Advanced Hazard Analysis and Risk Assessment in the ISO 26262 Functional Safety Standard Using Rigorous Simulation.

With the increasing level of automation in road vehicles, the traditional workhorse of safety assessment, namely, physical testing, is no longer adequate as the sole means of ensuring safety. A standard safety assessment benchmark is to evaluate the behavior of a new design in the context of a risk-exposing test scenario. Manual or computerized analysis of the behavior of such systems is challenging because of the presence of non-linear physical dynamics, computational components, and impacts. In this paper, we study the utility of a new technology called rigorous simulation for addressing this problem. Rigorous simulation aims to combine some of the benefits of traditional simulation methods with those of traditional analytical methods such as symbolic algebra. We develop and analyze in detail a case study involving an Intersection Collision Avoidance (ICA) test scenario using the hazard analysis techniques prescribed in the ISO 26262 functional safety standard. We show that it is possible to formally model and rigorously simulate the test scenario to produce informative results about the severity of collisions. The work presented in this paper demonstrates that rigorous simulation can handle models of non-trivial complexity. The work also highlights the practical challenges encountered in using it.