Military Embedded Systems

The Future Airborne Capability Environment (FACE) approach is a government/industry initiative, managed by the FACE Consortium under the auspices of The Open Group. Its goal is to reduce software development/deployment costs through source code portability and reuse and thereby avoid vendor lock-in. A key element of the FACE approach is an official process and test suite for verifying that software conforms to the requirements specified in the FACE Technical Standard. However, this process currently does not easily accommodate Ada, a language with a long history of successful usage in safety-critical airborne systems, both military and commercial. There is a solution to this hurdle, however: a practical approach to FACE conformance verification for Ada code (both Ada 95 and Ada 2012), in particular for software that is not part of the underlying operating system.

The FACE [Future Airborne Capability Environment] approach to reducing life cycle costs for the military is based on reusing software components across different platforms and airborne systems. The FACE Technical Standard addresses this issue through a reference architecture and data model, well-defined interfaces, and widely used underlying industry standards (IDL, Posix, ARINC-653).

Airborne systems that need a small footprint or must comply with an industry assurance standard such as DO-178B [1] or DO-178C [2] are sensitive to size and complexity costs in the run-time support libraries. To answer these needs, the Future Airborne Capability Environment (FACE?) Technical Standard [4] has designated the Ravenscar subset of the Ada programming language?s tasking features as one of the acceptable concurrency approaches for a software component that must satisfy safety and/or security assurance requirements.

Defense platforms are expected to perform over a long operational life that can span several decades. Developing high-reliability, safety-critical software that is built to last requires comprehensive tools from trusted industry partners. Robust software-development solutions can help engineers design and develop new long-life unmanned systems and can enable upgrade of systems on currently fielded unmanned platforms to extend their life cycle.

The FACE [Future Airborne Capability Environment] approach is a joint government-industry software standard and business strategy for acquisition of affordable software systems that promotes innovation and rapid integration of portable capabilities across global defense programs. FACE - originally avionics-focused only, but has now broadened to encompass a wide catalog of applications for use across the entire spectrum of real-time systems - does not directly address issues of quality or fitness for purpose. Because these traits are obviously important in practice, the natural question for component developers is how to meet both the explicit FACE objective of portability and any domain-specific requirements for software reliability, safety, and security. Part of the answer is to choose appropriate software-development technologies and language(s).

DO-332, the DO-178C standard's supplement on Object-Oriented Technology (OOT) and related techniques, analyzes the issues raised by object orientation in safety-critical software and supplies new guidance to deal with OOT's vulnerabilities. An important new objective of DO-332 is "Local Type Consistency Verification," which exploits a type theory result known as "the Liskov Substitution Principle" and helps address some of the key certification challenges raised by OOT's dynamic flexibility.

The new avionics software safety standard DO-178C, along with its supplemental Software Tool Qualification Considerations (DO-330), has clarified and expanded the tool qualification guidance provided in DO-178B. The challenge of maintaining qualification-ready tools throughout a system?s evolution can be expedited through an approach based on agile development principles.