Every safety regulation is written in somebody's blood. As such, there are Procedures. They are essential when working in an asynchronous, non-collaborative manner on complex tightly-coupled systems.
To prevent accidentally powering up a circuit which somebody else may be working on, LOTO evolved: Lock Out Tag Out.
https://www.ccohs.ca/oshanswers/hsprograms/lockout.html
It is giving me... *ideas*.