Safety and reliability of non-repairable systems

The need for safety is vital in many systems, e.g. an industrial process in which a non-detected failure can be catastrophic. But, from a lifetime point of view, this safety factor is generally incompatible with that of reliability. In this paper a comparison is made of the values of these two parameters for several redundancy schemes. These comparisons show that very careful choice has to be made which is governed by the requirements of the system (complexity, mission time, safety,...)