The thing about R & D is that most of the time what's needed is overcoming difficult but important milestones if not accomplishing actual major breakthroughs.

The thing about R & D is that most of the time what's needed is overcoming difficult but important milestones if not accomplishing actual major breakthroughs. Failure on the preliminary R & D can be a complete show-stopper before you even get started. OTOH with such limited, poor & incorrect documentation pertaining to the hardware & software, especially in combination with each other, a strong background in the Experimentation & Discovery aspect of R & D is often the only way to achieve your objective when the intended initial logical approach fails to perform as it is supposed to do. This need can penetrate beyond maintenance all the way to end-of-life. One reason maintenance can chew up so many man-hours.