Investigation of optimal redundancy for a specific system objective

Component redundancy is an effective technique for reducing system unavailability. However, the mathematical models relating redundance and unavailability are generally complex, and casual inspection does not reveal which components should be made redundant to reduce unavailability. This paper develops a method for determining which components are made redundant with the greatest concomitant unavailability reduction. The method was used to study three system designs. For each design it was possible to identify several components which could be made redundant with an associated reduction in unavailability. However, the method also demonstrated that making most components redundant does not reduce unavailability, and in one case a component redundancy actually increased unavailability. Application of the present method helps the designer develop insight concerning the role of component redundancy in a system design without complex calculations and interpretations. 6 figures, 1 table