The Project Work Breakdown Structure is an outcome oriented analysis of the work involved in the project and defines the total scope of the project. It is a foundation document in project management because it provides the basis for planning and managing the project schedule, budget and requests for changes. The WBS is developed in the form of an inverted tree structure, organized by objectives; it looks like an organizational chart which helps the project team visualize the whole project and all its main components.
The WBS is a hierarchy of all project work, it is a vertical breakdown, moving from the project goal to the tasks or subtasks. This decomposition process allows a good level of confidence in estimating the final project schedule and budget. It shows all the work that needs to be accomplished. The WBS contains 100% of all the work in the project.
At the top level is the project ultimate goal, the second level contains the project outcomes, the third level has the project outputs, and the fourth level with activities. Depending on the size and complexity of the project, the WBS may contain a fourth level that describe the tasks.
The size and complexity of a project will determine the number of levels a WBS needs. For some projects additional levels may be included to represent intermediate objectives. Other projects may choose to structure the WBS by the geographical locations the project will work or group the objectives by the communities participating in the project.
The Work Breakdown Structure (WBS) is an important planning tool used to define a project in terms of its outputs while providing a method for breaking these deliverables into meaningful work units. The WBS allows the project manager to clearly describe the hierarchical nature of the work to be performed and establishes a foundation for other elements of the project planning documents including the project’s resource plan, budget, implementation plan, and project schedule.
With the WBS, the project manager will be able describe the outcomes of a project in a way that is clear to the project team, while at the same time capturing the order and sequence of the work necessary to produce those outputs. The WBS provides a means for carefully detailing the outputs of the project and facilitates the identification of specific the work elements, and groupings required to deliver each element.