Estimation of human error probabilities in life-saving appliance services: an ER-SLIM based analysis of rescue boat annual inspections

This study presents an enhanced approach for quantifying human error probability (HEP) in rescue boat annual inspections by integrating the Success Likelihood Index Method (SLIM) with Evidential Reasoning (ER). While SLIM enables structured HEP assessment, its conventional use is limited by subjectivity in expert judgment. ER addresses this by systematically aggregating diverse expert opinions. The methodology was applied to all inspection phases defined in MSC 402(96), identifying high-risk tasks with elevated HEP values, notably operating the davit under load (1.39E-01), inspecting the governor and gearbox (1.20E-01), and testing the release mechanism during water entry (1.18E-01). These findings offer a data-driven foundation for improving inspection reliability, developing targeted safety protocols, and enhancing service engineer training. The proposed framework contributes to evidence-based safety improvements in maritime equipment maintenance and holds relevance for broader inspection domains where human factors are critical.