A supplier audit checks whether a supplier can consistently deliver what you need, safely, legally and to the quality you expect. Done well, it reduces supply risk and gives you evidence when customers or regulators ask how you control your supply chain.
1. Decide which suppliers to audit
You rarely need to audit every supplier in the same depth. Rank suppliers by risk:
- Critical: suppliers whose failure would stop production or affect product safety. Audit these before onboarding and at least yearly.
- Important: suppliers that are hard to replace or handle sensitive data. Audit before onboarding and every one to two years.
- Low risk: easily replaced suppliers of non-critical goods. A short self-assessment is usually enough.
2. Use one checklist for every supplier
Consistency is what makes audit results comparable. Group questions into categories, such as company and compliance, quality management, capacity and continuity, and ethics and sustainability, and ask the same questions of every supplier in the same tier.
Write questions that can be answered Yes or No, and ask for a reason and supporting evidence. "Is incoming material inspected and the results recorded?" is better than "Describe your inspection process", because it produces a clear answer you can verify.
3. Choose self-assessment, remote or on-site
- Self-assessment: the supplier answers your checklist and uploads evidence. Fast and scalable, and the right starting point for most suppliers.
- Remote audit: you review the self-assessment with the supplier on a call and ask for extra evidence where answers are weak.
- On-site audit: you visit the site. Reserve this for critical suppliers or where the self-assessment raised serious concerns.
4. Ask for evidence, not just answers
An answer without evidence is a claim. For key questions, ask for certificates, procedures, inspection records, photos or logs, and check that dates are current and names match the supplier.
5. Score the results and agree actions
Score each category so you can see where the risk sits. For every No, or every Yes with weak evidence, agree a corrective action with an owner and due date. Decide whether the supplier is approved, approved with conditions, or not approved.
6. Follow up and re-audit
Track corrective actions until they are closed, and set the next audit date based on the supplier's risk tier and score. Comparing scores year on year shows whether suppliers are improving.
Checklist to get started
Our free supplier audit checklist covers 16 questions across four categories. Use it as it is, or adapt it to your industry.