Reliability Modeling of Mutually DCFP System Considering Degradation Causes the Shock Threshold Descent

Many systems experience dependent competing failure processes (DCFP) resulting due to degradation processes and random shocks. In some complex systems, the threshold of random shocks will descend because of the degradation processes. According to previous researches, two cases of shock threshold descent will be considered. The first case is the hard failure threshold decent to a lower value when derogation exceeds the critical degradation value. The second case is the hard failure threshold decent continuously with the increasing degradation. In mutually DCFP system, the two cases of hard failure threshold decent will exist simultaneously, so they compete with each other. In this paper, a case of laser lithography machine will be introduced to verify the theory derivation. The Monte Carlo sampling method will be used to sample and simulate the case data to obtain the reliability of the system. The result showed that when shock threshold descent, the reliability of the system drops significantly.