Assessing human reliability in reactive cargo handling for chemical tanker ships

This study assesses human reliability in reactive cargo handling on chemical tankers and proposes a hybrid Dempster-Shafer (DS)-extended Success Likelihood Index Methodology (SLIM) approach to enhance process safety. A hierarchical task analysis decomposes the operation, DS theory aggregates expert data to address subjectivity and uncertainty, and SLIM derives task/subtask HEPs. Human error probabilities are aggregated at the system level to assess overall system reliability. The novelty lies in assessing an under-researched high-risk shipboard operation with a novel hybrid methodology and offering practical risk mitigation strategies. Key findings show task complexity as the most influential PSF, followed by training/experience. Inhibitor quantity calculations, continuous monitoring procedures, and thermal management operations are revealed as the most critical tasks. Consequently, the overall human reliability is calculated as 8.20E-01. The findings provide valuable insights for maritime stakeholders, suggesting targeted interventions in calculation protocols, monitoring systems, heat management strategies, and specialised crew training to enhance process safety in handling reactive cargo onboard chemical tankers.