Which documentation is essential for an internal auditor to review before the audit?

The essential documentation for an internal auditor to review before the audit is prior audit reports. These reports provide valuable insights into the findings and observations from previous audits, allowing the auditor to understand the context of the current audit. They highlight areas that have required attention in the past, any corrective actions that were implemented, and the effectiveness of those actions over time. This historical perspective helps the auditor assess whether processes have improved, if issues have recurred, and whether the organization is effectively managing its quality management system in compliance with ISO 9001 requirements.

Additionally, prior audit reports often serve as a benchmark for evaluating the current state of the processes being audited, guiding the auditor in developing a focused and relevant audit plan. Understanding past non-conformities and corrective actions can also contribute to a more effective audit process, ensuring that the organization is continuously improving.