wideband Delphi
A consensus-driven estimation technique where subject matter experts first submit independent estimates across multiple iterations, then meet to review and discuss after each round, refining numbers until agreement is reached.
Key Points
- Iterative rounds of independent estimating followed by facilitated group discussion.
- Aim is to converge on a common estimate and reduce bias and anchoring.
- Often includes a neutral facilitator and may anonymize inputs to prevent dominance.
- Useful when data is uncertain for scope, cost, duration, or risk estimates.
Example
An agile team must estimate the effort to integrate a new payment gateway. Each SME privately submits an effort estimate. The facilitator shares a summary, the team discusses assumptions, and everyone re-estimates. After several rounds, the group aligns on a consensus range of 40 to 48 hours with agreed assumptions documented.
PMP Example Question
Which estimating technique has experts provide independent estimates over several rounds, with team discussions after each round, to reach consensus?
- Wideband Delphi
- Analogous estimating
- Planning poker
- Three-point estimating
Correct Answer: A — Wideband Delphi
Explanation: Wideband Delphi uses multiple cycles of independent estimates followed by group review to reach agreement, unlike analogous (historical comparison), planning poker (quick consensus via cards), or three-point estimating (optimistic/most likely/pessimistic).
