This document: describes the general principles for data centres upon which the requirements of the EN50600 series are based; defines the common aspects of data centres including terminology, parameters and reference models (functional elements and their accommodation) addressing both the size and complexity of their intended purpose; describes general aspects of the facilities and infrastructures required to support data centres; specifies a classification system, based upon the key criteria of “availability”, “security” and “energyefficiency” over the planned lifetime of the data centre, for the provision of effective facilities and infrastructure; details the issues to be addressed in a business risk and operating cost analysis enabling application of the classification of the data centre; provides reference to operation and management of data centres; introduces the concepts of Key Performance Indicators (KPIs) for resource management of data centre facilities and infrastructures. The following topics are outside of the scope of this series of European Standards: the selection of information technology and network telecommunications equipment, software and associated configuration issues are outside the scope of this European Standard; quantitative analysis of overall service availability resulting from multi-site data centres; safety and electromagnetic compatibility (EMC) requirements (covered by other standards and regulations. However, information given in this European Standard can be of assistance in meeting these standards and regulations).