Degradation-Based State Reliability Modeling for Components or Systems With Multiple Monitoring Positions

Engineering components or systems may have multiple monitoring positions for the degradation observations of single or multiple performance characteristics. For the reliability analysis with multiple degradation processes, the existing works are generally based on the binary-state degradation model and the Copula method, where the component or system survives only if every single monitoring position survives. This article develops a degradation-based continuous multistate reliability model through the definition of the state function, where the component or system state is determined by the states of all the monitoring positions. Furthermore, two reliability analysis frameworks of components or systems with multiple monitoring positions are given: k-out-of-n reliability framework and importance reliability framework. The proposed method not only casts off the binary-state constraint for the degradation modeling, but also gives a new way to analyze the component or system reliability in the case of multiple degradation processes, which are monitored in multiple monitoring positions. A numerical case and a practical case about the train wheel tread are given to demonstrate the availability and the possible advantages of the proposed model.