Work Breakdown Structure. In project management terminology, the WBS is a detailed schedule of the project that shows the tasks and sub-tasks and the related timelines that each task will be completed in. Each activity in a WBS will have a start date and end date, and further, they may be constrained to not start before or end after a specific date. In addition, each task may be dependant on the previous task and linked to the task that follows. If the start or end dates for any task changes, then correspondingly, the start and end dates of all tasks linked to this task will change.