Hierarchical models for systems reliability, maintainability, and availability

In this paper, the development of low-cost methodologies for the prediction and evaluation of system reliability, maintainability, and availability (RMA) is considered. Generalized Stochastic Petri Nets (GSPN´s) are used as an analytical modeling tool. A general method of analysis for GSPN´s by state aggregation is presented. This concept of aggregation is then applied to subnetworks, at the GSPN level, to reduce the model complexity. Using the above, a hierarchical model is obtained, based on the notion of time scale decompsotion, for system RMA. The above concepts are illustrated by examples.