Hello Otero,
If you used a Beta distribution when you estimated the optimistic, most
likely and pessimistic durations, you can calcultate for each elementary
task the standard deviation :
STD = (1Opt + 4 likely + 1 Pess)/6
For the whole project, the STD is the square root of the sum of the squared
elementary STD on the critical path.
The project has 68% chance to finish within 1 STD from the mean duration.
The project has 95% chance to finish within 2 STD from the mean duration.
The project has 98% chance to finish within 3 STD from the mean duration.
Hope this help,
Gérard Ducouret
PragmaSoft
Otero said:
How do I calculate the probability that everything in a project will be
ready on time given the the optimistic, most likely, and pessimistic days.
