Eunbi Kim  Hyuksoo Han

10.5626/JOK.2018.45.7.667

safety critical system hazard analysis process SysML requirement diagram

Today, the accident of safety critical system may result in catastrophic harm to people and environments. Therefore, activities designed to ensure safety, such as identifying the hazard and mitigating risks to prevent those accidents, need to be enforced in system development, especially at the concept phase. PHL and PHA can be hired to identify preliminary hazards and to do Failure Modes and Effects Analysis (FMEA), Fault Tree Analysis (FTA) to assess the causes and impacts of those hazards. For developers and safety experts to work together in the lifecycle, those safety activities need to be integrated into the modelling of system development. The common modelling language, SysML, has been recognized as a solution for this purpose and several types of research on this topic have been published. However, not much effort has been made to apply requirements diagram to acquire the visibility and traceability of safety requirements derived from those hazards identified by analyzing SysML diagrams at concept phase, with related artifacts such as implementation and verification. In this paper, we propose a hazard-identification process in which behavior and structure diagrams of SysML could be systematically analyzed. Then the safety requirements were derived to remove or mitigate the identified hazard. To demonstrate the capability of the proposed process, an example of applying it to an elevator system is presented.