Structure model-based hazard identification method for autonomous ships

There is great interest in the practical use of autonomous ships. Although it is important to identify and address serious hazards at the initial design stage when constructing complicated large-scale systems, it is difficult to capture the entire structure of such a system. To address this issue, in this study, we propose the structure model–based hazard identification (SMB-HAZID) method, which is suitable for performing hazard identification of autonomous ships. The primary feature of this method is performing hazard identification using structure and task (ST) diagrams, a checklist, and keywords. The method includes a modeling method that can describe the overall structure of the system together with each component's tasks, information necessary for task execution, and interactions among the components in an ST diagram. In addition, this paper presents an example of using this method to perform hazard identification of a hypothetical autonomous ship at the early design stage. Through this trial application, we confirmed that SMB-HAZID is suitable for analyzing hazards within an autonomous ship. In our future research, we will improve the proposed method by developing and incorporating a technique for quantifying or semi-quantifying risks corresponding to the identified hazards.