Third party:
"The VAP [Validated Assessment Program] audits carried out on RBA member facilities and their suppliers’ facilities are completed by independent, third-party auditors specially trained in social and environmental auditing and the VAP audit protocol." (p. 1-2)
"Supplier Audits: We audit suppliers that we identify as having “higher risk” in our supply chain. The risk evaluation includes feedback from our supplier assessments and company contacts. These audits are announced and conducted by a third-party firm certified to conduct RBA audits." (p. 2)

Self:
"Our internal auditors, some of whom are certified by the RBA, perform internal audits against the Code at onsemi manufacturing sites every two years. The audit criteria cover five main areas based on RBA audit protocol, including labor, ethics, health and safety, environment and management systems, and include corrective actions." (p. 4)