Putting into operation and operating machines and plants in the industrial or manufacturing area may entail major risks. Regular inspection by neutral, independent experts from TÜV organisations as members of European Notified Bodies (NB) or Authorised Inspection Bodies (ZÜS) is essential for preventing incidents or accidents and for operating safely. The independent experts regularly issue status reports within first or recurring tests on systems or other technical facilities requiring supervision. They assess the risks for the plant compiled by the operator. Any defect found, which could entail risks for personnel, is recorded in a so-called test report. Conspicuous technical developments are discussed within Experience Exchange Groups. Within these groups, necessary measures for preventing any danger are determined.