Bridging the Semantic Web and Systems Engineering: OML in practice

I’m happy to say that our paper ‘Bridging the Semantic Web and Model-Based Systems Engineering with the Ontological Modeling Language’ was accepted at the International Semantic Web Conference (ISWC 2026). The paper is by Maged Elaasar (Modelware), me, Eduard Kamburjan (IT University of Copenhagen and University of Oslo), Mohammad Hamdaqa (Polytechnique Montréal), and Abdelwahab Hamou-Lhadj (Concordia University).

As in the title, the paper is intended to bridge the semantic web (SW) and model-based systems engineering (MBSE) communities. While SW principles have been used in MBSE for some time, we still see challenges. The paper thus has three main points:

1. identify these challenges: that ontological languages such as OWL are not the proper level of abstraction for describing SE, and that there is a lack of robust ontological modelling tools for engineers
2. discuss how OML and the openCAESAR framework address these challenges
3. report on how OML and openCAESAR are used in practice, with some discussion of reported benefits and drawbacks

We hope that this work is useful to the semantic web community in understanding the perspectives and requirements of the systems engineering community, as discussed below. We look forward to discussions about what needs to change on both sides such that the power of the semantic web can help in the development of complex systems.

An author pre-print is available here. Related work of ours includes openCAESAR: Balancing Agility and Rigor in Model-Based Systems Engineering on the toolchain, and a survey of practitioner experiences in model-based systems engineering. OML itself, with tutorials, is at opencaesar.io.

Two challenges for the semantic web in systems engineering

We claim that ‘the languages and frameworks currently used for ontology engineering are not suited to be integrated in MBSE workflows’. This is based on two broad challenges:

1. ontological languages such as OWL are not the proper level of abstraction for describing SE.
   • Engineers wish to rely on well-known patterns (composition, aggregation)
   • They also wish to reason about their system in a closed-world form, with a clear interface to an open-world.
2. There is a lack of robust ontological modelling tools suited for experts used to textual and modular languages.
   • “Protégé requires significant experience in knowledge representation and semantics”.
   • Other tooling requires alignment with upper ontologies, which can hamper the velocity of system development

We thus argue in the paper that OML provides a suitable layer above OWL, such that engineers can have the benefits of the semantic web (interoperability, ontological reasoning) while still matching MBSE practice requirements (modularity, textual syntax), and that openCAESAR provides suitable tooling for practice (CI/CD, Maven versioning, textual editor).

OML in practice

We report on a few examples of OML and openCAESAR use in practice. For example, at JPL, an ontology was created in OML to provide consistency and semantic checks for spacecraft electrical wiring. This replaced an error-prone Excel spreadsheet. At JAXA, OML was used as a semantic backbone for spacecraft orbital analysis, shrinking the time required for analysis from weeks to hours. At Leonardo UK, OML vocabularies were used as the common ontology to bridge the data formats and semantics of separate avionics tools.

In academia, we mention the work by others on modelling validity frames, and our own work on using OML in the modelling of Digital Twins, such as DTInsight.