Work Breakdown Structure (WBS)
DE: Projektstrukturplan (PSP)
A hierarchical decomposition of the total scope of work.
Detailed Explanation
The WBS is a hierarchical decomposition of the total scope of work to be carried out by the project team. It organizes and defines the total scope and represents the work specified in the approved scope statement. Each descending level represents increasingly detailed work.
The WBS is deliverable-oriented (not activity-oriented). It answers 'what needs to be produced' not 'what activities need to be done.' Activities are defined later during schedule planning. The lowest level of the WBS is work packages, which are the basis for cost and duration estimation.
The WBS is arguably the most important planning artifact in project management. It provides the structure for cost estimation, resource allocation, risk identification, and schedule development. The 100% rule requires that the WBS captures all project work, including project management.
Key Points
- Hierarchical decomposition of total project scope
- Deliverable-oriented, not activity-oriented
- Lowest level = work packages (estimable units)
- 100% rule: must capture all project scope
- Foundation for cost, schedule, and resource planning
- Created through decomposition technique
Practical Example
An office building WBS: Level 1 = Office Building; Level 2 = Site Work, Foundation, Structure, Exterior, Interior, Systems; Level 3 under Systems = Electrical, HVAC, Plumbing, Fire Protection, IT Infrastructure. Each Level 3 item is further decomposed into work packages sized for estimation and assignment.
Tips for Learning and Applying
Create the WBS with the team, not in isolation
Use the 100% rule: every piece of project work must appear in the WBS
Keep it deliverable-oriented: 'Foundation' not 'Pour concrete'
Use the WBS Dictionary to define each element in detail
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