Question

Given the data in the spreadsheet below, what is the probability of completing the critical path of the project in 34 or more time units?

Activity	Preceded By	Optimistic Time	Most Likely Time	Pessimistic Time
A	None	12.89	15.25	18.21
B	None	14.17	15.61	18.13
C	A and B	12.33	14.2	17.98
D	A and B	14.84	17.64	20.53

Answer 1

z = (34 - 33.445)/1.16 = 0.48

P (z > 0.48) = 0.3155

The probability of completing the critical path of the project in 34 or more time units is 0.3155.

The other calculations are:

Activity	Optimistic	Likely	Pessimistic		Mean	Std dev	Variance
A	12.89	15.25	18.21		15.35	0.886667	0.786178
B	14.17	15.61	18.13		15.79	0.66	0.4356
C	12.33	14.2	17.98		14.51833	0.941667	0.886736
D	14.84	17.64	20.53		17.655	0.948333	0.899336
Precedences
Activity	Time	Pred 1	Pred 2
A	15.35
B	15.79
C	14.51833	A	B
D	17.655	A	B
Results
Activity	Early Start	Early Finish	Late Start	Late Finish	Slack		Variance	Critical Variance
A	0	15.35	0.44	15.79	0.44		0.786178
B	0	15.79	0	15.79	0		0.4356	0.4356
C	15.79	30.30833	18.92667	33.445	3.136667		0.886736
D	15.79	33.445	15.79	33.445	0		0.899336	0.899336
	Project	33.445					Project	1.334936
							Std.dev	1.155394

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