What is different between Triangular Distribution and Beta Distribution Saving Changes...
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Poonam JainProject Manager| Morgan StanleyHicksville, Ny, United States
1. Triangular distribution:
Triangular Distribution: E = (o + m + p ) / 3
where E is Estimate; o = optimistic estimate; p = pessimistic estimate; m = most likely estimate
2. Beta (or PERT):
Beta Distribution (PERT): E = (o + 4m + p ) / 6
The beta distribution is a weighted average in which more weight is given to the most likely estimate. This alteration to the formula and placing more weight on the most likely estimate is made to increase the accuracy of the estimate by making it follow the Normal Distribution shape. Hence, in most of the cases, the Beta (PERT) distribution has been proven to be more accurate than the 3-Point triangular estimation.
For Activity A:
o = 3 hours , m = 8 hours , p = 17 hours
Triangular Distribution:
E = (3 + 8 + 17 ) / 3
E = 24 / 3
E = 9.3 hours
Beta Distribution (PERT):
E = (3 + 4(8) + 17) / 6
E = 52 / 6
E = 8.7 hour Saving Changes...
Tamer Zeyad SadiqAssistant Cost Manager| Turner & TownsendRiyadh, Ar Riyad, Saudi Arabia
You can find in PMBOK related to Time Management!!! Saving Changes...
Sergio Luis ConteHelping to create solutions for everyone| Worldwide based OrganizationsBuenos Aires, Argentina
Just to comment, Beta distribution is not a synonim of PERT. In fact, when you use tools to simulate schedule variances the hard part, just in case you need to get accurancy into the results, is you have to define the distribution that best represent each activity or group of activities then you will find that some are triangular, some are square, some are beta, and so on. The best way to understand it is going to the basement that you will find into statistic field. If you have to deal with that then you will need some mathematical knowledge. Saving Changes...
