What is a WBS?
A WBS is a hierarchical decomposition of the deliverables needed to complete a project. It breaks the deliverables down into manageable work packages that can be scheduled, costed and have resources assigned to them. As a rule, the lowest level should be two-week work packages. Another rule commonly used when creating a WBS is the 8/80 rule. This says no single activity should be less than 8 hours, or greater than 80 hours.