There is a whole family, with the parent being IEC61508. Then 61511, 62026, etc etc. TUV and Exida offer training to become a certified practitioner, which is

There is a whole family, with the parent being IEC61508. Then 61511, 62026, etc etc. TUV and Exida offer training to become a certified practitioner, which is a requirement of the standard. Warning, it's not your grandmother's software, there is no "move fast and break things", traditional application is waterfall and v-model, with full traceability. My company was involved with a new mine winder, it was a bit more involved than usual, but from first inquiry until first use was around 8 years.