Work breakdown structure

The work breakdown structure (WBS) and associated dictionary is a tool to provide a view (outline or map) into the project/program and the work that needs to be done to execute the project/program. The WBS is designed to break down a project/program into manageable pieces (work packages) that can be effectively estimated and owned by a single resource. It does not break the project/program down to the task level. It is deliverables based, meaning the work packages result in some type of deliverable towards the project/program's overall objectives, costs and scope.  

The project/program manager and project/program team use the WBS to develop dependencies, the schedule, resource requirements, scope, and costs.  As such, the WBS provides the foundation for all project/program management work and should be a critical step in the process of project/program planning and establishing a baseline. The WBS is a component of the scope baseline.

WBS participants and approvers

Input into the WBS may come from many different sources including, but not limited to, sponsor, senior leadership, project/program intake form and/or business case, charter, analysis/research, subject matter experts within business unit(s), and interaction with other stakeholders. The facilitator is  the project manager  (or program manager) for the project/program.  The WBS should be reviewed by the team, sponsor, business analyst, and owner for completeness and accurateness.


The project/program manager should facilitate a session with the appropriate stakeholders to map out the WBS for the project/program.  In preparation for the session, the project/program manager may have looked at the WBS from similar projects/program and documentation for this project/program to have a high-level idea of what type of work and deliverables are required.

  1. View one or two samples if this is the first time facilitating the creation of a WBS
  2. Sometimes it is easier if the project/program manager starts with some the preliminary high-level structure of the WBS and then uses the session to decompose those levels
  3. The WBS starts with the project/program as the top-level deliverable and is further decomposed into sub-deliverables. Use numeric identifiers for each work package.
  4. The decomposition process should stop when the smallest manageable components of the project/program work (work packages) are reached where cost and time can easily be estimated. General rule of thumbs is to break it down to a level where a work package contains 8 to 80 hours of effort.
  5. Review WBS with applicable stakeholders for accuracy and completeness
  6. Upload to the knowledge base
  7. Begin creation of budget, scope, and schedule

Next steps

Create budget, scope, and schedule baselines using the WBS.  Maintain the WBS throughout the project/program.