Problem 5-20 (Static)

Assume the network and data that follow:

ACTIVITY	NORMAL TIME (WEEKS)	NORMAL COST	CRASH TIME (WEEKS)	CRASH COST	IMMEDIATE PREDECESSORS
A	2	$50	1	$70
B	4	80	2	160	A
C	8	70	4	110	A
D	6	60	5	80	A
E	7	100	6	130	B
F	4	40	3	100	D
G	5	100	4	150	C, E, F

b. Indicate the critical path when normal activity times are used.

multiple choice 1

A-B-E-G Correct

A-D-E-G

A-D-F-G

A-C-F-G

c. Demonstrate the crashing steps needed to minimize the cost of crashing down to various project lengths. Consider project lengths of 18, 17, 16, 15, 14, and 13 weeks. For each possible step down in project length, specify which activity would be crashed to achieve that length, compute the resultant length of each path in the project, and compute the crashing costs as shown in the table below.

Note: Leave no cells blank - be certain to enter "0" wherever required.

Project Duration: 18 weeks 17weeks 16weeks 15weeks 14weeks 13weeks

Length of path ABEG

Length of path ACG

Length of path ADFG

Activity crashed

Crash cost for this step

Cumulative crash cost

Total direct cost

d-1. If the indirect costs for each project duration are $400 (18 weeks), $350 (17 weeks), $300 (16 weeks), $250 (15 weeks), $200 (14 weeks), and $150 (13 weeks), what is the total project cost for each duration?

Duration Total Cost

18

17

16

15

14

13

d-2. Indicate the minimum total project cost duration.

multiple choice 2

13 weeks

14 or 15 weeks

17 weeks

16 or 15 weeks Correct