Optimal Design for System Reliability and Maintainability

A complex system consisting of N modules that are logically interconnected for mission success is to be placed in the field for a fixed period of time. For some modules, standby units can be provided, for others this option is not available, but we must select from among several design alternatives differing in cost, weight, and reliability. The problem is to determine simultaneously the module designs and the numbers of standby units to maximize the system reliability, subject to cost and/or weight constraints. Other authors have considered a similar problem for a pure series inter-connection of modules, but we permit the system to be any configuration of modules in series and/or parallel. A dynamic programming model is presented for this problem. The notion of the generalized decomposition operator is used to develop a set of recursive relations. An example is included.