Stochastic Framework for Partially Degradation Systems with Continuous Component Degradation-Rate-Interactions

Many conventional models that characterize the reliability of multicomponent systems are developed on the premise that for a given system, the failures of its components are independent. Although this facilitates mathematical tractability, it may constitute a significant departure from what really takes place. In many real-world applications, system components exhibit various degrees of interdependencies, which present significant challenges in predicting degradation performance and the remaining lifetimes of the individual components as well as the system at large. We focus on modeling the performance of interdependent components of networked systems that exhibit interactive degradation processes. Specifically, we focus on how the performance level of one component affects the degradation rates of other dependent components. This is achieved by using stochastic models to characterize how degradation-based sensor signals associated with the components evolve over time. We consider "Continuous-Type" component interactions that occur continuously over time. This type of degradation interaction exists in many applications, in which interdependencies occur on a continuum. We use a system of stochastic differential equations to capture such "Continuous-Type" interaction. In addition, we utilize a Bayesian approach to update the proposed model using real-time sensor signals observed in the field and provide more accurate estimation of component residual lifetimes. (C) 2014 Wiley Periodicals, Inc.