How can systems be optimally maintained while considering warranty periods? This research addresses the development of an opportunity-based age replacement policy for a system operating under warranty. The study examines a system with a warranty period (0, S] where minimal repairs are performed upon failure within the warranty. Beyond the warranty (S<x<T), a preventative replacement occurs with probability p upon opportunity; otherwise, a corrective replacement follows failure. A final preventative replacement is executed at age T. With T as the design variable, and assuming a Poisson process for opportunity occurrences, the research formulates a long-run average cost model under a general failure time distribution. One sufficient condition for a unique, finite optimal T* is shown to be that the failure time distribution is IFR (Increasing Failure Rate). Numerical examples are also presented for the Weibull failure time distribution, offering practical insights for system maintenance optimization.
This paper, published in the International Journal of Reliability, Quality and Safety Engineering, directly reflects the journal's focus on advancing methodologies for ensuring system reliability and safety. The proposed opportunity-based replacement policy provides a valuable contribution to the field, aligning with the journal's audience interested in engineering and risk management.