written by: Jean Scheid
• edited by: Michele McDonough
• updated: 1/2/2011
When considering the importance of defining a project's duration, managers should understand the role of the WBS in the project planning lifecycle. By using the WBS as a strong project foundation with timelines, projects can flow smoothly.
slide 1 of 2
What is the WBS and Why Is It Important?
The WBS, or the Work Breakdown Structure, is essential as part of a project's lifecycle and timeline. An important part of project planning, the WBS begins with a hierarchy of tasks and levels that help to identify how the project will flow within a designed timeline set by the project manager. The Project Management Institute defines the WBS as, "Representing the sum total decomposition of all work that the project encompasses, from beginning to end."
So, didn't you already discuss this in your project initiation meetings? Weren't teams chosen and tasks assigned? Isn't everyone on the same page and ready to go?
Perhaps, but utilizing a WBS to outline where the project will start, what phases, levels, and tasks will be first, second, third, and so on, and the project's duration is essential any project's success. Skipping the WBS could cause delays, confused tasking by team members, and project overruns. The WBS also helps to define the specifics of the project outlined in the project scope.
Generally, a WBS should begin in two stages. The first stage is to hold a team meeting. At this meeting your first hierarchy level begins, the project title. From there your second stage contains descriptive details of all the deliverables that will need to be performed to complete the project and on what timeline. A Guide to the Project Management Body of Knowledge, or PMBOK Guide, offers utilizing the 100% rule in your second stage of hierarchy. In other words, the WBS should define 100% of everything contained in your scope statement and project plan. Most project managers who utilize a WBS will realize a 90-95% goal, a highly acceptable level when using a work breakdown structure.
Once you've have the two hierarchy levels set, begin with the decomposition, or the breakdown of the deliverables of the project and set timelines. These deliverables, attached in tree form to the hierarchy, are considered work packages. Work packages should be constantly reviewed and monitored by the project manager and given a timeline upfront. The PMBOK Guide suggests a work package be no less than eight hours but no more than eighty hours.
The importance of defining a project's duration becomes something you and your team members can see, feel, and touch if you utilize a WBS in the project's lifecycle. Avoiding the all important work breakdown structure can be costly.