Modules in Coherent Multistate Systems

Modules in s-coherent multistate systems are presented as an extension of the binary concept of Birnbaum and Esary. A consequence of this extension is that any subset of the system components can be considered a module. Thus a measure of desirability or usefulness is important. One such measure is suggested along with modular decompositions. General definitions of k-out-of-n: G systems and dual systems are given. Several theorems relating these to modules are presented.