Imagine that we have a system, which has a natural possibility of failure(incredibly small number). Let's put it this way, we input random numbers into this system, and it outputs always 0. It should always output 0. It's not hardcoded. 0 is always a result of complex calculations. But system has possibility of failure, sometimes it outputs 1. For some ridiculously small percentage of values it outputs 1.
The question is: if once in a while we manually input value which should give 1 on the output, would this somehow change the natural possibility of system failure? Would it decrease it? Or would it at least give us some safeness that the failure wouldn't occur in the nearest future?
Background of the problem: Friend of mine has finished her book, and we are trying to cut all possible technical incorrectness from it.