2023 Year in Review
Extending SysML V2 with AADL Concepts to Support Engineering and Certification of Safety-Critical Systems
Department of Defense (DoD) program offices and defense industrial base vendors employ model-based systems engineering (MBSE) practices to engineer complex embedded systems architecture and reduce safety and security risks through early analysis. Both the Architecture Analysis and Design Language (AADL) and the Object Management Group’s (OMG’s) Systems Modeling Language (SysML) support this effort by providing engineers with the ability to develop architectures, conduct reviews, and perform analysis. SysML Version 1 focuses on systems engineering, traceability, and system decomposition and refinement. AADL focuses on the precise evaluation of performance and safety metrics.
Defense developers need to use both SysML and AADL in their MBSE efforts, but using two languages is challenging and entails significant, unsustainable costs in both training and maintenance. With the upcoming release of SysML Version 2, the SEI is spearheading the effort to combine SysML’s capabilities to describe complex systems and AADL’s analysis capabilities. The work will bridge the gap between the two languages through a refinement of SysML V2 concepts that align with AADL V2, delivered as a SysML V2 library.
The expected impact is in having a single way to model systems by reducing the number of languages required, while preserving the semantics and analysis capabilities of AADL.
Jérôme HuguesSenior Architecture Researcher, SEI Software Solutions Division
Jérôme Hugues, principal architecture researcher at the SEI, noted, “The expected impact is in having a single way to model systems by reducing the number of languages required, while preserving the semantics and analysis capabilities of AADL.”
This work will also reduce the effort required for the DoD to design safety-critical systems using SysML V1. Limited by SysML V1’s semantics, the DoD currently uses SysML profiles and translation tools to refine SysML models into AADL ones and continue design activities. But the approach of using multiple tools and iterations is slow and error prone and requires engineers to have additional expertise. With leaner syntax and semantics, as well as extensibility mechanisms, SysML V2 provides an opportunity to better integrate AADL concepts directly into a single language, which will ease the engineer’s learning curve.
The SEI has developed a proof-of-concept extension of SysML V2 with AADL V2 capabilities, leveraging both SysML V2 and KerML libraries. Hugues and Gene Shreve, a systems engineer with Integration Innovation, Inc., have also recently established a working group as part of the newly formed OMG Systems Modeling Community (SMC) to further this effort. The working group will compare SysML V2 and AADL semantics and modeling styles, align semantics and define mapping rules between both languages, develop specific KerML/SysML library elements to support real-time-embedded and safety-critical system design and development, and define use and test cases to validate the library.
The working group’s contributions will support the precise engineering of safety-critical, real-time, embedded systems and allow for code generation as well as verification and validation.
The DoD will benefit from having a single-language approach covering both high-level MBSE and low-level safety-critical embedded systems and precise semantics leveraging SysML V2 extensible semantics capabilities. Developing a common tool set built across the SysML V2 open application programming interface, the SEI-led working group will support the DoD’s Digital Engineering Strategy to promote the use of digital representations of systems and components and the use of digital artifacts to design and sustain national defense systems.
Photos: Alice de Casanove; Senior Airman Mitchell Corley, U.S. Air Force
RESEARCHERS
Mentioned in this Article
Architecture Analysis and Design Language (AADL)
Systems Modeling Language (SysML)
DoD Digital Engineering Strategy
