Free Critical Chain: A Business Novel by Eliyahu M. Goldratt Page B

highlight to the class, "the decision of the planner when to start each path. Brian chose the late start for picking the vendors while Ted has chosen the early start."
     
    "Of course," Ted almost shouts. "What's the point in taking unnecessary risks!"

"The point is," Fred interjects, "to postpone the investments until they are really necessary. Don't you think that's just as important?"

"I'm not sure," is Ted's response, but it's clear that he is less sure about his position.

"It's an optimization problem," Brian is confident. "We have to weigh the savings from postponing an investment against the chance of damage resulting from finishing the project a little late."

One thing I passionately hate is optimization problems. There are so many articles about these cases, all with involved mathematical models, all so tough and time-consuming to read. And from my experience, all have little practical use. But what can I do; it is an optimization problem.

Ruth raises her hand. Here it comes. Now I'll be forced to show them the equation and how to solve it. It's going to be a boring and useless lesson. Of course, I don't remember the mathematics by heart. Sighing, I open my notebook and signal Ruth to ask her question.

To my surprise, she starts by saying, "I don't think that it's just a financial consideration. It's much more a management issue."

"Explain." I try not to appear puzzled.

"In a project there are many more paths than in our simplified example; many more entry steps."

"Of course."

"If we start all the paths at their earliest start, don't you think that the project leader will have too much on her hands? From my experience," she adds, "if I start too many things, I'm bound to lose focus, and losing focus is one thing a project leader cannot afford."

I never thought about it this way. To gain time I ask the class, "What do you think?"

"Makes sense," is Charlie's response. "Makes perfect sense. In retrospect, I think Ruth put her finger on the biggest mistake I usually make."

The expressions on most faces indicate they agree with Charlie. Fred maintains his poker face.

"What do you think, Fred?"

"I think that, except for cases where the investment is relatively large, Ruth's argument is much more important than the consideration of postponing an investment."

It takes me some time to realize that he actually agrees with Ruth. Then he explains. "If the project leader loses focus, the project is bound to be very late. The financial penalty of delaying the income from the completed project almost always dwarfs everything else."

Nobody argues. Not even Ted.

"Very nice, Ruth," I congratulate her. "It looks like you hit the nail on the head."

"I haven't finished yet," she declines the compliment. I wait for her to continue.

"Can you repeat what you said about the need to focus on the critical path?" she asks.

I don't have a clue. What is she driving at? But I also don't have any problem repeating myself. "The critical path determines when the project will be finished. Any delay on the critical path will delay the project."

"If we start at the late start, isn't it true for all the other paths as well?" she slowly asks.

I have to think it over. "If we start a path on its late start," I wonder aloud, "then that path doesn't have any time slack. Which means that any delay on that path will also cause a delay in the project."

"Exactly," Ted bursts in. "So if we start everything on its late start, everything becomes important. And I'll have to concentrate on everything. Kiss focusing good-bye."

"Concentrating on everything is synonymous with not concentrating at all," I agree with him. "So where do we stand? If the project leaders use early starts, they will lose focus. If they use late starts, focusing is not possible at all. We have to find the mechanism, the rules, that will enable a project leader to focus."

"Focusing is important," says one of the students, "but there are many other things that are just as