I got pointed at this by a "Electron Geek" website, hackaday.com, which has had thing I've brought here before. But before your eyes glaze over, it is highly appropriate to any enterprise where precision, quality, and metric establishment are needed and the outcome is required to meet certain parameters. Don't get scared off by the author or the title. The lessons are universally applicable. And it ends with an awesome quote. It is the late Richard Feynmans addendum to the Challenger Space Shuttle Disaster. If you are still wondering why you'd want to read such a thing, here's the really short version. If you continue to accept a less rigourous value of your QC beacuse it's always been okay before, then either your metric is wrong-which should not be thown away without responsible and realist reasons for its change, or you are ignoring all the good sound reasons for your metric being correct that established it in the beginning and a catastophic, possibly cascading, failure will be the inevitable result. It's not rocket science For those that are interested enough to continue: https://science.ksc.nasa.gov/shuttle/missions/51-l/docs/rogers-commission/Appendix-F.txt Enjoy! Edit: it's only 6ish pages, in case that makes a difference for someone. Edit again: Here's a video with a former Astronaut explaining this paper, and the concept of normalizing deviancy, clearly to a Fire Fighter conference, with minimal space geek speek. It is in 4 parts however, here's the first. Normalizing deviancy? Oh boy.