Network Approaches to Finding the Reliability of Repairable Systems

Methods of determining the availability and failure frequency of systems of independent repairable units are discussed. The methods are based on representation of the system by a network or reliability block diagram. Conditions for such representation are given and methods of drawing the network are described. Two approaches for determining system reliability given the network and unit characteristics are reviewed and developed. One approach is based on successive reduction of the network and is particularly useful for series-parallel systems. The other approach is based on the determination of either the minimal paths or cuts and subsequent formula manipulations. Both approaches enable quite large systems to be analyzed.