## 5 Conclusions  
Due to the particularity of the geographical environment and the attributes of relevant maritime survey reports in the waters of Taiwan, we adopted an integrated research method to conduct a risk assessment and analysis of ship collision events. The research found that this method of analysis can also achieve the effect of risk assessment and management through the experience and knowledge of local experts in other sea areas with special geographical and hydrological characteristics. In conclusion, we summarized 29 risk factors through a literature review, including 15 human-made factors, 9 ship-relevant factors, and 5 environment-related factors. We extracted the representative risk factors with high relevance, high influence level, and high incidence rate by the selection of criteria specified by the decision-making group and performed calculations using RST and ROSE2. Among all, four human-made factors, one ship-relevant factor, and two environment-related factors were selected. The human-made factors of ship collisions, including carelessness, improper operation of equipment or machinery, and unfamiliarity with local navigation regulations and ship characteristics, were the most causal and influential risk factors. In addition, the equipment and management of the ship were also factors contributing to ship collisions. For example, the steering gear of a ship is one of the most important pieces of equipment to control the ship, and the malfunction of the steering gear would affect the operational ability and increase the probability of a ship collision. For environment-related factors, poor weather and sea conditions not only affected the visibility when the traffic density was high but also greatly influenced crew members' mental conditions and ability to make judgments. To cope with a great number of large-scale ships and the explosive growth in shipping, the demand for crew members has relatively increased. Since human negligence is the main reason for ship collision incidents, the establishment of a retention and elimination policy might be a company's management strategy to create and maintain a good awareness of ship safety. In addition, pre-employment education and training specified for the main trafficking routes of the company, including the basic troubleshooting of machinery and equipment, navigation-related specifications, and ship characteristics, should be implemented. Moreover, we should establish a standard operating procedure for repair and maintenance on shipboard. In addition to executing annual repairs in accordance with the relevant inspection regulations of the Shipping Law, the annual repair and maintenance expenses should also be increased along with the aging of the ship. The critical equipment related to navigation safety should be replaced with new ones to reduce the incidence of ship collisions and other consequences, such as marine environmental pollution. This ensures the safety of personnel and the navigation environment. The results show that through such a research method, we can manage and control multiple risk factors at the same time and through a clear and visualized risk analysis diagram, including reasons, prevention, and mitigations of the incidents, so that we can clearly determine the cause of a ship collision and its related preventive measures intuitively. Conceptualization, Y-C-C., M-T.L. and S-H.H. ; methodology, Y-C.C. and M-T.L. ; software, S-H.H. ; validation, Y-C.C. and M-T.L. ; formal analysis, S-H.H. ; investigation, S-H.H. ; resources, Y-C.C. ; data curation, S-H.H. ; writing--original draft preparation, S-H.H. ; writing--review and editing, Y-C.C. and M-T.L. ; visualization, S-H.H. ; supervision, Y-C.C. and M-T.L. ; project administration, Y-C.C. All authors have read and agreed to the published version of the manuscript. This research received no external funding. Not applicable. The data presented in this study are available on request from the first author. The authors are thankful to the experts involved in the study.