Estimation is one of the important area, which get managed by project manager along with sales team. Some time requirement of the project is very much complex and base upon lots of assumptions towards features and functions. So, to overcome that PERT estimation is the key . It minimize the risk element for estimated value for any project.
PERT [ Program Evaluation & Review Technique ] – derived during research work carried out by the U.S. navy in the year 1950. It derived while they were trying to complete the Polaris Fleet Ballistic Missile Project on pre design schedule. After getting successful result as outcome they implement in to management strategy and find very good result out of them. Since 1950 PERT get utilized as one of the most effective tool for evaluation and review.
For IT, this is one of the most effective strategy. As we know that few project manager or leader are use to provide estimation with optimistic view and some of them provide it with pessimistic view. So, one time project estimate is not suffice to get accuracy of the project. Therefore by PERT estimation technique we ensure about minimizing or eliminating risk factors into estimates. Lets check
how we can derive PERT estimation.
We need to identify risk at three different level :
Level 1 (TOPT) – Estimate with the most optimistic view ( Consider that chances of risks are few )
Level 2 (TLIKELY) – Estimation with the most likely or Average view (Consider that chance of risks are average )
Level 3 (TPESS) – Estimation with the most pessimistic view (Consider that chance of risks are very low)
The Pert Formula:
Estimate = Pessimistic + (4X Average) + Optimistic / 6 [six]
1 Base upon project analysis or , WBS we need to define these basic three levels:
2. Use the PERT formula to derive calculation of a final “Single estimate”
3. Apply the “single estimate” to each item in the WBS to derive estimation.
Business development or sales team can use this for big size project to ensure zero risk deal base upon expert’s opinion.