The safety integrity level of a function corresponds to a band of tolerable functional failure rate per hour: SIL 4 for a TFFR below 10 to the minus 8 and at or above 10 to the minus 9, SIL 3 for 10 to the minus 7 to 10 to the minus 8, SIL 2 for 10 to the minus 6 to 10 to the minus 7, SIL 1 for 10 to the minus 5 to 10 to the minus 6, basic integrity above 10 to the minus 5 (the 2018 terms define basic integrity by that threshold); a lower rate than 10 to the minus 9 is not claimed for a single function and the systematic-failure requirements of the SIL apply whatever the rate achieved.
This control maps to 1 controls across 1 other frameworks. If you already hold one of them, the evidence you collected for it is the starting point here rather than new work.
Every mapping shown was judged rather than inferred from wording similarity, and the ones that failed review are published too. See the coverage reports and what was rejected.
The graph holds this control, the 1 it maps to, and the evidence behind each claim, over MCP and REST.