ISO17020:2012

defined in ISO/IEC 17020:2012, and it applies to any stage of inspection.
ISO 17020, entitled "General Criteria for the Operation of Various Types of Bodies Performing Inspection", is an internationally recognized standard for the competence of inspection bodies. ISO 17020 should not be confused with ISO 9001, which is specific to quality management systems.  ISO 9001 does not require evaluation of the technical competence of an inspection body and it should not be regarded as an ‘acceptable’ alternative to ISO 17020.