The Work Breakdown Structure (WBS) is a view of the entire scope of a project broken down into smaller work blocks, in a hierarchical structure. The completion of the work blocks will result in the completion of the deliverable, and achievement of the objectives. It is imperative that 100% of the needed work will appear in the WBS diagram, and that there is not any overlap between different work blocks. The WBS is not a project plan: It specifies who does what, not when, or how.
The WBS Dictionary expands the WBS further by providing information about:
- Description of the task.
- The person is responsible for delivering that task.
- Resources required to complete the task.
- Acceptance criteria that will be used for sign-off.
- Constraints regarding time, cost, and others (e.g., quality)