During an ISO 9001:2015 internal audit, best practices include ensuring that internal auditors are competent and impartial, meaning they should not audit their own work. The audit should cover all areas of the standard, focusing on complex processes where nonconformities are more likely. The process involves planning the audit schedule, conducting the audit, reporting findings, and following up on issues or improvements.

When addressing nonconformities, the organization should control and correct the nonconformity, evaluate the need to eliminate its causes to prevent recurrence, implement corrective actions, review the effectiveness of these actions, and update documentation if necessary.