Rolling Wave Planning: Progressive Schedule Development

PMBOK v8 Definition

Rolling wave planning is a technique that involves preparing detailed schedules progressively as projects unfold, initially outlining broad milestones and key activities, then refining and expanding upon them as more information becomes available or as the project progresses. This approach allows for flexibility and adjustment as the project evolves and more details become known. It is an iterative planning technique where work to be accomplished in the near term is planned in detail, while work in the future is planned at a higher level.

Why It Matters for the Exam

Rolling wave planning appears frequently on the PMI exam in questions about schedule development approaches, particularly when testing your understanding of progressive elaboration and adaptive planning methods. You will encounter it in situational questions where the project lacks complete upfront information, requiring you to select the appropriate technique for phased or iterative schedule development.

Key Points to Remember (for the exam)

• Definition Core: Rolling wave planning is progressive elaboration applied to the schedule—near-term work is detailed, future work is high-level
• Primary Context: Used when there is insufficient time to analyze project details upfront, or when details are still evolving
• Applicable Approaches: Works for both predictive and adaptive projects; even predictive projects may need this technique
• Key Output: A project schedule that includes linked activities with planned dates, durations, milestones, and resources
• Common Confusion: Rolling wave planning is NOT the same as the entire project being undefined; it is deliberate progressive detailing of known work
• Relationship to WBS: The project team waits until the deliverable or subcomponent is agreed on before developing WBS details
• Schedule Levels: Schedule levels can change depending on the approach (adaptive or predictive), practitioner, and organizational scheduling requirements

Typical PMI Exam Example

You are managing a construction project with a 24-month timeline. The client has approved the first 6 months of detailed design work but has not yet finalized specifications for the remaining phases. Which technique should you use to develop the schedule?

Answer: Rolling wave planning—detail the first 6 months of activities while keeping the remaining 18 months at a milestone level, then progressively elaborate as specifications become available.

PMI Exam Traps

• Trap: Believing rolling wave planning is only for adaptive (agile) projects

  • Reality: PMBOK v8 explicitly states it is used even in predictive approaches when details are evolving

• Trap: Confusing rolling wave planning with "no planning at all"

  • Reality: It requires initial broad milestones and key activities defined upfront, then progressive refinement

• Trap: Thinking rolling wave planning replaces the need for a schedule model

  • Reality: The project schedule is an output of a schedule model that presents linked activities with planned dates, durations, milestones, and resources

• Trap: Assuming rolling wave planning is a one-time activity

  • Reality: It is an ongoing, iterative process; planning can follow a progressive, iterative, or rolling wave approach according to the project phase or life cycle approach

Important PMI Connections

Quick Review Questions

1. A project manager is developing the schedule for a 12-month IT implementation. The requirements for the first 3 months are fully known, but later phases depend on vendor selection outcomes. Which technique should be used?

2. What is the difference between rolling wave planning and developing the entire project schedule in detail upfront?

3. In which type of project approach (predictive, adaptive, or both) can rolling wave planning be applied?

4. What must be defined before the WBS details can be developed using rolling wave planning?

5. How does rolling wave planning relate to progressive elaboration?

PMBOK v8 Reference

Section 2.6 - Schedule Performance Domain (context of progressive schedule preparation) Section on Rolling Wave Planning (technique description and application) Section on Work Breakdown Structures (relationship between rolling wave planning and WBS development)

Note: This article is based exclusively on the PMBOK v8 context provided. Rolling wave planning is a tested concept that requires understanding its application across different project life cycles and its relationship to progressive elaboration and WBS development.