1. The Generic Statistical Information Model (GSIM) provides a common language for describing the information objects relevant to the statistical production process. Having a common language increases the ability to compare information within and between statistical organizations. The Common Statistical Production Architecture (CSPA) is a reference architecture for the official statistics industry, providing the blueprint for designing and building statistical services in a way that facilitates sharing and easy integration into statistical production processes within or between statistical organisations

2. At a sprint session held in Ottawa in February 2015, participants concluded that the gap between the conceptual nature of the GSIM and the practical implementation focus of the CSPA was too wide. To bridge this gap, a new layer, a Logical Information Model (LIM), was needed. The aim of the LIM is to help developers of CSPA-compliant services by translating the conceptual GSIM information objects into physical specifications of the information that flows in and out of statistical services.

3. LIM refines the conceptual definitions from GSIM, and describes the information objects and logical relationships required to support a CSPA service, in a manner which is consistent with GSIM and independent of the terminology used in existing standards such as SDMX (Statistical Data and Metadata eXchange)

and DDI (Data Documentation Initiative)

. It supports consistent use of SDMX, DDI and other implementation standards in reusable CPSA services, whilst also making it easier for any organisations that do not use SDMX or DDI to implement CSPA-compliant services.

4. One of the requirements for a CSPA Service to be included in the CSPA Statistical Service Catalogue is that it is compliant with the architecture and it is specified using the LIM.

5. A pragmatic approach has been followed during the development of the LIM. Only those parts actually needed by CSPA Services during 2015 being developed during that year. Other parts will be worked on as and when needed. The LIM is designed in accordance with the LIM Design Principles (outlined in Annex1).The scope of the LIM, and the current state of development at the end of 2015 are illustrated in the following table. The remainder of this document describes the parts of LIM that have been developed so far.