One of the early lessons in all of our courses asks students to enter a number for the “subjective probability of success” for the project. Several students enter a 1 in this worksheet cell. This indicates that they believe that the project is certain to succeed. In the real world, this is extremely unlikely. Considering all of the possible ways a project might fail, a number in the 90%+ range is so optimistic as to be wishful thinking. I’ve seen so many project fail due to reasons that might have been anticipated and acted on. Looking at a project through rose-colored glasses doesn’t do anyone any favors. The best time to take a cold, hard look at any project is before it has begun. Doing so will save innumerable headaches down the road.