Sangiovanni-Vincentelli,A.: A Formal Approach to Fault Tree Synthesis for the Analysis of Distributed Fault Tolerant Systems

Designing cost-sensitive real-time control systems for safety-critical applications requires a careful analysis of both per-formance versus cost aspects and fault coverage of fault tol-erant solutions. This further complicates the difficult task of deploying the embedded software that implements the con-trol algorithms on a possibly distributed execution platform (for instance in automotive applications). In this paper, we present a novel technique for constructing a fault tree that models how component faults may lead to system failure. The fault tree enables us to use existing commercial anal-ysis tools to assess a number of dependability metrics of the system. Our approach is centered on a model of com-putation, Fault Tolerant Data Flow (FTDF), that enables the integration of formal verification techniques. This new analysis capability is added to an existing design framework, also based on FTDF, that enables a synthesis-based, correct-by-construction, design methodology for the deployment of real-time feedback control systems in safety critical applica-tions