John Goodpasture had this on his Blog.
"It is very difficult to make a vigorous, plausible, and job-risking defense of an estimate that is derived by no quantitative method, supported by little data, and certified chiefly by the hunches of the managers" - Fred Brooks.
This is more the case than not. One of the principle sources of project failure on the cost and schedule side is the lack of credible estimates. This is not limited to badly managed IT programs. Joint Strike Fighter suffers from the same problem. It is a universal problem.
