Consider the following project.

Activity	Immediate Predecessors	Normal Duration (months)	Normal cost ($)
A	-	3	700
B	-	4	900
C	A	2	1,100
D	B	6	600
E	C, D	8	800
F	D	7	1,300
G	E	4	500
H	E, F	9	800

b) For each activity compute ES, EF, LS, LF, and slack. Then, say which activities are critical.

ANSWER to b)

For each activity, compute ES, EF, LS, LF, slack, and critical non-critical activities are as follows:

Activity	Early Start (ES)	Early Finish (EF)	Late Start (LS)	Late Finish (LF)	Slack	Critical
A	0	3	5	8	5	No
B	0	4	0	4	0	Yes
C	3	5	8	10	5	No
D	4	10	4	10	0	Yes
E	10	18	10	18	0	Yes
F	10	17	11	18	1	No
G	18	22	18	22	0	Yes
H	18	27	18	27	0	Yes

Activities B, D, E, G, and H are critical activities.

c) What is the cost of completing the project if its duration is what you obtained in (b)?