The ISO 26262 series (ISO 26262-1-12 (2018)) defines vehicle safety as the absence of unreasonable risks that arise from malfunctions of the E/E systems; it specifies HARA to determine vehicle level hazards as well (see the Functional Safety topic). With the increase in the implementation of ADF in vehicles, more and more systems rely on sensing the external or internal environment and there can be potential hazardous behaviour caused by the intended functionality or performance limitation of a system when identifying hazardous events, even when free from faults in the scope of the ISO 26262 series. The absence of unreasonable risk from these potentially hazardous behaviours related to such limitations is considered as the SOTIF (ISO 21448, 2022).
The cause of SOTIF-relevant hazardous events could derive from some aspect of the system, as well as from external factors. Such causes of hazardous events mainly include (ISO 21448 (2022)): performance limitations, reasonably foreseeable misuse and impact from car surroundings. This topic discusses the main points for achieving the SOTIF when developing an ADF. This topic does not necessarily apply the same terms as used in the ISO standard, but rather tries to point out the sense of important aspects in this context in the language used throughout the document.
The development of SOTIF should comply with the latest international standards, such as ISO 21448 (2022). The ISO 21448 (2022) provides guidance on an iterative function development process to achieve the target of the avoidance of unreasonable risk in both known or unknown and unsafe scenarios. The SOTIF-relevant issues, regarding the systematic development of ADF to support safety by design, have also been addressed and discussed in other international standards, such as ISO/TR 4804 (2020) (this standard has recently been superceded by ISO/TS 5083:2025).
Additionally, the latest guidelines or regulations on the development of SOTIF should also be taken into account, such as the latest guidelines from the NHTSA and SAE for the US, and European Commission within the EU.
Main Question
Is the development of SOTIF compliant with ISO 21448 (2022) and other relevant international standards and regulations?
References
- ISO (2018) 26262-1-12: Road vehicles — Functional safety part 1-12, Part 1 availabe at: https://www.iso.org/standard/68383.html (Accessed: 18 October 2023)
- ISO (2022) 21448: Road vehicles — Safety of the intended functionality. Available at:https://www.iso.org/standard/77490.html (Accessed: 18 October 2023)
- ISO (2020) TR 4804: Road vehicles — Safety and cybersecurity for automated driving systems — Design, verification and validation. Available at: https://www.iso.org/standard/80363.html (Accessed: 18 October 2023)