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The Delphi Process
To use Wideband Delphi, the project manager selects a moderator and an estimation team
with three to seven members. The Delphi process consists of two meetings run by the
moderator. The first meeting is the kickoff meeting, during which the estimation team cre-
ates a WBS and discusses assumptions. After the meeting, each team member creates an
effort estimate for each task. The second meeting is the estimation session, in which the
team revises the estimates as a group and achieves consensus. After the estimation session,
the project manager summarizes the results and reviews them with the team, at which
point they are ready to be used as the basis for planning the software project. The script in
Table 3-1 describes the Wideband Delphi process.

TABLE 3-1. Wideband Delphi script
Name Wideband Delphi script
Purpose A project team generates estimates and a work breakdown structure.
Summary A repeatable process for estimation. Using it, a project team can generate a consensus on esti-
mates for the completion of the project.
Work Products Input
Vision and scope document, or other documentation that defines the scope of the work
product being estimated
Output
Work breakdown structure (WBS)
Effort estimates for each of the tasks in the WBS
Entry Criteria The following criteria should be met in order for the Delphi process to be effective:
• The vision and scope document (or other documentation that defines the scope of the
work product being estimated) has been agreed to by the stakeholders, users, managers,
and engineering team. If no vision and scope document is available, there must be enough
supporting documentation for the team to understand the work product.
• The kickoff meeting and estimation session have been scheduled (each at least two hours).
• The project manager and the moderator agree on the goal of the estimation session by
identifying the scope of the work to be estimated.
Basic Course of Events 1. Choosing the team. The project manager selects the estimation team and a moderator. The
team should consist of three to seven project team members. The team should include
representatives from every engineering group that will be involved in the development of
the work product being estimated.

2. Kickoff meeting. The moderator prepares the team and leads a discussion to brainstorm
assumptions, generate a WBS, and decide on the units of estimation.
3. Individual preparation. After the kickoff meeting, each team member individually gener-
ates the initial estimates for each task in the WBS, documenting any changes to the WBS
and missing assumptions.
4. Estimation session. The moderator leads the team through a series of iterative steps to gain
consensus on the estimates. At the start of the iteration, the moderator charts the estimates
on the whiteboard so the estimators can see the range of estimates. The team resolves
issues and revises estimates without revealing specific numbers. The cycle repeats until
either no estimator wants to change his or her estimate, the estimators agree that the range
is acceptable, or two hours have elapsed.
5. Assembling tasks. The project manager works with the team to collect the estimates from
the team members at the end of the meeting and compiles the final task list, estimates, and
assumptions.
6. Reviewing results. The project manager reviews the final task list with the estimation team.

40 CHAPTER THREE