A professional who audits an organization\'s Lean and/or Six Sigma approach as per the international standard ISO 18404:2015 is called an ISO 18404 Certification Quality Auditor. This standard defines the capabilities required by individuals and organizations applying Lean and Six Sigma for fostering operational effectiveness, constant improvement, and measurable quality outcomes. An ISO 18404 Certified Quality Auditors primary responsibility is to ascertain whether individuals and organizations meet the specifications for Six Sigma Green Belts, Six Sigma Black Belts, Lean Practitioners, and Lean Leaders. Individuals qualified in ISO 18404 certification, unlike conventional quality auditors, are specifically trained to verify conformity to competency-based standards of performance, not procedure and documentation conformance. Because of this, they play a critical role in verifying the formation of competencies and cultural alignment to Lean Six Sigma concepts.