Unless the entire delivery schedule is three months or less, a project plan with only four milestones doesn't provide adequate opportunity to manage and control a project. Therefore, interim milestones are established, which each team lead makes a commitment to achieve. This makes issues visible to the management team at scheduled review and coordination points, and Program Management can assess impact on the overall delivery schedule.
Examples of externally visible interim milestones — those announced to the organization at large — include:
Regularly-scheduled management review meetings. Those attending the meetings should assess status and review change requests (formal or informal) against the deliverables.
Availability of a draft functional specification. The functional specification should include interim delivery of information models and user task analysis. The specification should be reviewed and validated with the customer.
Post-functional specification baseline meetings. Those attending the meetings should approve freeze points such as visual freeze, database freeze, and functional freeze.
Examples of interim milestones internal to the development team include:
Short-term internal deliverables. These deliverables should be in five- to ten-day increments so that a realistic assessment of progress and risk can be made.
Synchronization points. These ensure that elements of the functional specification are consistent and driven from the same set of assumptions. These points should be defined by Program Management and include the discussion of the data model, business model, user interface, and systems architecture.
Incremental internal releases. These releases are determined by Development, at a maximum of six-month intervals (three-month deliverables are recommended).