Degraded Systems with Multiple Performance Parameters Subject to Shocks

The performance of a degraded system may contain multiple parameters, and each parameter degrades over time. When one of these parameters exceeds a certain threshold value because of degradation, the system will fail. Though extensive research on performance degradation analysis has been done, systems in these papers contain only one performance parameter and random shocks are not considered. The reliability of degraded systems with multiple performance parameters subject to random shocks is analyzed in this paper when the degradation processes of performance parameters are independent and dependent, respectively. In practice, the system performance and damages caused by random shocks must be not less than zero. The system reliability is estimated by Monte Carlo simulation when ranges of the system performance and damages caused by random shocks are taken into account. Eventually, a numerical example is illustrated to demonstrate the proposed method, and four different situations are considered.