I've heard astronauts talk about the normalization of deviance and the risks therein.  What is the normalization of deviance, and how do I avoid it?

The normalization of deviance was a term coined by the sociologist Diane Vaughan who participated in the review of the Challenger disaster.  It was later the the subject of a number of public talks by astronaut Mike Mullane.  The theory is essentially that when we accept deviations from an expected standard, the deviation becomes the standard.  In the Challenger disaster, engineers kept noticing rubber o-rings that came back from tests in an out of tolerance state.  Because there were no dramatic failures during the tests, the engineers adjusted the standard for the o-rings to absorb these abnormalities.  Unfortunately, by normalizing deviance from the expected standard, it led to an o-ring failing during the Challenger launch, and the Challenger shuttle disintegrated in flight.  The normalization of deviance is an important pitfall to avoid when running any organization, but especially those which put its members in high risk situations, such as space travel.  To avoid it, you must remember, or learn, how and why certain standards were developed and adhere to them, even when pressures are high.