Joint Common Architecture (JCA) Recommendations

In June of 2013, the Army released a draft overview of the Joint Common Architecture (JCA) model (Ref. 1), which suggests a way to decompose mission systems functionality into Domains, Subsystems, and Components. This paper offers additional recommendations to the structure of the JCA, including an added Systems decomposition layer and Vehicle Management Systems (VMS) functionality related to flight controls. The new Systems layer bridges the connection between the Domains and Subsystems provided in the draft JCA. The structure of the Systems layer encourages the mission systems integrator to conduct design trades allowing functionality to span more than a single Subsystem. The Systems layer recognizes advancements in technology to enable more processing to be done within single enclosures, and the trend among subsystem providers to offer more functionality within their products. It balances the decomposition gap between the broad Domain areas and numerous Subsystems into a partition of Systems that naturally fit the major systems that need to be developed for rotorcraft aviation platforms. Partitioned operating systems (e.g., those real-time operating systems conformant with the Future Airborne Capability Environment), processes for critical software development (e.g., DO-178C), and virtual machines allow mixed criticality levels of software to execute inside the same processing environment. Such implementations are flight certifiable allowing for the opportunity to incorporate flight controls functionality within the Joint Common Architecture. Flight-critical domain components and functions continue to be within the JCA, with design characteristics conforming to flight critical requirements. This approach offers sensor and processing consolidation that yields savings in space, weight, power and cost.