Rolling wave planning is a project management technique that involves progressive elaboration to add detail to the Work Breakdown Structure (WBS) on an ongoing basis. At the beginning of the project, near term deliverable are decomposed into individual components (work packages) and defined at the greatest level of detail. Deliverable and schedule activities that will take place several reporting periods in the future are more broadly defined. For example, Phases 1-2 might be broken down fully in the WBS. Phases 3-6 might be outlined only to the level of sub-projects. Then, while schedule activities for phase 1 are underway, the detailed planning for phase 3 would commence. As phase 2 is put in motion, planning for phase 4 would start and so forth.

In this way, rolling wave planning permits work activities to move forward on current and near term deliverable while planning is still ongoing for future work packages. This type of project management approach is particularly useful when the availability of information needed to plan future work packages in detail is predicated on the successful completion of previous project phases. This technique may also help shorten time to completion in 2 ways:

1. By making it possible for productive activities to begin without waiting for every detail of the project work to be determined in advance
2. By eliminating downtime for additional planning in the middle of a project since planning is done continuously

Project management that is undertaken using rolling wave planning must have a well-defined project scope from the outset. Otherwise, as planning is elaborated scope creep is likely to occur.