Conducting the audit: evidence gathering, sampling, interviewing and observation
This domain tests how you generate, verify and record evidence through interview, observation and document examination, and how you sample without misleading yourself or the client.
Core rules and concepts
- Evidence must be verifiable and traceable: what you saw, where, when, who was present and which record. 'The workshop looked untidy' is not evidence; 'the walkway between press 4 and the packing bench was blocked by two pallets at 10:20, observed with the shift supervisor' is.
- Triangulate. A process conforms when the document, the observed practice and the workers' account agree. Where they diverge, establish which is normal at scale, not which is easier to sample.
- Interview technique: open questions first ('walk me through what you do when a guard is removed'), closed questions to pin a fact. Talk to workers without the supervisor answering, and ask what happens when the task goes wrong.
- Sampling is risk-based and documented: across shifts, areas, contractors, high-hazard tasks and recent change. Avoid the best-performing area and the one person who knows. A sample of one supports an observation, not a system conclusion.
- Observation: follow a task end to end - permit to work, lockout, chemical decanting, changeover cleaning - inspect condition as well as behaviour, and check what the procedure leaves out.
- Opening meeting confirms scope, criteria, plan, channels, safety and confidentiality. Closing meeting presents findings and conclusions, not solutions.
Worked example
You are testing lockout/tagout. The procedure requires a personal lock. At the conveyor the fitter applies a group lock and the supervisor holds the only key. Two fitters say they have never been issued a personal lock. Three sources agree, so this is a system failure rather than a slip: the finding cites 8.1.2 and the organisation's own procedure, states the evidence and dates, and is graded major.
Traps that cost marks
- Accepting verbal assurance without a record or observation.
- Being escorted only along the prepared route.
- Letting the auditee choose the sample or the interviewees.
- Mistaking a document review for an audit of implementation.
- Writing opinion and remedy into what should be an evidence statement.