I found PERT examples include a formula
(a + 4m + b)/6
where a= optimistic time , b= pessimistic time and m= actual time to complete the task
but how to calculate a and b? please help me as soon as possible
+1
A:
You don't calculate a and b, you estimate them. And m is usually the most likely time (estimate) not the actual time.
How do you estimate them?
That's a hard question... you need to consider the best possible scenario, and the worst. It takes practice and experience. You will likely get it wrong the first few times.
Mark Byers
2010-05-02 07:56:09
http://www.netmba.com/operations/project/pert/This link says "Optimistic time - generally the shortest time in which the activity can be completed. It is common practice to specify optimistic times to be three standard deviations from the mean so that there is approximately a 1% chance that the activity will be completed within the optimistic time" -- > is there any mathematical formula to calculate it?
karthi
2010-05-02 08:23:39
@karthi: No there is not. From the page you linked to "The activity time estimates are somewhat subjective and depend on judgement."
Mark Byers
2010-05-02 08:52:30