Sometimes it's best to get answers from the horses mouth - meaning the resident expert. This is ideally the person who created a thing, but can also be the pers

Sometimes it's best to get answers from the horses mouth - meaning the resident expert. This is ideally the person who created a thing, but can also be the person currently responsible. If no such person even exists for critical infrastructure, your company is IMO in trouble. Yes, documentation is important and should be kept up to date. People should consult documentation, and update it if it turn out to be old. But real, up to date, or deep understanding does not exist outside of human brains.