It’s a tale as old as project management itself. Somebody works up a very detailed project schedule and even assigns specific resources to tasks. This person even manages to do some basic allocation so Jake from engineering isn’t working 120-hour weeks for the next five years.

But in all the diligence and detail, a couple of things are overlooked. The person forgets that everybody on the project has “a day job” they still have to get done, and that recurring events like annual quality reviews or year ends or whatever still happen. In failing to account for these, the person puts the project at risk of an overly optimistic timeline with unrealistic true allocation.

Suppose Jake from engineering is assigned to three projects. Each project believes it has about 33 percent of Jake’s time, and each project manager builds a schedule accordingly. That’s all well and good in a two-dimensional view, but life is rarely lived in fewer than three dimensions. In reality, Jake also has operational and special duties he has to get done. After all, Jake is out to please his boss, and if that conflicts with the project managers, then so be it.

 …