A model-driven engineering approach to support the verification of compliance to safety standards

Certification of safety-critical systems according to well-recognised standards is the norm in many industries where the failure of such systems can harm people or the environment. Certification bodies examine such systems, based on evidence that the system suppliers provide, to ensure that the relevant safety risks have been sufficiently mitigated. The evidence is aimed at satisfying the requirements of the standards used for certification, and naturally a key prerequisite for effective collection of evidence, is that the supplier be aware of these requirements and the evidence they require. This often proves to be a very challenging task because of the sheer size of the standards and the fact that the textual standards are amenable to subjective interpretation. In this paper, we propose an approach based on UML profiles and model-driven engineering. It addresses not only the above challenge but also enables the automated verification of compliance to standards based on evidence. Specifically, a profile is created, based on a conceptual model of a given standard, which provides a succinct and explicit interpretation of the underlying standard. The profile is augmented with constraints that help system suppliers with establishing a relationship between the concepts in the safety standard of interest and the concepts in the application domain. This in turn enables suppliers to demonstrate how their system development artifacts achieve compliance to the standard. We illustrate our approach by showing how the concepts in the domain of sub-sea control systems can be aligned with the evidence requirements in the IEC61508 standard, which is one of the most commonly used certification standard for control systems.