The Product Development Lifecycle that my company has in place is fairly generic (e.g. Commissioning of Project, Requirements Phase, Design Phase, Development Phase, Test Phase and finally Release to Production. It is acually referred to as a "framework" and is meant to be flexible. But for the all too common schedule driven projects, it seems that this generic lifecycle is challenged as inappropriate. I hear statements such as "this is essentially a waterfall lifecycle and is not optimal for complex enterprise projects".

So what product development models out there ARE optimized for complex enterprise types of projects? And are there any models that support placing less emphasis on requirments definition up front and more emphasis on design and develop. If so, do they have proven track records for enterprise (distributed systems) type projects? The product managers want something that will get us to the finish line faster, but yep, they also to spend less time on defining requirements.