The Defense Department has defined three interrelated
architectures for C4I systems: the Joint Operational Architecture, the Joint
Systems Architecture, and the Joint Technical Architecture (Box
2.9). The Joint Operational Architecture is intended to identify mission objectives, information exchange requirements, and logical connectivities among and within command and control units or organizations. The Joint System Architecture is intended to map these information exchange requirements to specific hardware and software systems and to specify capacity and performance constraints. The Joint Technical Architecture identifies and mandates standards and identifies standards-compliant products, when available, for the building of systems and subsystems so as to promote interoperability between them.
The architectures are not all at the same level of
development; the Joint Technical Architecture (JTA) is by far the most mature of
the three. Wherever possible, the JTA references commercial standards, products,
and technologies. The JTA is intended to provide a set of correct and mutually
consistent technical standards, application interfaces (APIs), and protocols,
along with decision rules for using them. The scope of the JTA is broad,
encompassing systems for C4I, sustainment, weapons and platforms, and modeling
and simulation. By conforming to the standards, products, and implementing
guidance codified in the JTA, such systems are intended to be "born joint," in
accordance with Chairman of the Joint Chiefs of Staff Instruction 6212.01A.19
The Joint Technical Architecture also provides an important foundation for coping with unforeseen requirements. The investment in the basic level of interoperability that is offered by building systems in compliance with the Joint Technical Architecture establishes a defense-wide fundamental level of interoperability, which permits a much more rapid accommodation to new scenarios and operational requirements than would be possible without it.
As far as the committee has been able to determine, the
Joint Operational Architecture was originally intended to be a construct
covering all military operations. For example, the 1998 Annual Report of the
Secretary of Defense states that "the DOD is developing an agency-wide Joint
Operational Architecture that describes the tasks and activities, operational
elements, and information flows required to accomplish or support the missions
of the DOD."20 The Information
Superiority Campaign Plan of the Joint Chiefs of Staff calls for "the
development of a high-level, C4 Joint Operational Architecture that integrates
the joint warfare functions, from national level through operational level, into
implementations of the JV2010 [Joint Vision 2010] operational concepts."21
DOD architectural development to date, which has focused on the Joint Technical Architecture--conformance to a "building code" and standards--is, as DOD recognizes, in and of itself insufficient to ensure technical C4I interoperability, since it fails to address some of the most important architectural elements required for interoperability. Many critical architectural elements, not yet developed, would be contained within the yet-to-be developed Joint Systems and Joint Operational architectures. Used in combination, these would define interoperability requirements to support operational mission information flows. For example, the Operational Architecture and Systems Architecture for a particular operational activity would define which service-developed systems would have to exchange what information over what media in what format.
The committee recognizes that development of the Joint Technical Architecture was a pragmatic first step to take, given that establishment of technical standards is much easier than establishment of an operational or systems architecture. The definition of information flows and data semantics required for operational or systems architectures is inherently complex, and additionally, provokes debate about how operations are to be conducted.