Audit
As for the Security Audits, The guard force should be performance-audited at least annually. This process may be outsourced to ensure objectivity.
A documented assessment of the performance of the security programme, including equipment, manpower, procedures, and employee compliance. Security audits are usually carried out against a pre-defined standard including vulnerability assessment.
As always, the starting point is Design basis threats and Security Risk analysis. Security Risk Analysis identifies the severity of the threats. For facilities with an unacceptably high consequence of loss, even when the likelihood of adversary action is low.
Audits start with examining if such security measures applied correctly and ends with reporting the effectivity of physical security, procedures, guarding and response.