The resources of an organization consist of people, materials, equipment, knowledge and time. Organizations typically have limited resources; therefore, tradeoffs on what project resources are expended and when are made every day within organizations. A resource allocation plan is an important tool in effective management of scarce resources.
The timing of the need of those resources can be and should the within the project schedules. A resource plan, which describes the type of resource needed and the timing of that need, is critical to effective resource management. As the project schedule changes, the resource plan must also be flexible enough to adjust as these changes occur.
Dealing with unknowns
In developing resource plans, there is little chance that the project manager will have all of the necessary resources assigned to the project at its start. The fact is when starting a project the details of that project are typically unknown. Therefore, knowing the types and duration of resources necessary is not always possible.
Known knowns are events that can be planned for. In building the schedule, some deliverables can be decomposed in sufficient detail creating tasks, while other deliverables will only be known at the highest level. When details of a deliverable are not sufficiently known, a planning package should be used.
The details of the deliverables defined within planning packages can be considered known unknowns, or risks. In these instances, the work has not been fully decomposed.
Known planning events, as well as planning packages, can be assigned individual resources and durations that have been established by the people who will be doing the work. The only difference is in planning packages, the duration and resource estimates are typically less accurate. The use of historical information or industry standards can provide a higher degree of confidence in estimates, when available.
It is not necessary to have all deliverables decomposed and assigned to individuals prior to beginning work on a project. In fact, it is very common to set a baseline schedule and resource plan based on planning package estimates.
As the project progresses, these known unknowns become clearer to the project team warranting changes within the project schedule and resource plan.
Events that cannot be planned for are called unknown unknowns. These events are not known in the realm of possibilities, yet could occur. An example is a warehouse fire that destroys inventory and delays the project completion. This would not normally be factored in as a known event during the project planning, so it is an unknown unknown.
Since projects are unique and temporary endeavors, project managers will always work in a world of unknowns. Therefore, resource management and planning should continue throughout the project life cycle.