I was presenting at the College of Performance Management conference in Florida this week. The topic of credible estimating is always at the top of the list. Here's a phrase that says it all for anyone thinking twice about estimating, not making estimates #NoEstimates, or simply being lazy about how they are estimating
We don't make predictions about the future because we want them to come true. But because we want them to not come true. - Professor Frank Anbari. "Earned Value Project Management Method and Extensions," Project Management Journal, December 2003.
I'll get the attribution from the person who told me this. In the end, to be credible we must manage with our eyes wide open. If you don't have a credible estimate of what it is going to cost, when you are going to be done, and what features you will be able to deliver, in what order, then you'd better find a customer that doesn't really care about those things.