“A Work Breakdown Structure is a deliverable-oriented hierarchical decomposition of the work to be executed by the project team to accomplish the project objectives and create the required deliverables.”1
A Work Breakdown Structure is a fundamental project management technique for defining and organizing the total scope of a project, using a hierarchical tree structure. The first two levels of the WBS (the root node and Level 2) define a set of planned outcomes that collectively and exclusively represent 100% of the project scope. At each subsequent level, the children of a parent node collectively and exclusively represent 100% of the scope of their parent node.
Complex projects can be overwhelming to the project manager. Instinctively, many project managers will take a multifaceted project and break it down into smaller, more manageable parts. This process is called decomposing the project. The tool most often used to accomplish this is the Project Work Breakdown Structure. The WBS is nothing more than a hierarchical diagram that shows the various elements of the project in pictorial form.
Large, complex projects are organized and comprehended by breaking them into progressively smaller pieces until they are a collection of defined “work packages” that may include a number of tasks. A $1,000,000,000 project is simply a lot of $50,000 projects joined together. The Work Breakdown Structure (WBS) is used to provide the framework for organizing and managing the work.
A well-designed WBS describes planned outcomes instead of planned actions. Outcomes are the desired ends of the project, such as a product, result, or service, and can be predicted accurately. Actions, on the other hand, may be difficult to predict accurately. A well-designed WBS makes it easy to assign any project activity to one and only one terminal element of the WBS.
1 A Guide to the Project Management Body of Knowledge, 3rd Edition (Newton Square, PA: Project Management Institute, 2004) 379.
MICHAEL D. TAYLOR, M.S. in systems management, B.S. in electrical engineering, has more than 30 years of project, outsourcing, and engineering experience. He is principal of Systems Management Services, and has conducted project management training at the University of California, Santa Cruz Extension in their PPM Certificate program for over 13 years, and at companies such as Sun Microsystems, GTE, Siemens, TRW, Loral, Santa Clara Valley Water District, and Inprise. He also taught courses in the UCSC Extension Leadership and Management Program (LAMP), and was a guest speaker at the 2001 Santa Cruz Technology Symposium. His website is www.projectmgt.com.