Activity Definition involves the identification and definition of those activities that must be accomplished to achieve the objectives of a project or program. The Work Breakdown Structure (WBS) is a logical source for such descriptions. If a WBS is not available, more planning must be done in order to identify project activities clearly. Other inputs to the definition step are the program charter, scope, historical information, program constraints and assumptions, and events required.
Activity Definition is the process of “identifying the specific schedule activities that need to be performed to produce the various project deliverables” . This process identifies “the deliverables at the lowest level in the work breakdown structure” which is the level of “work packages”: Each work package is ” planned (decomposed) into smaller components called schedule activities to provide a basis for estimating, scheduling, executing, and monitoring and controlling the project work”. On the base of the work packages (defined as deepest level of WBS entries (leafs) one collects all activities (steps), which together constitute the work packages. Or shortly spoken: Activity definition is the decomposition of the work packages. During the activity definition one answers the questions, what has to be done. Other questions like “who will do the activity”, “how much time will it take”, or “when has it to be started or finished” will be answered later: “In creating (the) activity list, you focus on what is being done, not who is doing it, how long it will take, or when it is being done”
Techniques commonly used in activity definition are
- Decomposition involves the successive breakdown of program elements into smaller, more manageable components, which eventually describe the activities to be scheduled. This technique is essentially the same used in WBS development.
- A template is an activity list or WBS element from another similar program that can serve as a model for the current program and provide a starting point for defining specific activities.
- Rolling wave planning is “a form of progressive elaboration”: What has to be done in the near future and what is already clear “is planned in detail at a low level of the WBS”. But what can be realized later and what is still more or less unclear “is planned for WBS components that are at a relatively high level of the WBS”
- Expert judgment is used for answering the question which tasks have to be done for realizing a specific work package
- Planning Component is a concept by which insufficient or irrelevant definitions or information are made usable: The control account is a specific high level point in the WBS (above the work packages) by which one can communicate a high level project schedule (or cost estimate) to the management. And a planning package is a deeper WBS unit below the control account but above the work package “for planning known work content that does not have detailed schedule activities”.
The primary output of this step is the activity list, which should contain a complete description of each of the activities necessary to complete the program. This list should be linked to the WBS, which should be reviewed and revised/clarified as necessary to incorporate changes resulting from the activity definition process. Supporting details for each activity, such as constraints and assumptions, should also be developed and documented.
Activity definition results in following outputs
- The Activity List is ” a comprehensive list including all schedule activities that are planned to be performed on the project”. And it does not contain any activity which is not necessary for realizing the project scope.
- The Activity Attributes are detailed specifications of the activities: you may think the activity list as a list of naming identifiers. And the meaning of each of these naming identifiers is the description of the connected attributes, likes predecessors, successors, durance, leads and lags and so on.
- The Milestone List contains all mandatory milestone (“required by the contract”) and optional milestones (“based upon project requirements or historical information”). The Milestone list is part of the project management plan and its content is used in the schedule model.
- And Requested Changes may appear during the decomposition of work packages into sets of activities: by the way one can discover, that scope and WBS and activities still don’t match and that one has to refine the project management plan.