A work breakdown structure (WBS) is a deliverable-based breakdown of a project into progressively smaller components. It defines and groups the project’s discrete elements of work in a way that organises and defines the total scope of the project.
A WBS is usually shown as a hierarchy, with the whole project at the top, dividing down through stages, packages or elements to individual work packages that can be planned, priced and managed. It gives the programme, cost plan, procurement packages and cost reports a common structure, so cost and progress are tracked under the same headings. For the quantity surveyor, a well-structured WBS makes it easier to:
- align the budget with the programme
- allocate and monitor costs by package
- report progress, earned value and value of work done
The WBS should cover the whole scope with no overlaps, so that nothing is missed or counted twice.
Related terms: cost breakdown structure, work package, programme, earned value.
