The Delphi technique, also known as the Delphi method or Delphi forecasting, is a forecasting or estimating method based on a discussion by a group of experts.
The technique consists of several rounds of individual and anonymous questions to each expert, followed by a group discussion after every round. The latter allows participants to reflect and adjust their opinions. The process is usually repeated until a consensus is achieved, usually ending with three or four iterations.
While such discussions can happen in person, an alternative is to send out a series of paper or online questionnaires. In this case, a written summary of all responses is distributed to everyone after each round, instead of a group discussion.
Delphi Characteristics
The following key characteristics of the Delphi method help the participants to focus on the issues at hand and separate Delphi from other methodologies: in this technique a panel of experts is drawn from both inside and outside the organisation. The panel consists of experts having knowledge of the area requiring decision making. Each expert is asked to make anonymous predictions.
Delphi Process
The Delphi technique is useful for situations that allow for a range of scenarios or opinions, such as estimating the duration of tasks, identifying project risks and forecasting their probability, or allocating the resources. It consists of following steps
- Select a facilitator: Choose a person who will be moderating the discussion. This can be either the project manager or someone independent to the project to ensure impartiality. John has decided to facilitate the discussion himself.
- Select the experts: Choose the people with relevant knowledge on the subject to participate in a panel: These could include the client, the project team, or industry experts from outside the company. John has invited the project sponsor, the company CEO, two leading engineers from the company, two engineering specialists from outside the company, and the contractor representative to participate in the process.
- Define the problem: To arrive at a relevant and comprehensive decision, it’s crucial to define the problem that has to be solved (or the conditions for the forecast to be made) as precisely as possible. Before the first session, John has e-mailed all participants, explaining that the main goal of the sessions will be to arrive at the construction duration estimate. The pre- and post-construction works will be discussed and estimated separately.
- First round of questions: During the first round, it is a good idea to start with broad, possibly open-ended questions. The facilitator collects the replies from all participants and reviews them before initiating the discussion, highlighting the common opinions. On Monday, John sends out a set of questionnaires to everyone electronically and asks to return their estimates by the end of the week. It then takes him two days to consolidate the replies. He schedules the first meeting and the group discusses the various possibilities and contingencies for constructing the skyscraper.
- Repeat until consensus: The rounds of questions and discussions should be repeated until a general agreement has been reached, and all experts support a certain decision or estimate.
- Implementing the decision: After the end of the discussion, the results should be analyzed and a plan of action should be created based on the recommendations from the experts. Based on the estimation created, John updates the project plan for the construction of the skyscraper.
Variations
Traditionally the Delphi method has aimed at a consensus of the most probable future by iteration. Other versions, such as the Policy Delphi, is instead a decision support method aiming at structuring and discussing the diverse views of the preferred future. In Europe, more recent web-based experiments have used the Delphi method as a communication technique for interactive decision-making and e-democracy.
Accuracy of Delphi Technique
Overall the track record of the Delphi method is mixed. There have been many cases when the method produced poor results. Still, some authors attribute this to poor application of the method and not to the weaknesses of the method itself. It must also be realized that in areas such as science and technology forecasting, the degree of uncertainty is so great that exact and always correct predictions are impossible, so a high degree of error is to be expected.
Another particular weakness of the Delphi method is that future developments are not always predicted correctly by consensus of experts. The issue of ignorance is important. If panelists are misinformed about a topic, the use of Delphi may only add confidence to their ignorance.Agile Decision Making
Agile is a time boxed, iterative approach to software delivery that builds software incrementally from the start of the project, instead of trying to deliver it all at once near the end. It works by breaking projects down into little bits of user functionality called user stories, prioritizing them, and then continuously delivering them in short two week cycles called iterations.
