GSN with safeTbox: A state-of-the-art Professional Tool for Safety Argumentation

In today’s rapidly evolving automotive and aerospace industries, ensuring system safety and regulatory compliance is critical. The need for more structured and clearer safety cases is required by existing and upcoming regulation and standards (e.g. AFGBV (German L4 law), EU ADS Implementation Act, ISO 26262, ISO 21448, ISO 21434, UL 4600, BSI PAS 1881). Complex systems, like autonomous vehicles, ADAS, and next-generation aircraft, require comprehensive safety assurance approaches. Goal Structuring Notation (GSN) is one of the most effective techniques for structuring, communicating and presenting safety arguments.

However, using informal tools such as spreadsheets and document editors to manage safety arguments is inefficient and error-prone. safeTbox offers a professional, integrated solution that supports GSN and facilitates the documentation and communication process. In this article, we’ll explore why safeTbox is the right tool to help you build safety cases and concepts.

GSN and Industry Standards

GSN visually maps safety arguments, showing how high-level goals are supported by strategies, sub-goals, and evidence. It’s invaluable in safety-critical domains, ensuring clear, defensible arguments for regulatory approval.

In the automotive industry, standards like ISO 26262 (functional safety) and ISO 21448 (safety of intended functionality) require structured safety cases. GSN is ideal for documenting these cases, especially in complex systems like autonomous driving. UL 4600 and PAS 1881 introduce additional detailed requirements for safety cases, requiring their continuous maintenance and update.

In the aerospace industry, standards like ARP4761 and DO-178C emphasize rigorous safety assessments. GSN links system designs, tests, and analyses to safety requirements, meeting regulatory demands while providing clarity to stakeholders.

Moving Beyond Informal Tools

Many organizations still rely on informal tools for safety argumentation (e.g. Visio). While these may work for smaller projects, they struggle with the complexity of modern automotive and aerospace systems, leading to inefficiencies, errors, and poor traceability between safety artifacts. In addition, cross-team communication, which is necessary to build and maintain a consistent system safety case is hardly possible with exchanging annotated PDF exports.

Why Choose safeTbox for Safety Argumentation?

1. A Professional Solution for Structured Safety Argumentation

safeTbox replaces informal tools with a professional platform that efficiently structures safety arguments in a clear and traceable manner. The tool’s modularization feature breaks down large arguments into manageable modules, ideal for complex systems.

safeTbox also allows the creation of reusable argumentation assets. Instead of starting from scratch, you can reuse modules across projects, saving time and ensuring consistency, particularly in projects with overlapping components (e.g., product lines).

2. Integrated Model-Based Solution with Automation and Traceability

Maintaining traceability between safety arguments and design artefacts is critical. safeTbox integrates with UML and SysML, ensuring traceability between design models and safety arguments. In addition, the artefacts of the safety lifecycle must be traceable. In particular, references to faults, safety requirements and verification and validation artefacts are of paramount importance. This is especially important for change impact analysis, which becomes more manageable with proper traceability.

3. Configurable for Different Use Cases

safeTbox is flexible enough for various safety argumentation applications, from documenting safety cases for certification to developing functional /technical safety concepts under ISO 26262.

Automotive professionals will find the tool particularly useful in the early stages of system design. It helps document safety concepts by allowing you to outline safety goals, refine them into functional and technical safety requirements, and then develop them into a more comprehensive safety case. This configurability makes safeTbox a valuable asset throughout the safety lifecycle.

safeTbox’s modeling automation speeds up the creation of GSN structures, reducing the cost and effort associated with manual safety case development.

4. User-Friendly and Efficient

One of safeTbox’s outstanding features is its focus on usability. It provides an intuitive interface that safety engineers can quickly adapt to, with advanced features that support modularization, multiple realization views, and semi-automated trace generation, giving you a lot of expressive power while saving you time and reducing the risk of missing critical links between the argument and design artifacts.

safeTbox is also highly configurable, allowing users to tailor the tool to specific project requirements, whether for specialized aerospace systems or general automotive safety cases.

5. Based on two decades of state-of-the-art applied research

In addition to providing a commercial implementation capable of documenting safety cases at an industrial level, the research team behind safeTbox has a history of working with industrial customers to address real-world, challenging reasoning problems in a variety of application domains. The knowledge we use to address these challenges has been built up through various research projects where we have worked and continue to work closely with the University of York, a major academic institution in the field, to develop practical solutions from the latest state-of-the-art research.

Recently, Fraunhofer IESE coordinated the creation of a reference safety argumentation structure for autonomous driving systems in the German flagship research project PEGASUS „V&V Methods“ (more information at https://www.vvm-projekt.de/final). For the immediate future, our main research focus in this context is to enable the systematic derivation of safety performance indicators for operational safety assurance from GSN safety cases, cross-team collaboration on a consistent system safety case, and stakeholder-centric argumentation views (e.g. different views for approval, certification, safety management, post-deployment monitoring).

Conclusion

In safety-critical industries like automotive and aerospace, structured and reliable safety argumentation is essential. safeTbox offers a professional solution, helping companies manage complex safety cases and concepts efficiently with the support of Goal Structuring Notation (GSN).

By moving away from informal tools and adopting safeTbox, you can reduce errors, save time, and ensure compliance with industry standards like ISO 26262 and ARP4761. With features like model-based integration, traceability, and automation, safeTbox is a must-have tool for safety professionals.