On periodic maintenance for a protection system

Abstract

This article presents a model for maintenance planning of protection systems, such as isolation valves, circuit breakers, and other safety barriers. These systems are designed to operate on demand and prevent environmental catastrophes. The proposed model is novel because: (i) inspections (functional tests) are fixed and periodic; and (ii) the replacement policy has three-phases, corrective, opportunistic-preventive, and scheduled-preventive. Thus, the system is replaced: at a positive test; at a test regardless of the outcome either if an opportunity arises or when the system reaches a critical age. The model is relevant because periodic inspections are largely the practical, engineering reality, and particularly useful for geographically distributed systems, for which there is limited time and resources for maintenance. The paper provides a web-based application as a demonstrator of the proposed model. The study extends and refines well-known policies from the literature, providing valuable insights about applicability across various parameter settings.