Audit execution and evidence collection
This domain tests whether you can gather sufficient and appropriate evidence, follow it to a defensible finding, and communicate clearly during fieldwork. Audit execution includes the opening meeting, interviews, document and record review, site observation, sampling, evidence evaluation, finding classification, and daily debriefs.
Core rules and concepts
- Evidence must be sufficient and appropriate: sufficient means enough to support the conclusion; appropriate means relevant and reliable.
- Triangulate: corroborate interview statements with records, observation, and physical conditions. A single source is rarely enough for a major finding.
- Sample deliberately: select based on risk, volume, prior results, and process criticality; record what was sampled.
- Classify findings consistently: conformity, nonconformity, observation, or opportunity for improvement, according to the audit criteria and client definitions.
- Maintain an audit trail: record source, date, sample, criterion, and the evidence that supports each finding.
Worked example
An auditor is told that effluent pH meters are calibrated quarterly. The calibration schedule says quarterly, but the log shows the last calibration was seven months ago. The auditor checks the permit condition, the monitoring procedure, and two months of pH records. The finding is a nonconformity against the calibration control because the record contradicts the procedure and the permit monitoring relies on that meter. The auditor does not conclude that the discharge was noncompliant without effluent data; the finding is limited to the control failure. This shows the difference between a control nonconformity and a compliance exceedance.
Traps that cost marks
Accepting verbal assurance without records; treating one sample as the whole population; overstating a finding beyond the evidence; and failing to record the criterion. Another trap is arguing with the auditee instead of documenting the evidence and escalating through the agreed process.