TOWARDS A SYSTEMS ENGINEERING ONTOLOGY STACK

Abstract

Semantic Web Technologies (SWTs) provide an approach to the structuring and understanding of data. SWTs utilize ontologies, reasoners, and query languages to structure existing knowledge, validate knowledge, and infer new knowledge. Ontologies in particular play a central role in enabling reusability and interoperability between domains. A common way to organize ontologies and their dependencies is in a layered ontology stack. These layers often incorporate top-level, core and domain ontologies. Libraries of standard instances can also be used. Federating the conceptualization of a domain across upper- and lower-level ontologies improves the reusability of higher-level terminology in other domains, and therefore improves interoperability between them. The University of Arizona Ontology Stack (UAOS) is a layered, modular ontology stack that has been developed to support digital engineering activities at the University of Arizona. It is based on the Basic Formal Ontology (BFO), and currently comprises five core ontologies and 12 domain ontologies. The UAOS reuses existing ontologies and standards wherever possible. The core ontologies, for example, are based on the Common Core Ontologies, developed at CUBRC, and the Provenance Notation (PROV-N), a W3C standard. Domain ontologies include the System Architecture Ontology, based on ISO 42010, and the Orbits and Trajectories Ontology, based on CUBRC's Space Object Ontology. In this paper, we report on the development of the UAOS, present examples of how it has been used to support digital engineering research, discuss the challenges of integrating ontologies from multiple sources into a cohesive stack, and highlight topics of interest for future research.