2oo2: The main disadvantage of a single safety system (that is, non-redundant) is that the only failure immediately leads to a trip. The duplication of channels in a 2oo2 application significantly reduces the probability of a false trip, as both channels have to fail in order the system is placed under shutdown. On the other side, the system has the disadvantage that the probability of failure on demand is twice higher than that of a single channel.