Software Fault Protection for Avionics

In this position paper we present an approach for achieving high assurance of flight systems that is related to and complementary with software verification and validation methods. We propose a model-based approach to runtime monitoring and error recovery of flight software, in short, software fault protection. More specifically certain aspects of the intended system behavior are formalized in a model. At runtime the software is monitored and compared with the model. Should there be disagreement, the model specifies a recovery action to perform. Like all V&V processes it is concerned with checking the consistency of the behavior of the software with some other entity such as a formal or informal model, requirements, or a set of test cases. In this case the consistency check is performed in operation rather than during development.