People have questions about the best size for the project work breakdown structure (WBS). The answer depends on the capabilities of the project team and the complexity of the project. That’s because those two issues affect the size of the assignments for the project team members. The WBS for a very inexperienced project team will lean toward relatively small assignments (2-5 days) and results in a larger work breakdown structure. The other extreme is a project team of experienced professionals who are expert in their tasks. To avoid micromanaging these experts, you would make relatively large assignments (7-21 days) and, thus, have a much smaller work breakdown structure. Main WBS Work Breakdown Structure Page
WBS Size Factor #1: Team Member Experience
In most projects, you’ll have a mix of your team members’ experience levels. So you will be designing assignments that range from a day or two for a rookie team member to several weeks for an experienced team member. You’ll also change the size of the assignments based on each team member’s performance. For example, let’s say a person whom you initially assessed as a rookie does very well and consistently produces high-quality deliverables on time. As a result of their performance, you may expand the size of their assignments to give them more freedom and decision-making latitude. You will spend less time evaluating their work because with bigger assignments they are producing deliverables less frequently. Many people working on project teams value the expansion of their decision-making freedom with larger assignments. That is a great performance reward.
If you’re following project management best practices, you’re going to be getting status reports from each of your team members on a weekly basis. The size of their assignment doesn’t matter here. When you give someone a large assignment, they’re still reporting on it every week. So you aren’t “in the dark” about the status of their assignment for weeks at a time.
WBS Size Factor #2: Project Deliverables
The WBS size doesn’t affect the production of project deliverables. You may choose to alter an assignment if the project stakeholders are particularly interested in inspecting one or more of an assignment’s deliverables. However, there are some very important things to avoid in terms of outside influences on the size of your work breakdown structure.
Some project sponsors are wrongly convinced that a big work breakdown structure will give them tight control over the project. This is incorrect on many levels. First, an enormous work breakdown structure takes many hours to update every week. It’s harder to get your team members to give you good status data when they have to report on 10 or 12 micro-tasks. It also takes you longer to enter data and update the schedule with actuals. The typical consequence of a monster-sized work breakdown structure is that the project manager can’t keep up and eventually the schedule is not updated every week. That is the same as not having a schedule.
The other consequence of a very large and very detailed work breakdown structure is it makes your project team members feel they are being micromanaged. They think you and the sponsor don’t trust them to make decisions and are constantly looking over their shoulders. If you’ve ever been micromanaged by someone who knows less about your task than you do, you realize how destructive micromanagement is. You wind up with a project team that takes no responsibility for the results they produce. They simply follow the micro-details in the work breakdown structure. You need to explain this to a project sponsor who wants a very detailed work breakdown structure because the negative consequences are serious.