Degraded systems with multiple performance parameters subject to shocks

The performances of some systems contain multiple parameters, and each parameter has a degradation process caused by gradual degradation and random shocks. This paper proposed a procedure to estimate the reliability of these systems. Firstly, the degradation processes are obtained through performance degradation analysis according to the degradation data when random shocks are not considered. Then the degradation processes are modified based on damages caused by random shocks. Eventually, the system reliability is obtained according to the failure threshold value of the system performance. The four figures obtained in the illustrated example show random shocks make the system less reliable, and the system reliability is higher when the degradation processes are dependent.