Audit Execution and Evidence Gathering
Execution is where the auditor gathers objective evidence through interviews, observation, document review, and sampling, then evaluates it against criteria. Understand evidence quality: sufficientity (enough), appropriateness (relevant and reliable), and the hierarchy of reliability (direct observation and records typically stronger than unverified verbal statements). Triangulation - corroborating a claim through at least two independent sources - is central.
Know the mechanics: opening meeting, sampling rationale, traceability of findings to evidence, handling of nonconformities (major vs. minor vs. observation/opportunity for improvement), and the closing meeting where findings are presented for confirmation of factual accuracy. Auditors verify facts, not opinions, and must record evidence so another auditor could reach the same conclusion.
Traps: accepting verbal assurance without verification; over-relying on a single document; recording opinions as findings; confusing a minor nonconformity with an observation; failing to distinguish a system breakdown (major) from an isolated lapse (minor); and letting the auditee negotiate away valid findings. Remember: the auditee confirms factual accuracy, not the auditor's judgment of significance.
Worked example: An operator says waste is segregated, but the container shows mixed hazardous and general waste. The observation plus the physical evidence is a finding; the statement alone would not be. Rule of thumb: If you cannot point to specific evidence supporting a finding, it is not yet a finding.