A Modular Approach for Model-Based Dependability Evaluation of a Class of Systems

Analytical and simulative modeling for dependability and performance evaluation has been proven to be a useful and versatile approach in all the phases of the system life cycle. Indeed, a widely used approach in performability modeling is to describe the system by state space models (like Markov models). However, for large systems, the state space of the system model may result extremely large, hardening its solution, both when pursuing an analytical and a simulation approach. Taking advantage of the characteristics of a particular class of systems, this paper develops a methodology to construct an efficient, scalable and easily maintainable architectural model for such class, especially tailored to dependability analysis and evaluation. Although limited in its applicability, the proposed methodology shows very attractive because of its ability to master complexity, both in the design phase of the model and, then, in its solution. To better illustrate the proposed methodology, we also offer a case study, selected from the class of systems our work is directed to.