Agonising over ASILs: controllability and the in-wheel motor

Abstract

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.

Towards increased reliability by objectification of Hazard Analysis and Risk Assessment (HARA) of automated automotive systems

“…However, the methodology for determining these parameters and their quantification is not mentioned. Instead a set of sample tables have been provided (Ellims and Monkhouse, 2012). SAE J2980 provides some guidance to certain degree of objectivity to automotive HARA.…”

“…The first set of parameters were identified from this set. In addition, existing literature was reviewed for factors influencing severity and controllability (Baker et al, 1974;Ellims and Monkhouse, 2012;Green, 2000;Lortie and Rizzo, 1998;Monkhouse et al, 2015;Summala, 2000;Verma and Goertz, 2010). The parametrization of the HARA components should help meet the R1, R2 and R3 reliability criteria defined by (Aven and Heide, 2009) by objectivising the decision making process involved in HARA ratings.…”