Simulations are only evaluated automatically when this is has been specified in the module. The score will then be determined by three factors:
Efficiency (50%): Unnecessary actions, like replacing a part that was not faulty, will result in a lower percentage.
Tidy work (50%): When things are not returned in a correct state, the percentage is will be lower.
The number of attempts before the failure is solved: For every failed attempt, the score is halved.