Modeling Security Surveillance Systems With State Dependent Inspection-Maintenance Strategy

Security surveillance systems, which are used to ensure and enhance the safety level, have wide applications in different areas of modern society, from civil to military, such as homes, banks, airports, and nuclear power plants. They are safety-critical systems, which means that the failure of such systems may cause serious consequences such as loss of lives, serious damage of properties, and pollution of environment. This article considers a security surveillance system with two competing failure modes: degradation processes and multiple states. A state dependent inspection-maintenance strategy with imperfect preventive maintenance is designed and applied to this system to improve the performance. The performability and cost models for this system are developed based on these mechanisms. A modified Nelder–Mead downhill simplex method is proposed to determine the optimal inspection-maintenance strategy to minimize the expected long-run cost rate (ELCR) of the system. To the best of our knowledge, this is the first time that both state dependent inspection-maintenance strategy with imperfect maintenance and competing failure modes described by degradation processes are considered in the modeling of security surveillance systems.