WBS Explained

WBS stands for “Work Breakdown Structure”. Simply put, it delineates the work required to complete the project. A WBS makes a Project Managers life easier, and it ensures a complete understanding of the work required to complete the task at hand. A WBS is the delineation of the scope into work packages and activities required to complete successfully. It represents total project scope as well as product scope.

I have witnessed during my time as a Project Manager many a practicing project manager not using the WBS correctly or at all. Many find it burdensome; others think it’s useless, and others just do not understand how it. What’s worse is when management sees no value in the exercise of putting a WBS together.

A WBS is easy to understand and quite easy to create. It has immense effectiveness serving as an anchor for many a successful completed project. There are numerous publications that can guide you in developing a WBS. I will focus on the importance of a WBS to the project and some detail on writing one.

A WBS takes time, thought, and collaboration. It should have a method for identifying the hierarchy in either a hierarchical chart or as an outline. It should include a WBS Dictionary that explains in detail how to complete each package/activity. The dictionary spells out the expectation of the deliverable.

  • A WBS can receive information from:
    • The scope management plan
    • The scope statement
    • The requirements document
  • The WBS is related to:
    • WBS dictionary
    • Scope baseline
  • It provides information to
    • Activity list
    • Activity cost estimates
    • Project budget
    • Risk register
    • Accepted deliverables

What is the difference between a deliverable and activity?
A deliverable is the result or outcome of series of activities. The activity represents a small portion of the total work package and deliverable.

Why is WBS important?

  1. WBS is a hierarchical representation of the scope of a project; it represents the total scope of work required.
    • A WBS represents the total scope and hence it can act as a checklist for the project.
  2. A Project Manager can easily see the completed work and what is work remains in the project.
    • The deliverable represented by the WBS is easily monitored and tracked.
    • Each successive level of WBS provides a basis for more precise estimation of remaining effort, duration, resources and cost in which to complete the project.
  3. A WBS can serve as a template for future similar projects – specifically for repetitive processes thus making future projects easier and faster to plan.
  4. Activities are easily assigned to team members making accountability easier.

A WBS can reduce project risk.


  1. A WBS uses nouns and adjectives to define work.
  2. The key is that we are talking about the nouns, the (mostly) tangible objects created through project work.
  3. Always put deliverables in the first couple of levels
  4. Only move from deliverables to tasks when you’ve pushed down several levels, and have gotten to packages that are reasonably small and estimable.
  5. The tasks to be performed are always in support of a deliverable.