Developing the project work breakdown structure – 33R-15
Work Breakdown Structure (WBS) is the foundation on which projects are planned and tracked. The scope of work of the project is decomposed into smaller units of work, known as work packages. Without a proper WBS, an accurate estimate of the project work is impossible. The recommended practice ‘Developing the project work breakdown structure -33R-15 ‘ explains the concepts of developing and maintaining work breakdown structures which are accurate enough.
- Design principles
1.1 )100% rule – There should be one to one mapping between the project scope and the work breakdown structure. If any scope is missed out in the WBS, most probably the final product will be without it. WBS must be updated to include revisions for authorized changes and modifications throughout the project’s life cycle.
1.2 ) Mutual exclusivity – There should not be redundancy of scope across work packages
1.3) Outcome driven – WBS is a deliverable oriented grouping of work
1.4) 8-80 rule – 8-80 rile suggests that work packages should not be lesser then 8 hours of work and greater than 80 hours of work. Decomposing the work packages to a level lower than 8 hours will result in micro management, where as it is difficult to track work packages which are more than 10 days (80 hours) and will reduce visibility of the project progress.
1.5) Activity duration lesser than the reporting period – The activity durations must be lesser than the reporting period, else earned value measurement will be difficult.
1.6) Three levels minimum – The scope of work must be decomposed to a minimum of three levels
1.7) Decomposition – The process of decomposing the scope of work into work packages is the first level of decomposition. Decomposing the work packages into activities, prior to schedule development is the next level of decomposition.
1.8) Tree / List – Work break Down Structures (WBS), can be in the tree form or it can be in the form of a list.
1.9 ) Collaborative effort – Scope decomposition and WBS development is a collaborative effort by the project team that may include the project manager, project control personnel, technical, and other stakeholders
1.10) The two components of the WBS –
Levels – These establish the hierarchical structure of the work breakdown structure. Typically the highest level of the WBS is identified as level 0 or level 1
Elements – A discrete member of the WBS at each level of the hierarchy. It may be referred to as a node. At this level it represents the scope of work or task to be performed.
1.11) WBS dictionary – Additional information about the work packages like description of work, expected deliverables, constraints, assumptions, quality standards to be followed, successor, predecessor etc.
1.12) Standardization – Repeatable or similar projects can benefit by WBS standardization.
1.13) Base lining and scope control – Once the WBS and associated dictionary are developed and approved, they should be placed under revision control.
1.14) Cost mapping – All costs and resources for a project should be mapped to a WBS element
2. Coding scheme – Having standards for coding WBS makes the analysis easier
3 ) References
3.1) Developing the project work breakdown structure – 33R-15
3.2) TCM framework
3.2.1) Project scope and execution strategy development
3.2.2) Project control plan implementation
4) Two types of breakdown structures
4.1) Contract work breakdown structure – A work breakdown structure of the products or services to be furnished under contract.
4.2) Project work breakdown structure – A summary WBS tailored by project management to the specific project with the addition of the elements unique to the project. Also called the WBS
5) Root cause analysis for poor WBS – No written guideline available for developing and maintaining quality WBS