	$2,000	$3,500						2	750	2
B	10	8	$3,000	$4,700	A					2	850	2
C	8	7	$3,400	$3,700	A					1	300	1
D	6	4	$1,600	$2,600	C					0	500	2
E	7	4	$1,900	$4,000	C					1	700	3
F	5	3	$1,200	$2,800	D	E				2	800	2
G	11	8	$8,200	$10,900	B	C				3	900	3
H	4	3	$    2,600	$       3,800	F	G				1	1200	1

The total crashing cost is $9,700.