An Introduction To Rolling Wave Planning

This method of planning is used on evolving projects where complete information is not available. When requirements are vague or the key activities that need to be executed are not clear upfront, the rolling wave planning technique can come in handy. 

Sometimes, you may need to make a plan and then begin the implementation of the plan before you see the full picture of exactly what it entails. It is similar to agile planning and involves an iterative approach where you plan until you have visibility, execute the plan and then re-plan with the details you have.

Rolling wave planning applies the concept of progressive elaboration, which involves elaborating on work packages as the project unfolds.  It begins with a detailed plan for activities to be executed in the near term, while activities to be executed in the future are defined at a higher level of detail. The plan contains a higher level of detail with time.