Delphi technique

The Delphi technique is a structured information-gathering and consensus technique in which a group of experts answers questionnaires anonymously, in several rounds, with a facilitator summarising the answers after each round. It was developed by the RAND Corporation in the 1950s. In project management it is used for risk identification, estimating (cost, time, effort) and forecasting.

Process

Select experts -> Round 1 questionnaire
   -> Collect anonymous responses
   -> Facilitator summarises -> Feedback to experts
   -> Round 2 (revise opinions) -> ... -> Consensus

1. Select a panel of experts (not meeting face to face).
2. Define the problem and prepare the questionnaire.
3. Round 1: experts give opinions or estimates anonymously.
4. Facilitator compiles and summarises results with reasons.
5. Feedback: the summary goes back to experts, who revise their views.
6. Repeat for 2-4 rounds until responses converge.
7. Final report with the consensus.

Characteristics

• Anonymity prevents dominance by strong personalities and bandwagon effects.
• Iteration with controlled feedback.
• Statistical group response (median, range).
• Experts can be geographically dispersed.

Advantages

• Reduces bias and group pressure.
• Uses expertise of many people.
• Low cost; no meetings needed.
• Good for uncertain problems with little data.

Disadvantages

• Time-consuming (many rounds).
• Depends on quality of experts and facilitator.
• Consensus may hide valid minority views.
• Low response can weaken results.

Example: To identify risks in a nationwide ERP rollout, ten experts list risks anonymously, the facilitator groups them, and after three rounds the team agrees on the top 15 risks and probability ratings.