Past is History

Description If we keep revisiting past decisions+ we’ll never make it to the end. We don’t have time to catch up each new player in the development process as to why we arrived where we’re at. At some point they’re going to have to take it on faith that our decisions to-date were the best that they could be.
Weaknesses Because innovative research is a voyage of discovery. We should be free to address the foundational basis of our research at any point in the process. Obviously this product has commercial merit or it wouldn't have made it this far along. But perhaps its commercial merit can be enhanced or even protected by revisiting our original assumptions. We don't make a habit of revisiting the past, but we would never discourage any researcher from stress testing our original assumptions at any time.
Appropriate Uses None. Failure to continually test the originating assumptions is a sure path to a major setback in R&D effectiveness at some point in the future. All R&D pursuits should be founded on Alternate Competing Hypotheses+ from the git-go. This means that none of the original hypotheses are ever abandoned. Some are merely out competed by the others, but there's always the chance that a straggler can play catch-up very late in the game.
Further Reading