Issue No. 01 - January-March (2009 vol. 6)
Salvatore Distefano , University of Messina, Messina
Antonio Puliafito , University of Messina, Messina
Dependability evaluation is an important step in designing and analyzing (critical) systems. Introducing control and/or computing devices to automate processes increases the system complexity with an impact on the overall dependability. This occurs as a consequence of interferences and similar effects that can not be adequately managed through reliability block diagrams (RBD), fault trees (FT) and reliability graphs (RG), since the statistical independence assumption is not satisfied. Also more enhanced formalisms such as dynamic FT (DFT) might not be adequate to represent all the behavioral aspects of dynamic systems. To overcome these problems we developed a new formalism derived from RBD: the dynamic RBD (DRBD). DRBD exploit the concept of dependence as the building block to represent dynamic behaviors, allowing to compose the dependencies and adequately managing the arising conflicts by means of a priority algorithm. In this paper we explain how to use the DRBD notation by specifying a practical methodology. Starting from the system knowledge, the proposed methodology drives to the overall system reliability evaluation through the entire phases of modeling and analysis. An example taken from literature, consisting of a multiprocessor distributed computing system, is analyzed.
Control Structure Reliability, Testing, and Fault-Tolerance, Reliability, availability, and serviceability, Theory and models, Formal models, System architectures, integration and modeling
S. Distefano and A. Puliafito, "Dependability Evaluation with Dynamic Reliability Block Diagrams and Dynamic Fault Trees," in IEEE Transactions on Dependable and Secure Computing, vol. 6, no. , pp. 4-17, 2007.