Lidé na fakultě
Max Chopart, MSc.

2027, Reliability Engineering and System Safety, 277, ISSN 1879-0836

The complexity of aviation systems necessitates a shift from document-centric methods toward systemic, model-based approaches. While System-Theoretic Process Analysis (STPA) excels at identifying systemic hazards, its qualitative outputs are difficult to verify through simulation. Consequently, practitioners supplement STPA with Model-Based Safety Analysis (MBSA) for executable verification. However, linking these methodologies requires manual translation, a process that is resource-intensive, prone to translation errors, and breaks the “digital thread” essential for traceability. To address this gap, this paper presents a feasibility study assessing whether an ontology-based framework can enable the automated translation of STPA scenarios into executable MBSA conditions. Analysts map scenarios to a generated vocabulary via semantic annotation. A pipeline then synthesizes logic for AltaRica Data-Flow models. The feasibility of the proposed approach is evaluated on the electrical system of a Cessna C510 aircraft. Processing 180 scenarios, the pipeline filtered 101 out-of-scope cases and generated 79 MBSA observers without manual translation. The workflow achieved a 100% Traceability Completeness Ratio, identified redundant scenarios to mitigate state explosion, and reduced engineering time by a 83.1% compared to a manual baseline. These preliminary results demonstrate viability in an industrially representative case, while exposing inherent limits of executable verification, where sociotechnical causes are not simulable and only their cyber–physical effects are.

Článek v odborném recenzovaném periodiku

2026, Transportation Research Procedia, Amsterdam, Elsevier B.V.), p. 263-271), ISSN 2352-1465

As aerospace systems grow in complexity, traditional safety analysis methods are proving insufficient, leading to the adoption of systemic approaches like System-Theoretic Process Analysis (STPA). However, its practical application is often diminished by its cognitively demanding nature, with a significant portion of published analyses being incomplete and lacking independent validation. While prior reviews have mapped STPA’s applications, a dedicated analysis of its integration and automation within the aerospace safety engineering lifecycle has been absent. This paper fills that gap, presenting a systematic literature review of 126 studies to assess the state of the art. This analysis reveals a clear bifurcation in the literature: model-based approaches are well positioned to integrate STPA into the entire engineering workflow, using its outputs to inform subsequent design and verification stages. In contrast, non-model-based applications tend to treat STPA as an isolated, standalone analysis, limiting its impact. Despite the strong trend towards Model-Based Systems Engineering (MBSE), our review identifies several critical research gaps that persist. There is a widespread absence of substantive validation for analytical outputs, limited attention given to methods for filtering and managing the “scenario overload” problem, and a preference for MBSE over the more specialized Model-Based Safety Analysis (MBSA) frameworks. These findings suggest that while the automation of STPA is advancing, its full potential will only be unlocked by addressing these challenges of integration, validation, and scalability.

Stať ve sborníku z prestižní konf. (Scopus)

2025, Procedia Computer Science, Amsterdam, Elsevier B.V.), p. 2448-2457), ISSN 1877-0509

The U-space implementation within airspace management has led to the emergence of research activities focused on information exchange between U-space stakeholders. U-space requires information exchange among various entities, including the Air Navigation Service Provider, U-space Service Provider, Common Information Service Provider, Unmanned Aircraft Systems, and remote pilots. This information must be secured. European Part-IS addresses information security risks by establishing processes to safeguard information used, transmitted, or received during U-Space operations. This paper investigates whether the System-Theoretic Process Analysis for Security (STPA-Sec) can ensure compliance with EASA Part-IS information security risk assessment requirements. By applying the analysis to the CISp operation concept and comparing the outcomes with Part-IS requirements, the results indicate that while STPA-Sec effectively identifies potential security vulnerabilities and hazards, it does not provide specific mitigation recommendations. Therefore, while STPA-Sec can inform the development of security strategies, additional steps are needed to fully comply with EASA Part-IS requirements.

