Chapter 5 – Managing the Test Activities
Three-Point Estimation – ISTQB Definition
Last Updated: July 12, 2026 · SoftwareTestPilot QA Team
Official ISTQB Definition
An expert-based estimation technique that uses optimistic, most likely and pessimistic estimates to calculate an expected value.
In simple words
Estimate best-case, worst-case and most-likely, then combine: E = (O + 4M + P) / 6.
Exam tip
Three-point estimation is the PERT formula and shows up on both ISTQB and PMP exams.
Related terms
- Test Effort EstimationEstimate how much time and how many people the testing will need, using metrics, expert judgment or comparison to past projects.
- Wideband DelphiExperts estimate anonymously in rounds, discuss the outliers, and repeat until they converge.
- Planning PokerA game where everyone flips an estimate card at the same time to avoid anchoring.
Practice this term in the ISTQB Mock Test
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