Any integrated set of policies, procedures, rules, criteria, tools and verification instruments and mechanisms that together ensure and improve the quality provided by a VET institution. Comment: "approach" is used as an overall term because the term "system" is often used in a narrower sense. "Approach" covers both very fixed and formalised real systems and any sets of more systematic behaviour meant to regulate and/or to develop the quality performance of a VET system. Source: Cedefop, Christensen and Bertzeletou, 2001. Source: Glossary Quality in education and training, Cedefop. Luxembourg: Publications Office of the European Union, 2011.