Next Generation Data Interoperability: It's all About the Metadata

Data interoperability has been an objective of the DoD for as long as automated systems have been in existence, particularly in the area of Command and Control (C2). Long time DoD efforts to achieve data interoperability through data element standardization were not successful, and these efforts have been superceded by the 2003 DoD Net-Centric Data Strategy. This approach seeks to capitalize on successes in the commercial IT sector through the use of web-based technologies and the concept of Service Oriented Architecture (SOA). The key to this approach is the metadata that describes the data and services being shared. Several DoD Communities of Interest (COI) are now producing and publishing metadata artifacts in the DoD Metadata Registry. Programs of Record participating in these COIs are also beginning to use these artifacts to expose their data via web services in various experiments and exercises. While the current approach will ultimately make data visible and accessible to the enterprise, the data is currently only truly understandable and interoperable within the COI. Data understanding and interoperability across COIs remains a manual, ad-hoc process, and "on-the fly" machine-to-machine data interoperability and composition of services is not supported. In order to improve current efforts to implement the DoD Net-Centric Data Strategy and move toward the level of interoperability that is required for dynamic data exchange and composition of services, it is necessary to rethink how metadata is defined, organized, and managed. This paper proposes an approach for "next-generation" implementation of the DoD Net-Centric Data Strategy that includes a comprehensive metadata repository exposing all the details of the data's definition and the mapping of this data through the systems that generate the standardized transactions. Specifically, an ISO/IEC 11179-3 compliant Metadata Registry with COI efforts directed toward producing metadata products consistent with this standard is endorsed, with the metadata registry artifacts integrated into a distributed and federated metadata repository environment. Application to Joint C2 capabilities and implications for M&S, a key aspect of C2, are also discussed.