Automated Verification of Dynamic Reliability Block Diagrams Using Colored Petri Nets

The increasing reliance on computer technology nowadays has resulted in a rapidly growing need to build reliable and fault resistant computer-based systems. Computer system reliabilities are conventionally modeled and analyzed using techniques such as fault tree analysis (FTA) and reliability block diagrams (RBD), which provide static representations of system reliabilities. A recent extension to RBD, called dynamic reliability block diagrams (DRBD), provides a framework for modeling dynamic reliability behaviors of computer-based systems. However, analyzing a DRBD model in order to locate and identify design errors, such as a deadlock error or a faulty state, is not trivial when done manually. A feasible approach to verifying a DRBD model is to develop a formal model of the DRBD, and analyze it using programmatic methods. In this paper, we first define a reliability markup language (RML) that can be used to formally describe DRBD models. Then we present an algorithm that automatically converts a DRBD model into a colored Petri net (CPN). We use a case study to illustrate the effectiveness of our approach and demonstrate how system properties of a DRBD model can be verified using an existing Petri net tool. Our approach is compositional and provides a potential solution to automated verification of DRBD models.