Question

A partially solved PERT problem is detailed in the table below. Times are given in weeks.

Activity	Immediate Predecessor(s)	Optimistic	Most Likely	Pessimistic
A	--	8	10	15
B	--	7	8	9
C	A	5	6	10
D	A	3	3	3
E	B,D	1	5	9
F	B,D	4	7	10
G	C	3	8	10
H	E	5	7	9
I	E	4	5	8
J	F	2	5	8
K	H, I	1	3	6

a) Calculate the expected duration (D), and variance of each activity.

b) Calculate ES, EF, LS, LF, S) for each activity.

	ET	Variance	ES	EF	LS	LF	S
A
B
C
D
E
F
G
H
I
J
K

c) Which activities form the critical path?

A) ADEHK

B) ACG

     C) ABEK

     D) ADEIK

     E) BFJ

     F) BEHK

d) What is the estimated time of the critical path? ( …… ) weeks
e) If the project is due to be completed in 35 weeks, what is the probability that the project will be completed on the due date? ( … %) ?
f) If the project manager wants at least a 95% probability that the project will be completed on the due date, what is the shortest project due date that will satisfy the manager? ( …… ) weeks
g) Which activity (ies) can be delayed 1.67 weeks without impacting the expected project completion date? A) I B) A      C) C      D) F and G      E) I and J
h) How many week(s) can you delay the activity J, without impacting the expected project completion date? ( ….. ) weeks

Answer 1