The document discusses work breakdown structures (WBS), which break down project tasks into hierarchical packages. A WBS splits tasks into logical packages that can be cost controlled and reported on. The lowest level of a WBS should be individual tasks that a single person can complete within a reasonable time period. However, a WBS does not show task dependencies, durations, or resources. Alternatives to a WBS include a product breakdown structure, which breaks down project components, and a cost breakdown structure, which identifies cost categories and should be done after the WBS and PBS.