Project Management: A Systems Approach to Planning, Scheduling, and Controlling, Tenth Edition

Trade-off Analysis in a Project Environment

“When we try to pick out anything by itself, we find it hitched to everything else in the universe.”—MUIR'S LAW

16.0 INTRODUCTION

PMBOK^® Guide, 4th Edition

Triple-Constraint Definition

Successful project management is both an art and a science and attempts to control corporate resources within the constraints of time, cost, and performance. Most projects are unique, one-of-kind activities for which there may not have been reasonable standards for forward planning. As a result, the project manager may find it extremely difficult to stay within the time–cost–performance triangle of Figure 16-1.

The time–cost–performance triangle is the “magic combination” that is continuously pursued by the project manager throughout the life cycle of the project. If the project were to flow smoothly, according to plan, there might not be a need for trade-off analysis. Unfortunately, this rarely happens.

FIGURE 16-1. Overview of project management.

Trade-offs are illustrated in Figure 16-2, where the Δs represent deviations from the original estimates. The time and cost deviations are normally overruns, whereas the performance error will be an underrun. ...