What is three-point estimation?

Three-point estimation is a method of estimating the time or resources required to complete a task based on three values:

• Optimistic estimate (O) — the minimum time in which the task can be completed under ideal conditions.
• Pessimistic estimate (P) — the maximum time that might be needed, considering possible problems.
• Most likely estimate (M) — the most realistic time to complete the task.

The expected time (E) is calculated using these three estimates with the formula:

E = (O + 4M + P) / 6

This approach helps account for uncertainty and risks in planning, making estimates more accurate and justified. It is often used in project management for scheduling and deadline estimation.