The Ultimate ISO 17025 Internal Audit Checklist Guide
The Internal Audit is your only chance to find mistakes before the external assessor does. Yet, most laboratories fail this step because they treat it as a paperwork exercise rather than a forensic investigation.
The Trap of "Generic" Checklists
Many Quality Managers download a generic ISO 9001 checklist and try to apply it to a laboratory. This is a critical error. ISO/IEC 17025:2017 has specific technical requirements (Clause 7) that general business checklists completely miss, such as:
- Metrological Traceability (Clause 6.5).
- Evaluation of Measurement Uncertainty (Clause 7.6).
- Ensuring the Validity of Results (Clause 7.7).
Horizontal vs. Vertical Audits
To be fully compliant, your audit program must cover two distinct dimensions:
1. The Horizontal Audit (System)
This checks the "paperwork" across the whole lab. For example, checking that 100% of staff have signed confidentiality agreements, or that the document control procedure is being followed in every department.
2. The Vertical Audit (Job Witnessing)
This is where you pick one specific job (e.g., Job #12345) and follow it from the initial customer quote all the way to the final certificate.
Pro Tip: You must physically witness a technician performing the test. If you only check the paperwork, you will miss technical bad habits.
The "Show Me" Technique
Never accept a "Yes" or "No" answer. If you ask, "Is equipment calibrated?", and the staff member says "Yes," your job is not done. You must say: "Show me the sticker and the certificate." Your audit checklist should have a dedicated column to record this objective evidence.
Need a checklist that covers both System and Vertical audits? See our template.
