I always had a hard time dealing with the jump from the business model canvas to the agile engineering practices.
After experimenting lots of styles of agile project initiation, or agile project inceptions (as these are named within Thoughtworks), I documented a recipe that has been working really well: https://leanpub.com/tothepoint
This recipe has been helping shaping the MVP (in the arrow between the idea and the build on your five-part version of the Build Measure Learn diagram).
In fact, many colleagues and I have been using this approach in Brazil for a while. There were several build-measure-learn cycles, especially at mid to large organizations trying to be more lean and agile. As the recipe became stable, i decided to translate it from Portuguese to English.
I hope it help other folks (like me) applying Lean Startup concepts on larger organizations.