The WBS:
- Serves as the project scope baseline
- Is one of the most important project management tools
- Serves as the foundation for planning, estimating, and project control
- Visualizes the entire project
- Notes that work NOT included in the WBS is NOT part of the project
- Builds team buy-in to the project
- Serves as a control mechanism to keep the project on schedule
- Allows for more accurate cost and time estimates
- Serves as deterrent to scope creep
WBS should not be confused with:
- Organizational breakdown structure
- Bill of Materials
- Risk breakdown structure
- Resource breakdown structure
This tool is related to planning and scheduling a project. Basically it is a functional decomposition of the tasks of the project. The total work of the project is broken down into the major subtasks. It starts with the end objective required and successively subdividing it into manageable components in terms of size and complexity: program, project, system, subsystem, components, tasks, subtasks, and work elements.
WBS Dictionary
If a WBS is extensive and if the category content is not obvious to the project team members, it may be useful to write a WBS dictionary. The WBS dictionary describes what is in each WBS element, and it may also say what is not in an element, if that is unclear. Here is a sample of a WBS dictionary description:
Benefits of using a WBS
- Builds the project team
- Provides a framework to identify projects separately from organizations, accounting systems, funding sources, and so on
- Clarifies responsibilities
- Focuses attention on project objectives
- Forces detailed planning and documentation
- Identifies specific work packages for estimating and assigning work
The work breakdown structure (WBS) is a central point of the project planning effort. No realistic overall project plan is possible without first developing a WBS that is detailed enough to provide meaningful identification of all project tasks that must be accomplished. The process of creating the WBS is very important, because during the process of breaking down the project, the project manager, the staff, and all involved functional managers are forced to think through all aspects of the project.
A WBS is a technique for breaking down a project into its component elements. The smallest tasks, called Work Packages, must be identified as manageable units that can be planned, budgeted, scheduled, and controlled. The WBS indicates the relationship of the organizational structure to the project objectives and tasks, and so provides a firm basis for planning and controlling the project.
The WBS should be product or task-oriented and should include all the necessary effort, which must be undertaken to achieve the end objective. Because it defines the work required to achieve an objective and help to show the required interfaces, a WBS is useful for complex projects. However, it has got an important drawback: it does not show the timing of activities. In order to overcome this drawback, another tool will be used.
Note: Most importantly, you should know that a work breakdown structure is a decomposition of the project work that has to be done. Know the benefits and be familiar with the fact that the WBS contributes to customer communication.
