[hackuser]

> As a counterpoint, zero defect policies could be be harmful. If everyone must take a test and score 100% or otherwise end their career, shenanigans happen.

It's not a counterpoint, it's a consideration when designing the system. Taking this into account, the system must still function 100% of the time. If what you describe did happen, than the cause of failure would shift somewhat from the officers to the designers, but the system still failed (however, one must question the judgment and character of anyone who cheats on a nuclear weapons launch qualification test, no matter how hard it is).

[AdamJacobMuller]

Right. A system can function at (effectively) 100% correctness being composed of individuals who are not 100% perfect (because nobody is).

If 1 person is 99.99% correct, how correct are 3 people when consensus is required to make a decision? 5? Its just math.

[eutectic]

You can only 'do the math' if you assume uncorrelated errors and no unanticipated or emergent failure modes.