The central function sets an internal audit procedure and programme that covers the SMS, the central function and every site, each audited at least every year (more often if risk calls for it) as a full system audit against the scheme, by internal auditors it assigns who are independent of the area audited. Internal audit reports go through technical review at the central function, which also closes the resulting nonconformities, and auditors and reviewers are monitored for competence and performance with follow-up acted on promptly.
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.