A Reliability Evaluation and Optimization Policy for Two-phase Industrial Plants Considering Time-varying Stochastic Environmental Effect

Environmental effects are key factors that affect the degradation accumulation over the lifetime of diverse industrial plants, especially for plants exposed to harsh environment. To evaluate the reliability of system and perform preventive in time, an assessment and decision-making policy considering plants exhibiting two-phase environmental degradation characteristics is proposed. The cumulative impact of environmental effects on degradation behavior is quantified through the establishment of a time-varying stochastic environment model. A two-stage nonlinear stochastic process with environmental covariates is to capture the long-term degradation evolution. Through detection, the accumulation of real-time degradation is found, and the occurrence of hidden defects can be sensed, and then replacement decisions are made according to a pre-determined threshold. Through the joint optimization of inspection intervals and threshold limits, the long-term operational cost is optimized. A numerical experiment is conducted to validate the advantages of the policy, particularly in terms of downtime and cost reduction.