D-S evidence based FMECA approach to assess potential risks in ballast water system (BWS) on-board tanker ship

Ballast water is essential for cargo ships since it stabilizes vessels at sea. Most ships are equipped with a ballast water system (BWS) to maintain safe operating conditions. This paper attempts to perform a risk assessment for the BWS on-board tanker ship as it poses a major threat to the operational safety of the ship, marine environment, and cargo. To achieve this purpose, the paper utilizes a robust methodology integrating D-S evidence (Dempster-Shafer) theory and FMECA (Failure mode effects and criticality analysis). In the methodology, while the D-S evidence theory introduces a proper mathematical framework to handle epistemic uncertainty in the assessment of risk parameters and to prioritize failure modes as intended, the FMECA is capable of evaluating system potential failures and their causes. Hence, the risk priority number (RPN) can be calculated to assess potential hazards and their consequences in BWS on-board ships. Besides its theoretical insight, the paper contributes to marine safety inspectors, safety researchers, and HSEQ (Health, Safety, Environment, and Quality) managers to identify potential hazards, effects, and consequences in case of BWS failures on-board tanker ships.