The Pragmatic Bookshelf | PragPub February 2013 | Estimation is Evil
It’s based on an unrealistic list of requirements, using weak estimates, made at the moment of maximum ignorance, by people who are always optimistic about their own abilities. It has been squeezed down by managers who think they need to be tough, and sometimes it is just overridden by someone who has made a rash promise to someone higher up the food chain.
Source: pragprog.com