Verification and performance evaluation of AADL models

This paper reports on a model-based approach to system-software co-engineering which is tailored to critical on-board systems for the aerospace domain but is relevant to a much wider class of dependable systems. Our main contribution is a formal semantics for a greater part of standardised AADL, the Architecture Analysis and Design Language, and its Error Model Annex. It covers nominal and degraded hardware/software operations, hybrid (and timing) aspects as well as probabilistic faults, their propagation and recovery. The accompanying software toolset employs SAT-based and symbolic model checking techniques and probabilistic variants thereof. The precise nature of these techniques together with the formal semantics provide a trustworthy modelling and analysis framework to support, among others, assessment of functional correctness, evaluation of performance measures and automated derivation of dynamic fault trees, FMEA tables and observability requirements.