With good estimating techniques, a subject matter expert (SME) can estimate effort reasonably well. Lines of code per hour, objects per day, story points per sprint, all of these we can measure and plot./1/ Estimating a project’s duration , however, vexes every good project manager, and a delayed delivery date is what makes headlines. As opposed to effort, duration is plagued by interruptions, dependencies and merely waiting for, as Dr. Suess says, “a mind-maker-upper to make up his mind.”/2/ In September, I proposed a KPI for getting a handle on project duration called “project duration efficiency” (PDE). In this article, I would like to run through an example to show how easy and helpful it can be.