ISO 26262

ISO 26262 is the automotive adaptation of IEC 61508, published in 2011 and revised in 2018, defining functional safety requirements for electrical and electronic systems in road vehicles. It introduces the Automotive Safety Integrity Level (ASIL), a variant of the SIL scale that ranges from ASIL A (lowest) to ASIL D (highest), with an additional grade QM (Quality Management) for non-safety-related functions. The standard covers the entire vehicle lifecycle, from concept phase through production and operation, and mandates hazard analysis, risk assessment, and verification for all functions classified above QM.

The standard's development was driven by the increasing electronic complexity of modern vehicles — particularly the shift from mechanical to electronic control of braking, steering, and acceleration. The Toyota unintended acceleration incidents of the late 2000s, which involved software and electronic throttle control, provided both political momentum and empirical evidence that automotive software required the same rigor as aviation software. ISO 26262's requirements for software unit design, implementation, and verification borrow directly from DO-178B, including the emphasis on structural coverage and traceability.

ISO 26262 reveals the automotive industry's ambivalence about software safety. The standard is comprehensive on paper but inconsistently enforced in practice. OEMs routinely delegate ASIL-rated components to tier-1 suppliers without adequate verification of the supplier's process capability. The result is a compliance theater in which documentation exists but assurance does not. Until an autonomous vehicle catastrophe forces a reckoning, ISO 26262 will remain a standard that the industry follows formally and ignores substantively.