Accident-based human reliability assessment of ship mooring Operations: An Entropy-SLIM framework

Mooring operations are among the most hazardous activities in maritime transportation and continue to cause injuries and fatalities. Although accident investigation reports provide information on contributing factors, their use in human reliability assessment (HRA) remains limited. This study proposes an accident-informed framework to estimate human error probability (HEP) in ship mooring operations by integrating the Success Likelihood Index Method (SLIM) with the Entropy Weight Method (EWM). Thirty-five accident investigation reports were analysed to identify performance shaping factors (PSFs) associated with human error. The PSFs were transformed into an occurrence matrix, weighted using entropy analysis, and incorporated into SLIM to estimate HEP values for tasks. The execution-related mechanism (T6.1) yielded a slightly higher accident-informed HEP than the perception-related mechanism (T6.3) (6.42 × 10 −4 vs. 5.67 × 10 −4 ) and a higher frequency-based risk contribution index (0.0122 vs. 0.00738). Within Task T6, two main failure mechanisms were identified: execution-related failures associated with line handling and perception-related failures associated with hazard recognition. T6.1 represented the higher-priority mechanism within the analysed accident sample because it combined a slightly higher HEP with higher accident occurrence frequency. The findings support practical priorities for mooring safety, including coordinated command and execution, safe crew positioning, proper line handling, continuous situational awareness, and scenario-based onboard drills.