Work Breakdown Structure

The Work Breakdown Structure (WBS) shows the total project divided into components that can be measured in terms of time and cost. It may be presented in tabular or graphical form or both. Whether in tabular or graphical form, the WBS divides the project into a series of hierarchical levels; in the graphical form, it resembles an organisational chart of tasks (rather than positions). The complexity of the project and the degree of control desired during the project monitoring will determine the number of levels. We suggest starting with three levels, with level one being the final or total project, level two being the major tasks or subsections of the project, and level three containing definable tasks or sub-components of level two. Again, if the project is very complex, the WBS should include additional levels, until the final level specifies discrete activities that can be examined in terms of the time and cost required to complete the activity.

At the final level, the Work Breakdown Structure should include at least two pieces of information that are needed for the coordination of effort: the estimated time to complete the activity and the name of an individual who is responsible for seeing that the activity is completed. Often a third piece of information, the estimated cost of completing the activity, is also included. This allows for better integration of cost and schedule information needed to complete the monitoring of the project. When cost information is included, people refer to the Work Breakdown Schedule as a costed WBS. It should be noted that time and cost estimates should be developed by the persons most knowledgeable about those specific activities. Thus, if project team members come from different functional areas, the project manager should consult with managers from those different functional areas before making time and cost estimates.