The Data Centre Services (DCS) Reference Architecture Document (RAD) has been developed to describe the reference architecture models for a common, shared and consolidated DC environment for the Government of Canada (GC) as an enterprise. The DCS RAD defines the end-to-end architectural model and the components that will form the basis for developing the Shared Services Canada (SSC) target end-state DC services for the Data Centre Consolidation Program (DCCP). The architecture will support the delivery of DCCP services for SSC's partner organizations over the near term (less than three years), with an evolutionary capability to encompass a hybrid cloud service delivery model for long-term strategic planning.