Rolling-wave planning

Rolling-wave planning is the process of project planning in waves as the project proceeds and later details become clearer; similar to the techniques used in agile software development approaches like Scrum..[1]

Work to be done in the near term is based on high-level assumptions; also, high-level milestones are set. As the project progresses, the risks, assumptions, and milestones originally identified become more defined and reliable. One would use rolling-wave planning in an instance where there is an extremely tight schedule or timeline to adhere to; whereas more thorough planning would have placed the schedule into an unacceptable negative schedule variance.

The concepts of rolling-wave planning and progressive elaboration are techniques covered in the Project Management Body of Knowledge [2].