Systematic evaluation of fault trees using real-time model checker

Abstract

Fault Tree Analysis(FTA) is a means for analyzing causes of hazards. The result of the analysis is a set of combinations of component failures that can result in a specific malfunction. FTA is useful to analyze safety of systems. However, it is a manual process and was not supported by systematic construction process, so fault tree can be inconsistent or insufficient. Unfortunately, there have not been appropriate methods to verify or assure correctness of fault trees. Model-checking is one of the most successful techniques for automatic verification of concurrent finite-state systems and has been usually used to verify whether system design satisfies some properties. In this paper, we propose the way of correcting a fault tree using model checking. To compensate a fault tree, we make formulas for nodes in fault tree and then, verify the formulas with real-time model checker UPPAAL. We analyze the result of verification and reflect the result to the fault tree.