3-Point Estimation

In 3-Point Estimation Expected Value of a task is determined by calculating Mean of 3 different values. These 3 different values are:

• Optimistic Value (O)
• Pessimistic Value (P)
• Most Likely Value (M)

There are two popular methods to arrive at the Expected Value (Mean).

Simple Average

It is based on Triangular Distribution. The Mean can be determined by the following formula.

E_SA=(O+P+M)/3

PERT Formula

PERT (Program Evaluation and Review Technique) is calculated using a Weighted Average. It is based on Beta Distribution. The Mean can be determined by the following formula.

E_PERT=(O+P+4×M)/6

Reduced Risk

A 3-Point Estimation can be done using either Simple Average or PERT Formula. It improves the Estimation accuracy and reduces Project Risk. It provides a better result than just a Single Point Estimate