In total, only 8.5 percent of projects hit the mark on both cost and time. And a minuscule 0.5 percent nail cost, time, and benefits. Or to put that another way, 91.5 percent of projects go over budget, over schedule, or both. And 99.5 percent of projects go over budget, over schedule, under benefits, or some combination of these. Doing what you said you would do should be routine, or at least common. But it almost never happens.
