Thanks for this try to visualize the processes!

My concern is this "all ideas at once" before even starting to prototype etc. (Let's put it in words from an engineer's perspective: to realize an invention it is not possible to have all solutions in advance to integrate it in existing technic!)

What way do you go, if you are trying to develop something essentially new?

Or, think of your "Think big, start small" - Don't ya have to start small with the documentation, too?

I can't find the prototyping (cycles) in your picture while prototyping is essential within game production.

I think, one has to start with a conceptual minimal list and than cycle through the green part of your picture, while expanding it step by step, depending on the results of the process, and depending on the steps of the financing of the project).

EDIT:

An interesting thing to integrate in such a scheme is the learning curve of oneself and the collaborateurs, a most ignored factor in the discussions about development.

Given the market, hardware and software are permanently changing, one has to react to these changes, inform about them, control decisions, change decisions, learn new tools, decide wether change the tools etc.

Given this is a community of continuesly new starters with developing, it is a developing while getting into the functionallity of the tools etc.