Stať ve sborníku z prestižní konf. (Scopus)

2025, 35th European Safety and Reliability Conference and the 33rd Society for Risk Analysis Europe Conference, Singapore, Research Publishing Services), p. 1191-1198), ISBN 978-981-94-3281-3

This work aims to improve safety assessments in complex systems by presenting an ontology-driven approach to integrating Model-Based Safety Analysis (MBSA) and System-Theoretic Process Analysis (STPA). The ontology serves as an interface with two main goals: (1) to filter STPA scenarios and identify failure-based cases for MBSA, and (2) to automatically translate the filtered scenarios into MBSA-compatible feared events (i.e., "observers"). By bridging STPA's hazard identification methodology with MBSA's failure-based analysis, this approach offers a more efficient and comprehensive framework for system safety and reliability assessment. Even though the improvement of overall safety is a goal shared by both STPA and MBSA, their approach to doing so is different. STPA provides a broad hazard identification framework capturing a range of scenario types, including non-failure cases driven by systemic, human, and organizational factors. In contrast, MBSA focuses on the study of failure propagations. These methodologies are thus complementary and can offer a more complete picture when used together; however, achieving such integration requires a systematic approach to filter and map relevant information between them. To categorize STPA scenarios and eliminate those unsuitable for MBSA, the created ontology serves as a common framework by ensuring that only scenarios appropriate for MBSA's failure-based approach are transferred. The ontology lessens the need for human intervention improving accuracy and enabling more thorough fault propagation analyses by automatically converting compatible STPA scenarios into MBSA's format. Early findings show that this strategy improves the effectiveness of the safety assessment process while also streamlining the integration of STPA and MBSA. The ontology-driven interface enables the utilization of both methodologies' strengths through a methodical and structured mapping, providing a unified framework that can be tailored to the intricacies of contemporary safety-critical systems.

Stať ve sborníku z mezinár. konf.

2024, New Trends in Civil Aviation: Proceedings of the 24th International Conference on New Trends in Civil Aviation 2024, Praha, České vysoké učení technické v Praze), p. 261-267), ISBN 978-80-01-07181-6, ISSN 2694-7854

This paper explores the integration of System-Theoretic Process Analysis (STPA) in Model-Based Safety Analysis (MBSA) for aircraft safety assessment, using the electrical system of the Cessna C510 Citation Mustang as a case study. It highlights how each method's unique strength, i.e., STPA’s focus on system interactions and MBSA’s detailed system modeling, complement each other to provide a more comprehensive safety analysis. The integration demonstrates improved hazard identification and safety assessment, suggesting this combined approach could significantly enhance the safety process in aircraft systems. The findings support the efficacy of merging STPA and MBSA, aligning with modern safety engineering guidelines and opening pathways for future research in complex system safety analysis.

Stať ve sborníku z prestižní konf.

2023, 2023 New Trends in Aviation Development (NTAD), Praha, IEEE Czechoslovakia Section), p. 77-82), ISBN 979-8-3503-7042-3, ISSN 2836-2756

Flight procedures are one of the main pillars for the safe performance of a flight. However, sometimes flight procedures must be modified. The need to modify them may arise from operational experience or a safety study. One of the methods that can be used to perform a safety study for the purpose is System-Theoretic Process Analysis (STPA). The goal of this paper was to perform a safety assessment of the Cessna 172 flight procedures based on a proactive systems approach to safety, using STPA. The goal was to identify potential safety issues related to selected flight procedures and to propose corrective measures or safety recommendations that could be used in practice. The results show how to work with STPA in the context of flight procedures and what measures or recommendations emerged from the analysis for the Cessna 172 flight procedures. The analysis confirmed the possibility of using system safety approach in general aviation to assess flight procedures and usefulness of its results.

Stať ve sborníku z prestižní konf. (Scopus)

2022, Transportation Research Procedia, Amsterdam, Elsevier B.V.), p. 230-237), ISSN 2352-1457

To conduct reliability studies, Fault-Tree Analysis (FTA) and Failure Mode and Effect Analysis (FMEA) are among the most used methods. However, with the emergence of software and complex modern systems, such analyses are not sufficient anymore. Therefore, System-Theoretic Process Analysis (STPA) was created to solve such problems and conduct safety analyses but was never used for a reliability analysis. This paper presents a reliability study of the Wheel Braking System (WBS) of the Cessna Citation Mustang using STPA, and a comparison study using FMEA. Outputs of both methodologies were compared and showed that STPA produces better results.

Stať ve sborníku z prestižní konf. (Scopus)