OPTIMAL-DESIGN OF REDUNDANT-SYSTEMS FOR IMPROVING FAIL-SAFE CHARACTERISTICS

For systems in which the probability that an incorrect output is observed differs with input values, we adopt the redundant use of n copies of identical systems which we call the n-redundant system. First, it is proved that the n-redundant system that minimizes the mean loss is a k-out-of-n redundant system under the condition that the voter functions perfectly, and a necessary condition for reducing the mean loss by the redundant use is clarified. Next, the paper discusses the redundancy technique for minimizing the probability of dangerous errors. The results provide an effective guide to fail-safe design of systems.