1 Introduction
Some of the most significant challenges today in the US Department of Defense (DOD) are in the design, integration, upgrade, and maintenance of information systems, particularly for Command, Control, Communications, Computers, and Intelligence () [11]. As the tactical emphasis in the DOD shifts from platform-centric toward network-centric warfare, the issues in information systems integration, interoperability of new and legacy systems, data mining, aggregation, standardization, and reuse become more important. Similarly, the need for efficient, cost effective, technical solutions becomes more urgent.