A Work Breakdown Structure (WBS) in project management and systems engineering, is a tool that defines a project and groups the project’s discrete work elements in a way that helps organize and define the total work scope of the project. [pic]
Example of a work breakdown structure of an aircraft system. A Work breakdown structure element may be a product, data, a service, or any combination. WBS also provides the necessary framework for detailed cost estimating and control along with providing guidance for schedule development and control. Additionally the WBS is a dynamic tool and can be revised and updated as needed by the project manager.
|Contents | |[hide] | |1 Overview | |2 History | |3 WBS design principles | |3.1 The 100% Rule | |3.2 Planned outcomes, not planned actions | |3.3 Mutually exclusive elements | |3.4 Level of detail | |3.5 WBS coding scheme | |3.6 Terminal element | |4 Example | |5 Pitfalls and misconceptions |
Example of Work breakdown structure applied in a NASA reporting structure. The Work Breakdown Structure (WBS) is a tree structure, which shows a subdivision of effort required to achieve an objective; for example a program, project, and contract. The WBS may show hardware, product, service, or process oriented. In a project or contract, the WBS is developed by starting with : • the end objective and
• successively subdividing it into manageable components • in terms of size, duration, and responsibility (e.g., systems, subsystems, components, tasks, subtasks, and work packages) • which include all steps necessary to achieve the objective. The Work Breakdown Structure provides a common framework for the natural development of the overall planning and control of a contract and is the basis for dividing work into definable increments from which the statement of work can be developed and technical, schedule, cost, and labor hour reporting can be established. A work breakdown structure permits summing of subordinate costs for tasks, materials, etc., into their successively higher level “parent” tasks, materials, etc. For each element of the work breakdown structure, a description of the task to be performed is generated.  This technique (sometimes called a System Breakdown Structure ) is used to define and organize the total scope of a project. The WBS is organized around the primary products of the project (or planned outcomes) instead of the work needed to produce the products (planned actions). Since the planned outcomes are the desired ends of the project, they form a relatively stable set of categories in which the costs of the planned actions needed to achieve them can be collected. A well-designed WBS makes it easy to assign each project activity to one and only one terminal element of the WBS. In addition to its function in cost accounting,...