The work breakdown structure (WBS) defines the work that is required in order to produce the product or deliverables. It is represented as a hierarchical subdivision of a project into work areas with the lowest generally being a work package or sometimes even an activity.

The lowest level of the WBS should be consistent and agreed at the outset of the creation of the WBS. The WBS provides the foundation for all project management work, including planning, cost and effort estimation, resource allocation, and scheduling.

Creating a WBS:

enables the definition of the total scope of work

provides the ability to assign work to people responsible for carrying out the work

establishes a control baseline

measures accomplishments objectively when the work is done

defines, collects and reports information at the appropriate level required

defines the relationships between work, organisation and cost.