This International Standard has been drawn up with the objective of promoting confidence in bodies performing inspection. It contains requirements for the competence of bodies performing inspection and for the impartiality and consistency of their inspection activities. It applies to inspection bodies of type A, B or C and it applies to any stage of inspection (for example, design stage, type examination, initial inspection, in-service inspection or surveillance). Inspection bodies carry out assessments on behalf of private clients, their parent organizations, or authorities, with the objective of providing information about the conformity of inspected items with regulations, standards, specifications, inspection schemes or contracts. Inspection parameters include matters of quantity, quality, safety, fitness for purpose, and continued safety compliance of installations or systems in operation. The general criteria with which these bodies are required to comply in order that their services are accepted by clients and by supervisory authorities are harmonized in this International Standard. As a result, this International Standard covers the activities of inspection bodies whose work can include the examination of materials, products, installations, plants, processes, work procedures or services, and the determination of their conformity with requirements and the subsequent reporting of results of these activities to clients and, when required, to authorities. Inspection can concern all stages during the lifetime of these items, including the design stage. Such work normally requires the exercise of professional judgement in performing inspection, in particular when assessing conformity with general requirements. Organisations (for example, accreditation bodies or authorities) which acknowledge the competency of inspection bodies can use this International Standard as the basis for their endorsement. The categorization of inspection bodies as type A, B or C is essentially a measure of their independence. Demonstrable independence of an inspection body can strengthen the confidence of the inspection body's clients with respect to the body's ability to carry out inspection work with impartiality. The document is the German version of the International Standard which has been prepared in a parallel procedure by ISO/IEC and CEN as ISO/IEC DIS 17020:2011 "Conformity assessment - General criteria for the operation of various types of bodies performing inspection (ISO/IEC DIS 17020:2011)". The committee responsible for this standard is NA 147-00-03 AA "Zertifizierungsgrundlagen (Grundlagen zur Konformitätsbewertung)" ("Basic principles for certification (Basic principles for conformity assessment)") at DIN.