Thursday, April 13, 2017

Evolving Planning: The Rolling Wave Approach for Project Planning

Planning is a decision-making process whereby interdependent decisions are integrated into a system of decisions. What makes effective planning particularly challenging is that it entails an anticipatory process, as decisions are made on future actions and how to perform them. However, in today’s dynamic environment, characterized by frequent unexpected events and volatile information, anticipation becomes very difficult, and the key question faced by the project team is how far in advance of implementation they should make their decisions. Making them early provides more time to develop and coordinate these decisions with other interrelated decisions, and in general, to be better prepared for implementation. However, if decisions are made too early, there is a high probability that the changes that will take place between the time of decision making and the time of implementation will require that the decisions be modified. 

To cope with these conflicting considerations, project managers employ a “rolling wave” approach to planning. Thus, they develop plans in waves as the project unfolds and information becomes more reliable. They help develop Action Plans, which are detailed short-term plans with a one-to-two-week time horizon, usually the responsibility of low-level supervisors. Medium-term plans (e.g., 90-day Look-Ahead Plans) are less detailed in comparison, typically with a time horizon of two to six months. Being at the hub of internal and external project information, the project manager is in the best position to lead the periodic updating of the medium-term plans. Finally, long-term plans (Master Plans), cover the duration of the entire project and are quite general, presenting only aggregate activities. Through the rolling wave approach, project managers can ensure short-term stability and long-term flexibility (see Figure 1). 

 Fig. 1: Influence of planning horizon on degree of detail

This style of planning does not imply that decisions should be arbitrarily “put off until later.” Rather, it is an act of deliberately splitting off those planning aspects that can be acted upon more opportunely in the future. By applying this approach, two extreme situations are avoided. The first is the preparation of overly detailed plans too soon, which may lead to rapid obsolescence because some decisions are based on information provided by intelligent guesses rather than on reliable data. This is particularly the case when the project suffers from a high degree of uncertainty. The other extreme situation is delaying the planning until all the information is complete and stable. In both cases, project effectiveness will suffer. 

The benefits of this planning approach go beyond offering stable plans. When adopting this planning method, the preparation of plan updates shifts from the full time professional scheduler, who remains responsible primarily for the Master Plan, to the project manager and his/her team who now may assume responsibility for the short-term Action Plans, as well as for the mid-term plans. This approach may enhance the involvement of the entire team in the project planning process, creating a sense of ownership and promoting greater responsiveness to change.

Ray Morgan, the project manager of Pathfinder, a solar-powered airplane, used the short- and mid-term schedule as a means not only for communicating the overall picture of what needed to be done, when, and why; but also for actively engaging the entire team in updating and using their plans. He, therefore, put a graphic depiction of the schedule on the side of a large container right in the hangar, next to the flight test crew and the airplane. The team was encouraged not simply to adhere to the original plan but to add and delete tasks interactively. These changes were incorporated into a computer model and were reprinted once or twice a week during flight tests. The team often referred back to the chart to help redefine the importance of a current task and to see how it fit into “the big picture.” Thus, the plans resulting from the on-going learning was owned by the team.