Putting the O in Model - Ontologies for MBSE

With origins in antiquity and ancient philosophers speculating on the nature of being, “ontology” and “ontological modelling” perhaps have a reputation for being esoteric, impenetrable and only for the purist of academics. In the last couple of decades, however, great work has been done to make ontological concepts and models readily accessible, along with the essential toolkits required to apply them at a practical level.<br/>During system development, and especially with Model-Based Systems Engineering (MBSE), it is essential to conceptualise the world that the system will inhabit, and this involves developing and structuring concepts, terms and their relationships. An ontology is an explicit specification of a conceptualizsation and provides the foundation for MBSE and architecture descriptions. Stronger foundations support longer-lived models that work better together. Increasingly, ontologies are also being recognised as essential for enterprise knowledge systems, interoperable standards and explainable Artificial Intelligence (AI).<br/>This paper, from the Safety Critical Systems Club (SCSC) Ontology Working Group (OWG), introduces modelling with ontologies. Examples show different ways to model aircraft flights and how this can affect interoperability. The examples use the Unified Foundation Ontology (UFO) and the OntoUML modelling language based on UFO and UML. The authors consider the importance of different perspectives and capturing these in our modelling and show the types of challenge a top-level ontology can help with. This demonstrates how relevant and important ontologies are for enhancing collaboration and understanding between stakeholders and the models they use.<br/>The paper concludes by outlining the OWG’s objectives for developing ontological models that will benefit everyone working in domains that involve understanding risk, such as safety and security.