An easy-to-use, efficient tool-chain to analyze the availability of telecommunication equipment

The tool OpenSESAME offers an easy-to-use modeling framework which enables realistic availability and reliability analysis of fault-tolerant systems. Our symbolic engine, which is based on an extension of binary decision diagrams (BDDs), is capable of analyzing Markov reward models consisting of more than 10(8) system states. In this paper, we introduce a tool chain where OpenSESAME is employed for specifying models of fault-tolerant systems, and at the back end our symbolic engine is employed for carrying out numerical Markov reward analysis. For illustrating the applicability of this approach, we analyze a model of a fault-tolerant telecommunication service system with N redundant modules, where the system is available as long as at least K modules are available. Based on this model, it is shown, that the suggested tool chain has more modeling power than traditional combinatorial methods, e.g. simple reliability block diagrams or fault trees, is still easy-to-use if compared to other high-level model description techniques, and allows the analysis of complex system models where other tools fail.