ANSI/UL 4600 Version 2 (2022)
Version 2 of ANSI/UL 4600 has just been issued. This standard provides guidance on how to ensure that autonomous vehicles safety cases are created and maintained to ensure acceptable safety for deployment.
Since version 1 of the standard was issued in April 2020, the Standards Technical Panel members (the voting committee) and stakeholders have been involved in suggesting clarifications, upgrades, and other improvements as part of the standard's continuous improvement process.
Version 1 of the standard included chapters on: terminology, safety cases, risk assessment, interaction with humans, autonomy functions, software/system engineering processes, dependability, data/networking, verification/validation/test, tool qualification/COTS/legacy components, lifecycle concerns, maintenance, metrics, and assessment. The standard is designed to work with other safety standards such as ISO 26262 and ISO 21448 to make sure that all the bases are covered for system-level safety on autonomous road vehicles.
Version 2 has some substantive changes:
- The assessment terminology and role of independent assessment have been changed. This is compatible with the previous approach except that the independent assessor has a more substantive role.
- Self-assessment: the development team creates and vets its own safety case.
- Independent assessment: an independent organization examines both the form and the technical substance of the safety case to ensure it is acceptable. (This independent organization might be within the same company at an arms-length relationship, or could be an external assessor at the company's option.)
- Significant clean-up of the discussion of safety case terminology and structure. This is overall a significant improvement of the ideas that were already there in version 1, but a lot of work went into this area.
- The terminology section has been substantially rewritten to clean up wording and improve alignment with other standards without substantively changing the intended meaning of terms being used.
You can find a pointer to a copy of the newly released version 2 including FREE (with free digital account) digital access to a full copy of the standard, a list of committee members, and more here: https://users.ece.cmu.edu/~koopman/ul4600/index.html
The official news release from the standards organization is here: https://ul.org/standards-and-engagement/presenting-standard-safety-evaluation-autonomous-vehicles/second-edition