I assume training follows with field repairs necessary to keep equipment running. With the miniaturization of tech, no one is going to be replacing chips or wires on boards, just swap the whole board with a spare.
Depends, because if you got the single components you can use them to repair multiple boards, while if you go the spare way you need to keep some spares for each specific board. So I think it's debatable whether the spare way is actually a better way or not. Maybe the best way would be a mix of the two: use a spare to be able to quickly repair the equipment but then later take the time to find out the single component that broke and replace it so the old board becomes a spare one. This way you can avoid having stacks of spares and you still have quick repairs.
