6.1.1 Inputs to Activity Definition

.1 Work breakdown structure. The work breakdown structure is the primary input to activity definition (see Section 5.3.3.1 for a more detailed discussion of the WBS).

.2 Scope statement. The project justification and the project objectives contained in the scope statement must be considered explicitly during activity definition (see Section 5.2.3.1 for a more detailed discussion of the scope statement).

.3 Historical information. Historical information (what activities were actually required on previous, similar projects) should be considered in defining project activities.

.4 Contraints. Constraints are factors that will limit the project management team’s options; an example would be use of desired maximum activity durations.

.5 Assumptions. See Section 4.1.1.5.

.6 Expert judgment. Expert judgment is discussed in Sections 5.1.2.2 and 6.3.2.1.

6.1.2 Tools and Techniques for Activity Definition

.1 Decomposition. Within the context of the process of Activivity Definition, decomposition involves subdividing project work packages into smaller, more manageable components to provide better management control. The technique of decomposition is described in more detail in Section 5.3.2.2. The major difference between decomposition here and in Scope Definition is that the final outputs here are described as activities (actions steps) rather than as deliverables (tangible items). The WBS and the activity are usually developed sequentially, with the WBS being the basis for development of the final activity list. In some application areas, the WBS and the activity list are developed concurrently.

.2 Templates. An activity list (described in Section 6.1.3.1), or a portion of an activity list from a previous project, is often usable as a template for a new project. The activities in templates can also contain a list of recourse skills and their required hours of effort, idenftification of risks, expected deliverables, and other descriptive information.

6.1.3 Outputs from Activity Definition

.1 Activity list. The activity list must include all activities which will be performed on the project. It should be organized as an extension to the WBS to help ensure that it is complete and that it does not include any activities that are not required as part of the project scope. As with the WBS, the activity list should include descriptions of each activity to ensure that the project team members will understand how the work is to be done.

.2 Supporting detail. Supporting detail for the activity list should be documented and organized as needed to facilitate its use by other project management processes. Supporting detail should always include documentation of all identified assumptions and constraints. The amount of additional detail varies by application area.

.3 Work breakdown structure updates. In using the WBS to identify which activities are needed, the project team may identify missing deliverables or may determine that the deliverable descriptions need to be clarified or corrected. Any such updates must be reflected in the WBS and related documentation, such as cost estimates. These updates are often called refinements and are most likely when the project involves new or unproven technology.