The development of engineering technology has improved the performance of the system, but as the components are diversified and the system is becoming larger, various hazards have come into existence. These hazards must be prevented in the system desi...
The development of engineering technology has improved the performance of the system, but as the components are diversified and the system is becoming larger, various hazards have come into existence. These hazards must be prevented in the system design process because they cause accidents in combination with the hazardous situations during the operation after production. Therefore, in the field of defense and civilian industries, safety standards were issued that identifies and evaluates the hazards embedded in the system from the conceptual design phase of the system and provides guidance to integrate the safety measure to the design. However, there is a difficulty in integrating the hazard analysis process presented in the safety standards with the existing system design process. In order to improve this, researches using models instead of documents were conducted when analyzing the hazard in the conceptual design stage. If hazards for system design is identified, design the cause and effect of the hazards as a failure model. In addition, by modeling the safety measure to cope with this effect, it has been shown that it is easy to integrate system design and hazard analysis activities. However, most studies on model-based safety analysis have applied UML or AltaRica-based modeling and verification techniques instead of SysML-based M&S when designing and verifying failure models and safety measures. In addition, SysML was used only in the design of the meta-model and the physical architecture even in the case of research using some SysML. The purpose of the model-based safety analysis is to integrate the system design and hazard analysis activities. Therefore, the failure model and the safety measure also need to be systematically designed and verified through SysML.
This paper proposes a SysML-based design method of safety measure considering reusability in order to systematically integrate hazard analysis and system design activities in the concept design process of safety-critical system. Also, SysML-based design and verification method to integrate safety measure and system architecture is proposed. First of all, the functional architecture of the system of interest is designed by using SysML and the hazards for important functions are analyzed. When the cause and effect of the hazards inherent in the functional architecture are identified and evaluated, the result is designed as a failure model through SysML. The designed failure models are used to identify and design safety measures for hazards. Finally, integrate the designed safety measures into the existing functional architecture and verify that the safety function is operating normally when the fault occurs and verifies that it meets the safety objectives.
The process and method presented in this paper have been verified by applying it to a case study of an automotive brake system. Through the design of safety-critical system using SysML-based M&S methods, it is possible to integrate the system design and hazard analysis activities that were previously separated in the concept design stage, and confirm the concurrence of the initially set functions and safety objectives. It is expected that this paper will be used in the research and development process to systematically assure safety at the early stage of development of safety-critical system in the future.