Question

The following activities are part of a project to be scheduled using CPM:

ACTIVITY	IMMEDIATE PREDECESSOR	TIME (WEEKS)
A	—	3
B	A	9
C	A	5
D	C	2
E	B D	7
F	D	6
G	E F	4

b. What is the critical path?

	A-B-D-F-G
	A-B-E-G
	A-C-D-F-G
	A-C-D-E-G

c. How many weeks will it take to complete the project?

Number of weeks            

d. How much slack does activity B have?

Slack of activity B             week(s)

Answer 1

step 1	find early start, and early finish from the start of the project for each activity
step 2	Find Maximum EF and keep it as the LF of last activities. Max of EF's is 23
step 3	calculate LS for each activity after calculating its EF

Activity	Duration, D	Early start, ES=Max of early finish of preceding activities	Early finish, EF = ES + D	Late finish, LF= Min of LS of successor activities	Late start, LS= LF - D	Total slack= LF-EF	Critical activity, activities with 0 slack time
A	3	0	3	3	0	0	Yes
B	9	3	12	12	3	0	Yes
C	5	3	8	10	5	2	No
D	2	8	10	12	10	2	No
E	7	12	19	19	12	0	Yes
F	6	10	16	19	13	3	No
G	4	19	23	23	19	0	Yes

b. Hence the critical path is A-B-E-G

c. it will take 23 weeks

d. slack of B is 0.