The Technical Cooperation Agreement between ISO and CEN (Vienna Convention) is a technical cooperation agreement between ISO and the European Standards Committee (CEN). After being formally approved by ISO`s Executive Board at its meeting on 16-17 May 1991 in Geneva on 27 June 1991 by the NEB Board of Directors, it replaced the technical information exchange agreement between ISO and CEN concluded in 1989 (Lisbon Agreement). Vienn`s “codified” agreement was approved in 2001 by the ISO Board and the NEEC Board of Directors. In October 2016, the IEC, which publishes the vast majority of international standards for electrical and electronic equipment and systems, and CENELEC, their European equivalent, signed the Frankfurt Agreement, which will strengthen harmonisation between international and European standards. Nevertheless, the Vienna agreement allows the CEN or ISO to carry out standardisation activities on the same subject if deemed necessary. The Joint ISO-CEN Coordinating Group of the Technical Boards plays an important strategic role in monitoring the implementation of the Viennese Agreement and consulting with the CEN`s Senior Technical Committee and the ISO Technical Technical Committee on all matters related to the Viennese Agreement, including the need for revisions. In September 2001, a revised version (version 3.3) of the “Vienna” agreement was published, which reduced the agreement itself to the essential principles of cooperation between ISO and the NEC. Overall, the current version of international standardization gives priority and gives more importance to ISO leadership than previous versions. For example, ISO standards can only be revised under ISO`s direction, regardless of their origin. In 1996, CENELEC and the CIS signed the Dresden Agreement to create the framework for an intensive consensus process between the development of European and international standards in the electricity sector. In order to avoid duplication between de-derisation at international and European level, to the benefit of contributors and users of standards, as well as to improve the effectiveness of standardisation at European and international level, CEN and CENELEC have signed agreements with their respective international partners, the International Standards Organisation (ISO) and the International Electrotechnical Commission (IEC) on the rules of cooperation.
The Viennese Convention, signed in 1991 between the CEN and ISO, recognises the primacy of international standards and aims to simultaneously recognise standards at international and European level by improving information exchange and mutual representation at meetings. Either the NEEc or ISO take the lead in the development of a new standard and the related documents are submitted by both parties for simultaneous approval. This allows ISO members to influence the content of the CEN standard and vice versa. About 31% of the CEN standards are developed under the Viennese Convention. In order to avoid duplication between de-derisation at international and European level, to the benefit of contributors and users of standards, as well as to improve the effectiveness of standardisation at European and international level, CEN and CENELEC have signed agreements with their respective international partners, the International Standards Organisation (ISO) and the International Electrotechnical Commission (IEC) on the rules of cooperation. The CEN was founded in 1961. The 34 national members are working together to develop European standards in different sectors, to build a single European market for goods and services and to position Europe in the global economy. The CEN is officially recognised by the European Union as a European standards body; other official European standards bodies are the European Electrotechnical Standards Committee (CENELEC) and the European Institute of Telecommunications Standards (ETSI).   The CEN (in conjunction with CENELEC) has a voluntary quality label for products and services.