Work Breakdown Structure

Work Breakdown Structure (WBS) is the most important project management tool. WBS captures the entire project scope of work in a very objective fashion. A well designed WBS guides the project team to do project planning, project execution and project control effectively.
WBS is a hierarchical decomposition of project work into smaller and more manageable components.

Usage of WBS:

• Planning and budgeting 
• Scheduling  
• Estimating costs
• Analysing cost drivers
• Identifying risks
• Making resource assignments
• Measuring and controlling performance
• Configuration management (work added or deleted)
• Communicating with the customer and other key stakeholders (especially about scope)
• Does NOT describe work at the smallest sub-tasks

Big project work is systematically decomposed into smaller and more manageable components. The WBS looks like a tree structure. The decomposition of major components of project continues till the level where the project team and SMEs feel that work at that level can be managed well.

Work items at the lowest level of WBS are called as a Work Package. A Work Package can be accurately scheduled and cost estimated, unambiguously allocated, properly tracked and monitored. Although there is no rule as to how big a work package should be, but there are some thumb rules which suggest that work packages should be just big enough to be completed in a single review period. i.e. 80 hours.

The details of work packages are captured in a separate document called WBS Dictionary. WBS can be depicted in either a graphical format or in an indented fashion. Both have their unique usage. While a graphical format WBS is very useful for discussion with stakeholders, an indented WBS is very useful to discuss with team members.

All work packages which are part of the project, must be captured and included in the WBS. Anything which is there in WBS is part of scope of work and anything which is not there in WBS is not part of project scope of work.

How to develop a Work Breakdown Structure

Making a WBS is a team effort. The core team members of the project will follow the below steps in making a WBS.

1. Identify the major components of the project. The major components will be shown as the level 2 items of the WBS.
2. The project can be visualized as consisting of major functions, or phases or deliverables in the 2nd level.
3. Each major component from 2nd level will further be decomposed by the team to smaller and more manageable components.
4. The team continues to decompose until they identify the work packages. A work package is the smallest deliverable, which further cannot be decomposed as deliverables.
5. Carefully identified work packages will form the basis for understanding the entire project work in sufficient detail.
6. Work packages will be used for estimating the duration, resource and cost for each of them.
7. During decomposition, the team can use their past experience or the template of a WBS from a similar project they would have done.
8. A code of account is used to assign a unique code to each element in the WBS. The unique code is used for tracking the status. The code of each work element can be mapped to the organization’s accounting system for tracking project expenditure.
9. Making a WBS requires creative thinking and immense experience to make it meaningful and useful.
10. Over decomposition of work may lead to unnecessary wasted management efforts.

Conclusion

The WBS is the most fundamental artefact of a project. It captures the entire scope of the project as a set of well-defined work packages. Work packages make it easier for making more accurate estimations, effective monitoring, and responsibility assignments. PMP course is the best way to learn about WBS.