Conducting the audit: opening meeting, evidence gathering, sampling and interviewing
This domain tests the mechanics of the audit on site: how the audit is opened, how evidence is obtained, how samples are chosen, and how interviews are used to test the system rather than the person.
Opening meeting
Purpose: confirm the plan, scope, criteria, timetable and communication channels; explain methods and sampling; confirm confidentiality; explain how findings will be reported and when the closing meeting will be held; confirm escorts, safety and emergency arrangements; answer questions. Keep it short and management-level, and use it to resolve access problems before they consume audit time.
Evidence
Evidence comes from interviews, observation of activities and conditions, documents and records, and data. Evidence must be verifiable and recorded. Use an audit trail: start from a record and trace back to the activity, or start from the activity and trace forward to the record. Corroborate: a single interview statement is weak evidence; confirm with observation or documentation.
Sampling
You cannot examine everything, so sample enough to be representative and defensible. Bias the sample toward risk: significant aspects, new processes, recent changes, previous problem areas, shift work and contractors. State the sample: "three of twelve waste transfer notes for March". Random sampling alone can miss systemic failure; judgemental risk-based sampling is normal in EMS audits.
Interviewing
Use open questions first ("walk me through what happens when a drum is damaged"), then closed questions to confirm. Avoid leading questions. Ask "show me" rather than "do you…", because observed behaviour outranks described behaviour. Interview where the work happens, not only in managers' offices, and check shifts and contractor workers.
Worked example
On a site tour the auditor sees two 205-litre drums of waste solvent standing on bare ground beside a yard drain, although the procedure requires secondary containment and covered storage. The auditor asks the warehouse supervisor, checks the inspection log and finds no entries for six weeks. Evidence is observation plus interview plus record. The finding is raised against clause 8.1 and the organization's own procedure. Sampling only the drums correctly stored inside the bund would have missed the condition.
Traps
- Accepting "yes, we always do that" as evidence.
- Sampling the most accessible records instead of the riskiest.
- Asking leading questions such as "you dispose of this correctly, don't you?".
- Failing to record sample size and selection method.
- Arguing with the auditee instead of asking for the record.