Agonising over ASILS: Controllability and the in-wheel motor

In the automotive domain the standard ISO 26262 places significant emphasis on the assignment of Automotive Safety Integrity Levels (ASILs). In particular much of Part 3 of the standard is dedicated to the process that determines the three factors that contribute to the final assigned ASIL value: exposure, severity and controllability. In this paper we examine some of the issues that the authors have encountered during the development of an in-wheel electric motor and will argue that the perceived emphasis on ASIL ratings, in the context of developing a safe system, is misplaced and potentially counterproductive.