Description du projet :
Today's technical systems are getting more and more complex associated with the rapid increase of new technologies in a number of industrial domains. These systems have one feature in common: the increasing amount and complexity of software. And they have to be safe against humans and the environment. Ascertaining the safe behavior of technical systems is key. Therefore, a number of safety regulations and standards have emerged just over the last decade. Consequently, there is a significant growth of the scope and the intensity of safety assessments of technical systems required to being compliant with these safety regulations and standards. However, this has also an impact on today’s approach of performing safety assessments which are predominantly carried out “manually”, i.e. today’s commercially available and cross-industry used safety analysis tools, that are no longer up to date to cope with the complexity of technical systems. Regulations in aerospace support to get off the traditional safety analysis way to a Model-Based Safety Analysis (MBSA) in order to minimize analysis errors as early as possible in the development phases of technical systems though the systems are getting constantly more complex. Model-based safety analysis has the benefits of identifying failure scenarios in a repetitive manner prior to the detailed design of technical systems and allows an automated execution of the required safety assessments, hence, further reducing potential “human errors” when analyzing systems safety. Other industries have already started to follow the aerospace approach.
In order to compete with the increasing complexity of technical systems in combination with the faster time-to-market demands guaranteeing the required level of safety, a framework for a requirements-driven optimization of the system concepts in conjunction with a Model-Based Safety Analysis (MBSA) respectively Model-Based Systems Engineering (MBSE) is proposed for this research project. By integrating MBSA into the MBSE based development of the system concepts, an automated procedure was developed respecting the relevant safety regulations/standards.
The automated MBSE-MBSA procedure is available for the industrial partners after being tested for several use cases. This procedure makes the automatic generation of FTA and FMEA from a common qualitative technical system model described with the SysML language. The SysML modeling includes both the description of the nominal system behavior and of the failure system behavior. This way of system modeling ensures a full MBSE-MBSA integration enabling the industrial partners to identify earlier in the preliminary concept phase the critical and in many cases safety-related design aspects. The automated procedure combines the modeling method of the nominal and failure system behavior using SysML and the coupled safety analysis using smartIflow Workbench v0.3.9 with the automatic generation of the safety analysis artifacts.
The tooled-procedure for MBSE-MBSA integration consists of enhanced system modeling structure, using the SysML language, which includes the nominal and failure modes in a single model. The interface between SysML and smartIflow is bridged by a specific Plug-in . Once to export/translate the data in
smartIflow, where the analysis of failure modes is conducted and post-processed. The automated generation of fault tree analysis (FTA) and failure mode and effect analysis (FMEA) is performed by two Plug-ins into smartIflow Workbench.
For simple technical systems analyzed, the automatically generated FTA and FMEA are similar to the manual FTA and FMEA, except additional detected failure modes for automated FTA and FMEA. The automatic creation of the safety artifacts helps to avoid human errors of omission or misunderstanding of the system. For technical systems of industrial partners, the automated procedure has limitations and is not yet sufficiently developed. The model checking algorithm of smartIflow transforms the generic model representation into a transition system. Ideally, the graph contains paths for every possible sequence of input event, so that every possible evolution of the system is covered. Since the complexity can be enormous, suitable solutions to model high-level system, to control the size of the transition system and to compute the potential failure modes require further research and development
Research team within HES-SO:
Partenaires académiques: Pascal Bovet, Haute école d'ingénierie et d'architecture de Fribourg; Roland Scherwey, Haute école d'ingénierie et d'architecture de Fribourg; Rüdiger Lunde, Hochschule Ulm
Partenaires professionnels: Melina Brunet, Johnson Electric Morat; Alexandre Chassot, Meggitt, Villars-sur-Glâne; Juan Manuel Florez, Liebherr Machine Bulle, Bulle; Robert Fritsch, Brusa Eletronik, Sennwald
Durée du projet:
08.11.2018 - 17.02.2020
Montant global du projet: 256'000 CHF