Audit Planning and Preparation
The three anchors
Objectives answer why the audit is being done (verify conformity, qualify a supplier, maintain certification). Scope answers what, where, when, and to what extent - sites, units, processes, product lines, and exclusions. Criteria answer against what - the standard, regulation, SOP, contract, or specification. Confusing scope with criteria is the most common preparation error on exams.
Preparation sequence
Confirm feasibility and resources; review documentation (quality manual, procedures, prior reports, complaints, CAPA status, regulatory correspondence); identify risk-based focus areas; draft the audit plan with timing, roles, and auditee interfaces; build working documents - checklists, sampling plans, forms, note templates; agree logistics and confidentiality.
Sampling
Judgemental sampling is normal in audits; statistical sampling (for example an AQL plan) is used when conclusions must be quantified. Good sampling is risk-based: pick by process criticality, complaint history, recent changes, new personnel, and prior findings, not by whichever binder is on top. Sample trails in both directions - from the record back to actual practice, and from practice back to the record - so you prove the system, not a single transaction.
Traps
- A checklist is an aide-mémoire, not a script; auditors who read it aloud miss the system.
- Document review informs the audit but is never a substitute for objective evidence.
- “We will audit all records” is not a sampling plan.
- A plan written without auditee input invites scheduling chaos and defensiveness.
Rule of thumb
Say it aloud: objectives = why, scope = where and how far, criteria = against what. If you can state all three in one sentence, planning is on track.