Component Integrated Importance: Modeling Complex Aging Systems

One objective of studying complex system reliabilities using block diagrams is to determine which individual components contribute most significantly to the reliability of the assembled system. A well-known method is to compute the Birnbaum component importance (BCI) of every component, then prioritize reliability improvement efforts on the components that have larger importance values. In the literature and in practice, there are two versions of BCI, one is static and the other is dynamic. The static version computes BCI of individual components at a given time t, while the dynamic version computes BCI of individual components at many time points and forms curves for individual components. Both BCI versions (static and dynamic) assume the system is new. However, component importance can change dramatically as systems age. We will present the details of our study. We will discuss two alternatives that consider component importance measures that involve system aging. One published alternative is known as the Component Integrated Importance [2]. The other is conditional BCI.