WBS!? What’s a WBS? A new wrestling network? A new basketball league?
No, it stands for Work Breakdown Structure.
You may recall that I have stressed the importance of knowing the deliverable and its importance in grant applications and in managing projects. Well, the WBS technique is deliverables-on-steroids.
In its simplest form, a WBS is a hierarchy of deliverables that completely define the project.
a. A product-oriented family tree composed of hardware, software, services, data, and facilities. The family tree results from systems engineering efforts during the acquisition of a defense materiel item.
b. A WBS displays and defines the product, or products, to be developed and/or produced. It relates the elements of work to be accomplished to each other and to the end product. In other words, the WBS is an organized method to breakdown a product into sub-products at lower levels of detail.
The WBS concept was created by the Navy during the development of the Polaris missile as part of the PERT effort. [PERT is Program Evaluation Review Technique. Don’t ask if you don’t already know what that is.] The Polaris project was the first application of modern project management.
Why should you care?
A Work Breakdown Structure defines the output of the project. Knowing the output, you can assign and schedule the work for each deliverable. Then you can estimate the cost. It is the heart of an Earned Value Management System. And each deliverable can have its own specification.
Each item in the office cleaning example above has a standard (no dust), work assignment (Mary does sinks, Joe does exterior walls), schedule (Mary starts on Tuesday at 8 p.m. and ends at 9 p.m; Joe starts on Tuesday a 8 a.m. and ends at 5 p.m.), and cost (sink cost = 1 hour @ $x per hour; exterior wall cost = 8 hours @ $y per hour).
What should you watch out for?
The WBS is focused on deliverables, not tasks.
Let me repeat that: Deliverables, Not Tasks!
If you go to Youtube and search for “Work Breakdown Structure,” you will find a lot of videos that start out by saying that the WBS is a breakdown of tasks.
BEEEP! NO! Next! They don’t understand.
Yes, you ultimately get to specific tasks, but that is only one result of WBS. The misconception that the WBS is a hierarchy of work has been spread as project management software, such as MSProject, has the ability to assign a WBS number to individual tasks, along with the confusion caused by the word “work” in the name. It is easy to assume that building a task schedule is the same as building a WBS, when, in fact, the tasks and schedule are built from the WBS.
Wikipedia article has a good explanation of the WBS concept.
They also state that:
A WBS is neither a project plan, a schedule, nor a chronological listing. It specifies what will be done, not how or when.
A WBS is not an organizational hierarchy, although it may be used when assigning responsibilities.
For a real project management junkie, the definitive document is MIL-STD-881C.