There is a famous story about how an F16 got grounded because an half inch metal pin was missing from the cockpit canopy. Nobody knew what the pin did or if it was even necessary but you can't fly a plan that 'missing a part'. After several days of being grounded they finally reached out to a guy who had retired 20 years ago who told them the pin was a part of a analogue sensor that had been replaced nearly 30 years ago. Only the pin remained as a vestigial organ since it was part of the airframe design.
It doesn't matter how well you document things there will always be tribal / personal knowledge.
Even if stuff is written down you have to know where to look.
It doesn't matter how well you document things there will always be tribal / personal knowledge.
Even if stuff is written down you have to know where to look.