Comments on _Critical Chain_, ch 17

 Chapter 17

“Remember the criticisms we all had on the way we measure the progress of a project?"

"Yes. Vividly.”

Yes I remember. They measured project progress by taking the total time of the completed steps divided by the total time of the whole project (including the completed and the not yet completed) resulting in a completion percentage. This ignores the critical path.

“Well, we changed the way we measure progress. Progress for us is now measured only on the critical path; what percent of the critical path we have already completed. That's all we care about."

Oh cool. So you still do a completion percentage, but you only factor the steps along the critical path and no others.

They discuss another consequence of their new paradigm.

... "Mark, I understand all of that, but there must be something more. What actually are you doing differently?"

“Nothing." Then, as an afterthought, he adds, "But you have to realize that the whole attitude has changed. As I already stressed, there are no more false alarms. People don't put pressure on others just because their people do not have enough to do." Ruth steps forward. "There is another big difference. We don't have milestones anymore. It's not like it was before, when you knew you were supposed to complete your step in two weeks, so what's the rush. Now, it's different. Either you don't start a step, because it's too early, or, if a path is clear to be worked on, you work on it as fast as you can. You see, we trimmed the times to the extent that people are not sure anymore that they can finish the step on time. They don't dare procrastinate. I would say that the 'student syndrome' basically disappeared. Don't you think so, Mark?"

“Now it's different. We trimmed the times. Now people know that there is a fair chance that they will not finish the step on time. They fully understand why I'm concerned, why I came early to find out where they stand."

“That's makes sense," Ted concludes. "That will have an impact." Then he confesses, "I must say that only now do I see the human behavior aspect. I understood why we should trim the time estimate from a ninety percent chance of completing on-time to only a fifty percent chance, but only now do I see the full ramifications. In retrospect, it's obvious."

“Eliminating the false alarm and actually shrinking the time it takes to perform a step contributed a lot to the reduction of multi-tasking. People do not jump so frequently from task to task. There is much less nervousness. How much does it contribute to the shrinkage of the lead time? I don't know, but it must be substantial."

“How do you do that?" Ted is surprised. "This idea of resource buffer was the only thing out of what we said that I thought was totally impractical. Do you actually force a resource to do nothing one week before it's supposed to work on the critical path? And people go along with it?"

"No. We don't do it that way. A week before the expected time we just remind people that their work on the critical path is coming. Then three days ahead we give another reminder. And then again, one day before, when we know for sure that everything else is going to be ready. The important thing is that people know that when the time comes they must drop everything and work on the critical path."