The Thinker - Rodin   " Every block of stone has a statue inside it and it is the task of the sculptor to discover it." -- Michaelangelo In this regard, building software is not unlike sculpting.  Every solution has a problem and it's the engineer's job to discover it.  Building software is a process of discovery.  It's like groping blindfolded to learn to shape of the subject. Even the best business or product partner will struggle to elucidate and codify all of the idiosyncrasies and edge cases of a problem.  Where humans would generally chose to "cross that bridge when we come to it," the computer throws a temper tantrum and refuses to move on.  Humans are flexible and adaptable.  Computers are not.  Ultimately, it's the engineer who's going to have to uncover and clarify the details with subject matter experts in order to satisfy our implacable adversary, the computer. The Intial Outlay This is precisely why estimating the cost of a software