Historically, military aviation software systems have been developed, procured, and implemented by a single vendor with platform-specific designs. This stovepipe development process has had some undesired side-effects including long lead times, cumbersome improvement processes, and lack of hardware and software reuse. This combined with complex mission equipment and electronics systems, extensive testing, and airworthiness qualification requirements have caused a significant increase in the cost and schedule impacting the ability of the military aviation community to deploy new capabilities in a timely manner.
The FACE Technical Standard tackles barriers to modularity, portability, and interoperability by defining a Reference Architecture and Data Architecture, employing design principles to enhance software portability, using industry standards for distributed communications, programming languages, graphics, operating systems, and other areas as appropriate, and outlining conformance requirements.
The FACE Reference Architecture defines a layered architecture composed of five segments connected by three interfaces (aka as “Key Interfaces” per a MOSA). Add Graph Here
The five (5) segments:
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Operating System Segment (OSS): where foundational system services used by all the other segments and vendor-supplied code reside
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Input/Output Services Segment (IOSS): where normalization of vendor-supplied interface hardware device drivers occurs
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Platform-Specific Services Segment (PSSS): comprised of software components providing platform-specific capabilities and/or interactions with device services.
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Transport Services Segment (TSS): comprised of communication services
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Portable Components Segment (PCS): comprised of software components providing capabilities and/or business logic and intended to remain agnostic from hardware and sensorsThe three (3) FACE key interfaces are:
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Transport Services Interface: provides a standardized means for software to use communication services provided by the TSS, and the FACE Data Architecture governs the representation of the data traversing the Transport Services Interface
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Operating System Segment Interface: provides a standardized means for software to utilize the services within the operating system and other capabilities related to the OSS
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I/O Services Interface: provides a standardized means for software to communicate with device drivers
The FACE Data Architecture is a set of related models, specifications, and governance policies with the primary purpose of supporting an interoperable means of data exchange. It leverages the Open Universal Domain Description Language (Open UDDL) to define the FACE Shared Data Model (SDM) and Unit of Portability (UoP) Supplied Models (USM). The SDM is a repository of data elements which allows standardized definitions to be used across all FACE conformant data models. The Data Architecture also defines the rules of construction of the USM and the FACE Data Model Language, specified by an Essential Meta-Object Facility (EMOF) metamodel and a set of Object Constraint Language (OCL) constraints.
The FACE Conformance Program provides the associated conformance criteria and processes necessary to assure Units of Conformance (UoCs) are developed according to the FACE Technical Standard. The FACE Conformance Program consists of Verification, Certification, and Registration. The FACE Consortium has established a FACE Conformance Program and defined an associated Conformance Policy for the FACE Technical Standard.
