The Technique for Rolling Wave Planning in Projects

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Planning can be a very frustrating task for a Project Manager. We are often asked to provide detailed estimates based on a set of activities that are not clearly defined. The Project Management Institute recommends a technique called Rolling Wave Planning which seems to apply in these situations. According to the Guide to the Project Management Body of Knowledge (PMBOK® Guide), Rolling Wave Planning is “an iterative planning technique in which the work to be accomplished in the near term is planned in detail, while work further in the future is planned at a higher level”. This suggests that we have a clear picture of the overall project, but are delaying detailed planning on distant Work Packages to get the project up and running quicker.

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Planning Challenges: Uncertain Variables and Requirements

However, a more typical reason for postponing detailed planning is because we simply do not know what is going to happen down the line. Take, for instance, a house building project. The first Work Package is the purchase of some land. We may have a preference for a certain area, but we may be flexible when it comes to an actual site. Where the house will be built will depend on which site we purchase. The choice of site can have a profound bearing on the type of house we build. The price of the site will have consequences for how much money will be available for construction. The type of soil and the shape of the site will have consequences for the foundation types and the cost of bringing services to the new building.

Managing Phases as Separate Projects

Once the site is secured, we need to obtain planning permission. We cannot apply unless we know what we are applying for. So we need to do some architecture work to explain what we want to erect on the site. However, we would not want to invest in detailed plans at this point, because the planning authorities might shoot down our application and mandate a different type of structure entirely. It is only when planning permission is granted that we can plan the construction work in detail.

Software developers find themselves in the same situation. Novel features are requested for a product, but the developers are not entirely sure how to implement them. The only way to produce a realistic estimate is to do the work first, which tends to defeat the purpose of planning. Iterative and incremental project management techniques, such as Scrum, use control theory to inform the planning process through feedback loops. This helps address another problem with software: our customers often are not sure exactly what they want. By doing small increments of work at a time, the project can be guided in the right direction through feedback. By analysing how the work is being done, the estimation process can be improved across the iterations.

Adaptive Life Cycle for Uncertain Projects

Even more profound planning obstacles occur when funding is uncertain. Many research projects depend on winning a grant. Researchers might apply for funding from different sources. Depending on the amount of money obtained in this fashion, a plan can be developed. However, if the monies obtained fall short of the required amounts, the project may go ahead, in the hope that a further round of grant applications will be successful. In many cases, a successful first phase of a project can encourage funding bodies to revise their opinions and come up with the cash needed to finish the work.

Situations like these – where the project’s viability and scope cannot be pre-determined – suggest that managing the different phases of the work as different projects – probably in a program framework – could be the way to go. It can take ages to locate a suitable building site, so there is no point in assembling a construction crew at this point. Similarly, there is no point doing detailed risk identification, because the only risk we face is not finding a site.

Of the three examples given above, the house building one is the only one that could be considered a candidate for Rolling Wave project planning. This is because the overall Work Breakdown Structure will be the same, no matter what the variables are. The location of the site and the restrictions of the planning authorities will influence the details of the construction work, but the foundations will still have to be laid; services will have to be brought to the site; walls built and a roof put on. We can plan in outline, but not in detail.

In the case of the software product, we often suffer from uncertainty in our requirements and the iterative approaches allow a mutual understanding of what the product should be to build up. Because of this initial uncertainty, we cannot plan in detail. Indeed our end product may bear no resemblance to any original concept. Similarly, the example research project may end up completely different from the initial concept. In both cases, a definitive outline Work Breakdown Structure cannot be established at the start. The way the Project Manager copes in these circumstances could not be described as Rolling Wave planning. Instead we should use another PMBOK® Guide term: the “Adaptive Life Cycle”.

Velopi’s project management training courses cover Project Schedule Management, where all aspects of scheduling are covered. If this area is of interest to you, our project management professional certification courses are held online in our virtual classroom for your convenience. Find out more by visiting our training page or by contacting us directly.

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