Question

Activity	Optimistic(ta)	Most Likely(tm)	Pessimistic(tb)	Predecessor
A	4	5	6	___
B	5	6	8	___
C	3	4	7	___
D	4	5	6	A
E	3	3	3	A
F	3	4	8	B
G	5	8	12	C
H	1	1	1	D
I	1	2	3	E, F
J	2	3	6	G
K	4	7	9	I, J
L	2	5	7	H, K

a. Find the following:

-Expected Time(te)

-Variance(σ2)

-ES, LS, EF, LF, and S.

-critical path.

b. Find the probability that the project will not be completed in the expected time (CT) + 5 days?

Answer 1

a)

Critical path is the longest path which is C-G-J-K-L having duration 27.5 days

Formula

b)

Expected completion time = duration of critical path = 27.5 days

z = (x-Expected completion time)/project standard deviation

= 5/sqrt(3.638888889)
= 2.62111217

probability of getting the project completed within expected time (CT) + 5 days = NORM.S.DIST(2.62111217,TRUE) = 0.995617829

So, probability that the project will not be completed in the expected time (CT) + 5 days = 1-0.995617829 = 0.004382171