The first and second generation PPM systems work for small size projects but don’t work for medium or large size projects. For example, they work for a two-person two-week project but won’t work for a fifty-people fifty-week project. Why? In the two-person two-week project example, a distortion is unlikely to happen since both people involved in the project can easily remember what happened last two weeks. Even if they didn’t remember and a distortion started, it wouldn’t be hard for them to reveal. The fifty-people fifty-week project example is a different story. A project of such a size would have simultaneous existence of multiple distortions at any time that are difficult to detect and reveal. The opaque environment in turn nurtures more people to misrepresent the facts with defensive lies and lies of omission, which in turn makes the environment even more opaque. Like a rolling snowball, the project environment is getting lies on top of lies until the project is close to its final finish date. All of a sudden, the project changes from 90% complete to 50% complete (see The Myth of 90% Complete). The third generation PPM systems are more methodologies than tools. They break down a medium or large size project into a number of short-time-periods (sprints) so that a distortion is less likely to happen because people involved in a sprint can remember what happened easier in the past couple of weeks. But different from the activities in an independent small size project, the activities in a sprint have interrelationships with the activities in other sprints. The third generation PPM systems only advantage on a certain type of projects such as those for the development of a competitive product and its requirements are market-driven and changing dynamically. But they have serious drawbacks with other types of projects.
The fourth generation PPM systems offer the following benefits: