| > Can we stop pretending we can forecast the unknown? Except that you're wrong. We predict quite well, thanks. The problem is that everybody ignores the predictions. Most people predict approximately where the 50% probability is with maybe a little fudging. And they tend to be pretty good at it. The problem is that everybody just adds those up. And that's the disaster from a statistical viewpoint. Things can only come in so early, but they can come in infinitely late. A blown schedule on an early dependency throws everything out of whack far more than a late dependency would. We can roll these up in a proper way. We can run Monte Carlo simulations and get "real" numbers. People have done this and the results are remarkably accurate. The problem is that someone in management will always undercut the realistic estimate for personal gain. And then wind up longer than the estimate at the end. And, the worst part is that this is RATIONAL. The only way to get a project completed is to start and get the sunk-cost fallacy rolling in the powers-that-be. |