ABSTRACT
This chapter discusses the methods to model the relationship between system components, which determine overall system reliability. Reliability block diagrams are frequently used to model the effect of item failures on system performance. Item failures often correspond to the physical arrangement of items in the system. A reliability block diagram is a series configuration in which the failure of any one item results in the failure of the system. Accordingly, for the functional success of a series system, all of its blocks must successfully function during the intended mission time of the system. A system is called a standby redundant system when some of its units remain idle until they are called for service by a sensing and switching device. A load-sharing system refers to a parallel system whose units equally share the system function. For example, if a set of two identical parallel pumps delivers x gpm of water to a reservoir, each pump delivers x/2 gpm.
