Effective Project Management: Traditional, Adaptive, Extreme, Fourth Edition

Chapter 4. Building the Work Breakdown Structure

Let all things be done decently and in order.

—I Corinthians 14:40

The Work Breakdown Structure

The Work Breakdown Structure (WBS) is a hierarchical description of the work that must be done to complete the project as defined in the Project Overview Statement (POS). Several processes can be used to create this hierarchy, which I discuss in this chapter.

The requirements document is the input to the WBS construction process. If it is complete, then a traditional approach to project management can be taken. In most cases it will not be complete and some other project management approach will have to be taken. I leave that discussion for later and concentrate in this chapter on how to build a complete WBS.

An example of the WBS is shown in Figure 4-1.

To begin the discussion of the WBS, you need to be familiar with the terms introduced in Figure 4-1. The first term is activity. An activity is simply a chunk of work. Later in this chapter, in the section "Six Criteria to Test for Completeness in the WBS," I expand on this definition. The second term is task. Note that in Figure 4-1, activities turn to tasks at some level in the hierarchy. A task is a smaller chunk of work. While these definitions seem a bit informal, the difference between an activity and a task will become clearer shortly.

The terms "activity" and "task" have been used interchangeably among project managers and project management software packages. Some would use the convention ...