Applied Software Project Management

Wideband Delphi Estimation

The Wideband Delphi estimation method was developed in the 1940s at the Rand Corporation as a forecasting tool. It has since been adapted across many industries to estimate many kinds of tasks, ranging from statistical data collection results to sales and marketing forecasts. It has proven to be a very effective estimation tool, and it lends itself well to software projects.^[*]

The Wideband Delphi estimation process is especially useful to a project manager because it produces several important elements of the project plan. The most important product is the set of estimates upon which the project schedule is built. In addition, the project team creates a work breakdown structure (WBS), which is a critical element of the plan. The team also generates a list of assumptions, which can be added to the vision and scope document.

The discussion among the team during both the kickoff meeting and the estimation session is another important product of the Delphi process. This discussion typically uncovers many important (but previously unrecognized) project priorities, assumptions, and tasks. The team is much more familiar with the work they are about to undertake after they complete the Wideband Delphi process.

Wideband Delphi works because it requires the entire team to correct one another in a way that helps avoid errors and poor estimation. While software estimation is certainly a skill that improves with experience, the most common problem with estimates is simply ...