How do you estimate in the three point estimating method?

by

There are 2 formulas to calculate 3 point estimation.
1) Triangular Distribution E = (P+M+O)/3 ;
2) Beta or PERT Distribution E = (P+4M+O)/6 ;

where P stands for pessimist, O for Optimist and M = most likely and
PERT = Program Evaluation and Review Techniques

In project management, the three-point estimating method is a technique used to provide more accurate and realistic estimates for project tasks. It involves considering three different estimates for the time, effort, or cost required for each task: an optimistic estimate (O), a pessimistic estimate (P), and a most likely estimate (M). The formula used to calculate the expected value (E) based on these three estimates is typically the Triangular Distribution:

�=(�+4�+�)/6E=(O+4M+P)/6

Here’s how you would estimate using the three-point estimating method:

  1. Optimistic Estimate (O): This is the best-case scenario estimate. You consider what the task duration, effort, or cost would be if everything goes exceptionally well. It is denoted as “O.”
  2. Pessimistic Estimate (P): This is the worst-case scenario estimate. You consider what the task duration, effort, or cost would be if everything goes wrong or if there are significant obstacles. It is denoted as “P.”
  3. Most Likely Estimate (M): This is the most realistic estimate based on your knowledge and experience. It takes into account typical conditions, resources, and challenges. It is denoted as “M.”

Once you have these three estimates, you can plug them into the formula mentioned above to calculate the expected value (E). The expected value represents the average or most likely outcome based on the three estimates provided.

During an interview, you can explain this process by emphasizing the importance of considering best-case, worst-case, and most likely scenarios to arrive at a more informed and realistic estimate for project tasks. Additionally, highlighting how this method helps in risk management and decision-making processes within the project can demonstrate your understanding of its significance in project management.