A risk assessment of an autonomous navigation system for a maritime autonomous surface ship

The maritime industry is undergoing a of Marine Autonomous Surface Ships (MASS). It is expected that, with the introduction of maritime autonomous technologies the safety performance of maritime operations increases. Nevertheless, the safety of the MASS must be properly planned and then demonstrated. This applies to the functionality of any Autonomous Navigation System (ANS). The nature of the risks related to an ANS might differ significantly from the traditional maritime risks. Therefore, mitigating these risks before applying an ANS to real-world operations is critical. This study analyses and assesses the risks of a currently developed ANS by integrating the System-Theoretic Process Analysis (STPA) and Bayesian Networks (BN) into a two-stage process. The study results provide a holistic view of the underlying risks in the ANS and the functionality of formulated Risk Control Options. The risk levels of loss events are computed within a model to represent the effects that each loss may have on the safety of the ship’s navigation and the company’s overall reputation. The assessed Risk Control Options provide information to system developers to elaborate an ANS that is safe by design.