I want to deactivate a system instead of the whole part, because there are systems that stop working even if i add OnlyWhenOperational = false to it.
Not currently possible, sorry. I added it to the trello, though: https://trello.com/c/i3lA65g1/154-operational-status-shouldnt-be-part-wide-different-components-should-be-able-to-have-different-operational-statuses
Nice!! I will keep preparing things for when its implemented