When developing the WBS, the 100% Rule applies, which states that the work at the lowest levels of the WBS must add up to 100% of the work to be completed.
In the Create WBS process (Work Breakdown Structure), you subdivide project deliverables and project work into smaller, more manageable components, the smallest of which is the Work Package. The final result is a structured vision of what has to be delivered.
The WBS ensures that no project work is overlooked, but it is o.k. to defer the decomposition of WBS components far into the future until sufficient details become apparent (Rolling Wave Planning).
In general, deliverables are decomposed into 8 to 80 hour Work Packages.
Inputs of Create WBS are:
- Project Management Plan (Scope Management Plan)
- Project Documents (Project Scope Statement, Requirements Documentation)
- Tools and Techniques are:
- Expert Judgement
- Decomposition
Outputs of Create WBS are:
- Scope Baseline
- Project Documents Updates (Assumption Log, Requirements Documentation)
The Scope Baseline identifies all the deliverables from which you derive the type and quantity of resources required to create the deliverables. The Scope Baseline includes the approved version of the: Scope Statement, the WBS Dictionary, and the WBS.
The RACI will show responsibilities assigned to work packages defined in the WBS.