A work-breakdown structure or WBS for short is a way of breaking down a large project into separate components or elements for estimating, costing and collecting revenues. It is typically hierarchical in that the project is first broken down into major elements or components and then each of these are further decomposed. For example a project to deliver a helicopter might be broken down initially into build and after delivery support, with the build WBS further broken down into component build, sub-assembly, final assembly, fitting/interior, paint/finish and delivery/test. The basic premise or idea is to make each WBS small enough to plan - particularly in regard to duration, schedule, resources and cost. Each WBS normally comprises multiple tasks and a task does not normally span two or more WBS elements.

In iBE.net each WBS is represented as a separate project. Projects can be grouped together via various mechanisms such as tags (which can be hierarchical in nature) to construct and report costs and revenue through a WBS hierarchy. For more information refer to project cost and schedule reporting and tags.