Formal Methods for Aerospace Systems

The size and complexity of control software in aerospace systems is rapidly increasing, and this development complicates its validation within the context of the overall spacecraft system. Classical validation methods are both labour intensive and error prone as they rely on manual analysis, review and inspection. Thus there is a growing trend to incorporate the use of automated formal methods. This chapter introduces the ESA-funded COMPASS project, which aims at an integrated system-software co-engineering approach focusing on a coherent set of specification and analysis techniques for evaluation of system-level correctness, safety, dependability and performability of on-board computer-based aerospace systems. Its modelling features and supporting toolset provide a unifying framework for system validation, employing state-of-the-art temporal-logic model checking techniques for infinite-state transition systems, both qualitative and probabilistic, with extensions to fault detection, identification and recovery (FDIR) and safety analysis. We provide an overview of the technology and of the results that have been achieved so far, and address several challenges for future developments. Current efforts of the project consortium concentrate on improving and advancing both process as well as technology of the COMPASS approach, with the goal of bringing the methods to higher levels of technology readiness.