I like it. This reminds me of the "tracer bullet" concept, as described in The Pragmatic Programmer by Andrew Hunt and David Thomas. As physical tracer bullets are used to illuminate the path to a target by glowing as they travel, the aptly named software development approach aims at creating a functional, end-to-end version of a system early in the project lifecycle. This strategy balances discovery and outlining, by deliberately planning for development of the minimal functional path that will help discover and overcome criticalities. No big castles of imagination, neither wasteful roaming, but targeted hands-on discovery. Key points here are: end-to-end functionality, real code (not throwaway, unlike a mockup or sketch), feedback-driven, interative improvements, risk reduction. Benefits: clarity, alignment, momentum, adaptability.