The Waterfall methodology was a historic accident and they knew it
I don&#x27;t know about an accident, necessarily.  It&#x27;s got two important things going for it.<p>1.  It lets everyone involved cover their ass.  &quot;All I&#x27;m responsible for is my function.  There was a problem with my inputs, so no wonder my outputs suck.  Don&#x27;t blame me, my inputs are all right there in black and white, and you signed off on them.&quot;<p>2.  It gives people the comforting feeling that they can predict the future, and then do things like plan budgets or negotiate fixed price sales contracts.  Predicting the future is irresistible for people who handle money. As fictional as it might be.<p>So those two things, I think they have a momentum of their own, and without constant vigilance and effort, for most domains, waterfall development is a sad, inevitable default.