A work breakdown structure (WBS) is delieverable-oriented groupingof project element that organizes and defines the total scope of the project. Each descending level within the WBS represents an increasingly detailed definition of the project work. The WBS is an output scope planning and scope definition stages of the project planning effort.

The WBS describes the work of the project in terms of four first-level deliverables within Plan & Initiation, Design, Construction, and Commission & Evaluate. These four primary WBS deliverables are further described by a series of sub deliverables. The items at the lowest level of the WBS (i.e. Risk Management Plan) constitue work packages. The actual WBS work breakdown document will be developed in consultation with all project stakeholders to ensure that it is an inclusive statement of the deliverables of the project.