Safety Assurance Techniques for the Development of a Rail Industry Safety Case

This research paper addresses the shortcomings of the Goal Structuring Notation (GSN), which has been deployed in many safety cases, including the railway and other industries such as health care, oil and gas, and aviation.The GSN is a graphical presentation that has been deployed to present the safety argument in the case. However, the GSN does not provide a substantiated safety analysis method in itself. The lack of concreteness in GSN presents several limitations in safety analysis, including self-fulfilling prophecy, false confidence, a focus on process rather than property, and difficulties in identifying omissions.This research paper employed a qualitative research method to investigate the research problem through five major case studies. The findings highlighted that safety assurance activities must be integrated into the system lifecycle, from design through implementation, operation, and maintenance. The main safety assurance tasks are safety risk assessments, which shall be undertaken to identify foreseeable hazards and either eliminate or manage them to a level So Far as Is Reasonably Practicable (SFAIRP). Moreover, during the research, it was also noted that high technology, such as Automatic Train Protection (ATP), undermines the concept of safety causation models, including the Domino and Swiss Cheese models.