Model-based systems engineering (MBSE) tools lead to standardization that open architectures rely on for collaboration, innovation, and re-use of models leading to program cost savings. We asked some VITA community members:

How is model-based system engineering affecting the use of open standards in the open systems ecosystem?

Dean Holman, President & Executive Director, VITA

The Office of the Under Secretary of Defense for Research and Engineering issued directive 5000/97 in December 2023 mandating Digital Engineering methodologies across the life cycle of new DoD programs. This includes model-based systems engineering (MBSE). By requiring specific model requirements to be included in proposal packages, Program Managers can more reliably compare competing solutions to ensure they meet the goals of the system. There are multiple levels of detail that must be managed in the endeavor. At the simplest level, VITA is proactively creating spreadsheets containing the individual rules, recommendations, observations, permissions, suggestions and verification methods written in our Open Standards.

There is another more complex level of information which is much more difficult to encode in a digital model due to the wealth of data currently encoded in figures and tables within standards. Humans work well with these highly visual mechanisms for specifying extensive amounts of data. Mechanical drawings and connector pinout maps are two such examples. Finding or developing tools for encoding all that data into a digital model represents a huge challenge. As encoding capabilities improve, the fidelity of digital models will continue to improve as these highly dense characteristics make their way into the MBSE models.

While the benefits that MBSE can bring to the development and support of next generation systems, climbing that capabilities curve will take substantial effort and cross-domain expertise from all involved. VITA stands ready to participate in these efforts.

From: Taymor Kamrany, Capture Director, Mercury

Models serve as the authoritative source of integrating system architecture across multiple domains using industry open standards. Mercury has captured material from open standards such as OpenVPX and SOSA within our MBSE ecosystem as set of stakeholder requirements. The information is leveraged/reused by multiple product models to form traceable and executable requirements and verification methods for product development. The base models help ensure compliance to the open standards within our product families. This approach reduces product development time and cost. While Mercury captured these standards previously on our own, groups like SOSA are in the process of developing a model for the standard that will be available for adopters and overtime bring additional value like simulation to the model.

MBSE ecosystems provide improved traceability between design decisions and the ability to meet higher-level requirements, like system security. Systems that incorporate complex anti-tamper and/or cyber policies benefit from the improved traceability and the decision-making enablement MBSE affords to trade the security needs with/against other customer-driven needs like MOSA aligned interoperability. Mercury BuiltSECURE product development processes employ MBSE for this purpose at product definition to produce industry-leading, open standards aligned, secure processing solutions.

From: Jason Holmstedt Sr. Director, Technology and Innovation, Intellisense Systems Inc.

We are seeing model-based systems engineering (MBSE) become increasingly utilized in defense systems development and acquisition. Traditionally, documents have played a key role in conveying requirements and interface definitions as the source of truth for systems development. This has involved extracting standards content using requirements management tools or manually translating relevant information for use in systems engineering for flow down to detailed design activities. However, the paradigm shift to MBSE allows the model to digitally represent the contents of the standard and even serve as the source of truth itself.

This paradigm shift offers significant advantages including direct traceability to the standard from the higher-level system model and capturing interdependencies between standards requirements. For example, rather than treat individual standards as discrete sets of requirements the interactions and mapping between them can be captured. For example, how the VITA 62 power supply standard maps to the VITA 46 VPX standard. Beyond simply capturing requirements of a standard the model enables capturing block diagrams and activity diagrams. Block diagrams support capturing interface definitions that can tie directly to implementation options such as slot profiles and specific pin attributes including protocol, voltage levels, and current limits rather than figures and tables in the document. Activity diagrams can help convey processes or state management. In the context of VITA 46 this could include how discrete signals such as SYSRESET are used and how the system behaves in response to the signal being asserted. In this manner, the diagrams convey visually the intent of the requirements rather than derived from textual descriptions. Lastly, mitigating the disconnect between documents and systems engineering outputs can significantly help support design verification and generate conformance artifacts.

The opportunities for MBSE are incredibly exciting and there is quite a bit of work ahead to determine the role standards such as those established under VITA will play in this transformation.