Process industries ML — what evidence will an assessor expect?

For a plant, the assessor is usually a functional-safety assessor, not a regulator reading a submission. The public IEC catalog pages show what each standard asks for and where AI is addressed.

Process-sector requirements. The IEC catalog title is “Functional safety - Safety instrumented systems for the process industry sector - Part 1: Framework, definitions, system, hardware and application programming requirements”. IEC 61511-1:2016 “gives requirements for the specification, design, installation, operation and maintenance of a safety instrumented system (SIS), so that it can be confidently entrusted to achieve or maintain a safe state of the process.”

Software evidence. IEC 61508-3:2010 “applies to any software forming part of a safety-related system or used to develop a safety-related system” and “requires that the software safety functions and software systematic capability are specified”.

AI guidance. ISO/IEC TR 5469:2024, “Artificial intelligence - Functional safety and AI systems”, describes “use of AI inside a safety related function to realize the functionality;” and “use of non-AI safety related functions to ensure safety for an AI controlled equipment;”.

Editorial judgment: The evidence an assessor can credibly accept today is the one the catalog language supports most directly: an ML advisory or optimization layer that is not part of the SIS, with a conventional SIS that holds the process in a safe state independent of it. We have not found an official IEC sentence that lets a trained model carry a SIL claim; if a vendor says it does, ask for the assessor’s written acceptance.