This Technical Specification has three sections, 1) general considerations of design and deployment, 2) data aggregation and data modelling and 3) architecture and technology, and is intended to provide an overall set of guidelines for clinical data warehouse deployment supported by useful descriptions concerning different data aggregation and modelling approaches as well as particular aspects of information architecture that contribute to successful deployment. The first section is of particular interest to healthcare decision-makers, including information technology managers, of requirements and procedures that support successful clinical data warehouse deployment. The second section supports the understanding, choice, instigation and evaluation of methods that ensure reliable selection and aggregation of primary data for adequate compilation and presentation to support decisions – this section is of particular interest to statisticians, epidemiologists, healthcare evaluation specialists and others. Section three is of particular interest to informaticians concerned with efficient architectures, data mining methods, dynamic data querying and visualization for clinical data warehouses.