What is a Work Breakdown Structure?

Company owners and project managers use the Work Breakdown Structure (WBS) to make complex projects more manageable. The WBS is designed to help break down a project into manageable chunks that can be effectively estimated and supervised.

Some widely used reasons for creating a WBS include:

• Assists with accurate project organization
• Helps with assigning responsibilities
• Shows the control points and project milestones
• Allows for more accurate estimation of cost, risk and time
• Helps explain the project scope to stakeholders

A work breakdown structure is just one of many project management forms and templates.

To start out, the project manager and subject matter experts determine the main deliverables for the project. Once this is completed, they start decomposing the deliverables they have identified, breaking them down to successively smaller chunks of work.

"How small?" you may ask. That varies with project type and management style, but some sort of predetermined “rule” should govern the size and scope of the smallest chunks of work. There could be a two weeks rule, where nothing is broken down any smaller than it would take two weeks to complete. You can also use the 8/80 rule, where no chunk would take less than 8 hours or longer than 80 hours to complete. Determining the chunk size “rules” can take a little practice, but in the end these rules make the WBS easier to use.

Regarding the format for WBS design, some people create tables or lists for their work breakdown structures, but most use graphics to display the project components as a hierarchical tree structure or diagram. In the article Five Phases of Project Management, author Deanna Reynolds describes one of many methods for developing a standard WBS.

A WBS diagram expresses the project scope in simple graphic terms. The diagram starts with a single box or other graphic at the top to represent the entire project. The project is then divided into main, or disparate, components, with related activities (or elements) listed under them. Generally, the upper components are the deliverables and the lower level elements are the activities that create the deliverables.

Information technology projects translate well into WBS diagrams, whether the project is hardware or software based. That is, the project could involve designing and building desktop computers or creating an animated computer game. Both of these examples have tasks that can be completed independently of other project tasks. When tasks in a project don’t need to be completed in a linear fashion, separating the project into individual hierarchical components that can be allotted to different people usually gets the job done quicker.

One common view is a Gantt chart. In a recent article, Joe Taylor, Jr. discusses the Top Ten Benefits of a Gantt Chart.

Building a Desktop Computer - Say your company plans to start building desktop computers. To make the work go faster, you could assign teams to the different aspects of computer building, as shown in the diagram E-1 shown below. This way, one team could work on the chassis configuration while another team secured the components.

click to enlarge

Creating an Animated Computer Game – Now we switch to software project managment, where you startup a computer animation company. To be the first to get your computer game on the market, you could assign teams to the different aspects of writing, drawing and building animated computer games, as shown in diagram E-2 below. Perhaps your key programmer is also a pretty good artist. Rather than have him divide his time and energy by trying to do both tasks, you will realize faster results if the programmer concentrates on programming while his cousin Jenny draws the scenery.

At the risk of sounding melodramatic, the efficacy of a project’s Work Breakdown Structure can determine that project’s success. The WBS provides the foundation for project planning, cost estimation, scheduling and resource allocation, not to mention risk management.