Developing safety-critical systems places high demands on freedom from faults and robustness. For the required certification, extensive nominal and robustness tests are needed at both system and component level. Existing test case generation approaches are reaching their limits: at the system level, the derivation of tests is difficult due to emergent behavior, while automated test case generation at the component level involves high computational complexity. Manual testing on low levels is also labor-intensive and error-prone, complicating seamless traceability to system requirements.
Integrating advanced methods into the development process
To identify faults in safety-critical systems early and efficiently, fortiss—as part of the PlaTFoRm project (Practical Testing of Formal Requirements)—is working with Verified Systems International GmbH (Germany), D-Risq Ltd, and Newcastle University (United Kingdom) to develop innovative solutions for validating system requirements. These solutions allow high-level requirements to be formulated in a formal yet intuitive language, from which preconditions and postconditions are automatically extracted. Based on this, heuristic case test generation is enabled, reducing computational effort and targeting worst-case scenarios.
Researchers from the fortiss Competence Field for Model-based Systems Engineering are focusing on two core aspects to effectively integrate advanced methods like formal methods and (co-)simulation into the development process. First, the project aims to develop a framework for simulation-based robustness testing at the system level. This framework allows safety-relevant properties to be verified early in development, including the injection of software and hardware faults to test safety mechanisms. Second, the project is working on automated heuristic test case generation methods to enable rapid and targeted identification of test cases that can reveal potential faults within an integrated system. The generation of test cases is based on system-specific heuristics that are derived from formal requirements.
In both cases, the goal is to enable engineers to use these technologies without needing to be experts in the field. The high degree of automation also helps alleviate the shortage of skilled professionals.
Practical applications in automotive and medical technology
The developed toolchain will significantly accelerate fault detection in safety-critical systems. Automated test case generation and simulation-based robustness testing help to shorten the time-to-market and to optimize the engineering processes. The applied methods are being tested through real-world case studies in the automotive and medical technology sectors.
In the automotive case study, test cases for automated lane-keeping systems based on the UNECE R157 standard are generated from the open-source models from the fortiss Mobility Lab. In the medical technology case study, the project focuses on safety-critical software. The project results are not limited to these sectors—they are also applicable to industries such as aerospace or rail transport. The participating SMEs are using the results to drive innovation across multiple sectors.
The PlaTFoRm project is funded under the Central Innovation Programme for SMEs (ZIM) by the German Federal Ministry for Economic Affairs and Climate Action (BMWK) as well as by Innovate UK as part of joint research and development projects between Germany and the United Kingdom.
