Well the games I’m interested in making are simple in nature. There aren’t too many features for them. So I think that modular framework is the best idea so that content creation can be as fast as possible. So, in my opinion, for my practices, I would want the design document to be the first thing that is completed and never changed… and I would want the production of assets(and thus their migration into content) to never start unless I was absolutely positive that the framework matched the design and was completely working.