A novel methodology to quantify the impact of safety barriers on maritime operational risk based on a probabilistic network

This study introduces an innovative probabilistic network designed to integrate workflow, operations, and safety barriers involved in operational risk propagation, based on which a generic risk model is proposed to quantify the impact of safety barriers on operational risk. For this purpose, a structural barrier module is defined to describe the interaction mechanisms between operations and risk. This module encompasses scenarios such as risk mitigation based on barriers, risk escalation facilitated due to barrier performance degradation, and natural risk attenuation. The barrier modules are integrated into the probabilistic network, which incorporates both workflow and risk propagation, thereby providing detailed insights into risk propagation under the impact of barriers and operations. To evaluate the impact of barriers, a quantitative analysis framework is presented based on probability theory, including the network Green's function and path search algorithms. Furthermore, a sensitivity analysis is employed based on Green's function to illustrate the optimization of possible intervention strategies. Finally, the impact and sensitivity of the barriers are combined in a two-dimensional space to classify the barriers, leading to recommendations or countermeasures for safety barrier management. The methodologies proposed in this study shed light on the cooperative mechanisms of barriers for operational risk control.