OntoGSN: An Ontology-Based Framework for Semantic Management and Extension of Assurance Cases

TL;DR

The paper presents OntoGSN, an ontology-based framework that bridges semantic gaps in Goal Structuring Notation (GSN) assurance cases by providing a 1:1 OWL/SWRL/SPARQL formalization of GSN v3, plus browser-based middleware and a client interface. It delivers a three-layer architecture (Ontological Core, Middleware, Interface) with a detailed core of axioms and rules, extensible patterns, and modules for scalable AC management. The work is publicly available and evaluated against FAIR, OOPS, and competency questions, with dynamic examples illustrating adversarial robustness and vehicle safety scenarios. OntoGSN aims to enable interoperable, machine-readable reasoning for safety- and security-critical assurance, supporting ongoing maintenance, tool integrations, and cross-domain adoption.

Abstract

Assurance cases (ACs) are a common artifact for building and maintaining confidence in system properties such as safety or robustness. Constructing an AC can be challenging, although existing tools provide support in static, document-centric applications and methods for dynamic contexts (e.g., autonomous driving) are emerging. Unfortunately, managing ACs remains a challenge, since maintaining the embedded knowledge in the face of changes requires substantial effort, in the process deterring developers - or worse, producing poorly managed cases that instill false confidence. To address this, we present OntoGSN: an ontology and supporting middleware for managing ACs in the Goal Structuring Notation (GSN) standard. OntoGSN offers a knowledge representation and a queryable graph that can be automatically populated, evaluated, and updated. Our contributions include: a 1:1 formalization of the GSN Community Standard v3 in an OWL ontology with SWRL rules; a helper ontology and parser for integration with a widely used AC tool; a repository and documentation of design decisions for OntoGSN maintenance; a SPARQL query library with automation patterns; and a prototypical interface. The ontology strictly adheres to the standard's text and has been evaluated according to FAIR principles, the OOPS framework, competency questions, and community feedback. The development of other middleware elements is guided by the community needs and subject to ongoing evaluations. To demonstrate the utility of our contributions, we illustrate dynamic AC management in an example involving assurance of adversarial robustness in large language models.

Figures (7)

• Figure 1: Example AC fragment for a rocket launch system, adapted from Whitman et al. (2020; whitman2020artemis) and paraphrased.
• Figure 2: Graffoo falco2014graffoo diagram of Core GSN.
• Figure 3: Argument Pattern Extension
• Figure 5: Confidence Argument Extension
• Figure 8: Document panel