Creating a detailed work breakdown structure (WBS) is a critical process in project management. When you have defined each deliverable, you need to determine how, when, and by whom the necessary work will be executed. Up to a point, hierarchical decomposition can be a very useful approach. It allows you to “eat the elephant one bite at a time” so to speak. It also provides the basis for prioritizing, sequencing, and tracking deliverables. In the PMBOK chapter of “Project Scope Management”, you can find sample diagrams showing such a structure at different branch levels:
- The project
- Various phases
- Work packages
Technically, there is nothing to prevent you from further decomposing your project into sub work packages and sub-sub work packages and so forth ad infinitum. However, even with very complex projects there comes a point where this practice has diminishing returns.
The primary question to ask when you are subdividing a project into work packages is “Am I creating more work?” If the administrative time involved in defining, creating, assigning, and tracking a work package is greater than the actual time required to complete the tasks in the work package, the answer is obviously “Yes”. Project management should be about making your job simpler – not more complicated.
As an example of excessive decomposition, let’s say you need 100 widgets assembled for your project. You wouldn’t want your WBS diagram to show each widget as a separate work package that had to be reported on individually. That would require an enormous amount of administrative labor for you and for your team members. At the other end of the scale, you might not want to have a single work project for the whole widget construction deliverable because you have different departments involved. In this situation, it would make more sense to have the sourcing of the widget components listed as Phase 1, the widget assembly as Phase 2, and the widget Quality Assurance inspection as Phase 3.
Too Much Decomposition is Bad for Employees
Basically, you don’t want to turn project management into micro-management. This decreases efficiency and negatively impacts team morale. The individuals actually responsible for completing the deliverables or schedule activities shouldn’t feel that they are being treated as if they don’t know how to do their jobs. This is one reason you may want to have them involved in creating the WBS – especially since they may have additional insight into the most logical way to group various tasks.