In October 2016, at the CIS Annual General Meeting in Frankfurt, the IEC, which publishes the vast majority of international standards for electrical and electronic appliances and systems, and CENELEC, their counterpart at European level, signed the Frankfurt Agreement, which will strengthen harmonization between international and European standards. In order to avoid duplication between standardisation at international and European level, to the benefit of standard contributors and users, 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 Organisation for Standardisation (ISO) and the International Electrotechnical Commission (IEC). define the rules of cooperation. The Vienna Agreement, signed in 1991 between CEN and ISO, recognises the primacy of international standards and aims to ensure that standards are recognised simultaneously at international and European level by improving the exchange of information and mutual representation at meetings. Either CEN or ISO take the lead in the development of a new standard and the relevant documents must be submitted for simultaneous approval. ISO members can thus influence the content of the CEN standard and vice versa. Around 31% of CEN standards are developed under the Vienna Agreement. Nevertheless, the Vienna Agreement allows 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 has an important strategic role to play in monitoring the implementation of the Vienna Agreement and advising the CEN Higher Technical Council and the ISO Technical Management Committee on all matters related to the Vienna Agreement, i.e. the need for revisions. In September 2001, a revised version (version 3.3) of the Vienn Agreement was published, in which the agreement itself was reduced to the essential principles of cooperation BETWEEN ISO and CEN. Overall, the current version gives priority to international standardization and gives ISO management greater importance than previous versions. For example, EN-ISO standards can only be revised under the guidance of ISO, regardless of their origin.

In 1996, CENELEC and the IEC signed the Dresden Agreement in order to create the necessary framework for an intensive consensus process between European and international standardization activities in the electricity sector. In order to avoid duplication between standardization at international and European level, to increase the effectiveness of standardization at European and international level, CEN and CENELEC have signed agreements with their respective international partners, the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC). define the rules of cooperation. The technical cooperation agreement between ISO and CEN (Vienna Agreement) is a technical cooperation agreement between ISO and the European Committee for Standardization (CEN). It was adopted on 27 The Administrative Council of CEN, meeting in Geneva on 16 and 17 May 1991 on 16 June 1991 in Vienna, was formally approved by the Governing Body of CEN, following its approval by the Executive Board of ISO on 16 and 17 May 1991, and replaced the Agreement on the exchange of technical information between ISO and CEN (Lisbon Agreement), concluded in 1989. . .