Demonstrating a Model-Based Systems Engineering Approach for the Approval of Maritime Autonomous Surface Ships Operation: The Autonomous Mooring System Use Case

The approval of Maritime Autonomous Surface Ships (MASS) requires a structured and transparent approach to demonstrate that the safety of autonomous operations is at least equivalent to conventional vessels. To achieve this, a Model-Based Systems Engineering (MBSE) framework has been established, combining system modelling, safety analysis, and verification activities within a unified process. This paper presents a use case demonstration of the MBSE approach through an Autonomous Mooring System (AMS) operation, aiming to provide a clear and practical understanding of how MBSE can be utilised in the approval process of autonomous ships. The AMS operation is performed by an autonomous vessel equipped with robotic mooring arms mounted along its sides, which automatically connect the mooring lines to port-side bollards. After receiving port clearance from the Remote Operations Centre (ROC), the Digital Orchestrator (DO), as the onboard controller, instructs the AMS to initiate the mooring sequence using camera-based perception for bollard detection. The AMS operates autonomously or in a highly automated way, with decision-making capabilities to continue or abort based on input from the autonomous navigation and situational awareness systems. Through this use case, the paper illustrates how the MBSE steps, requirements definition, concept of operations (CONOPS) development, system formalisation using modelling language (such as, unified modelling language, UML, system modelling language, SysML), and verification and validation with safety analysis (System Theoretic Process Analysis, STPA) and test cases can be systematically applied to ensure sufficient safety. The demonstration aims to familiarize stakeholders with the MBSE methodology, emphasising its potential to enhance traceability, transparency, and regulatory confidence in the approval of autonomous ship operations.

Keywords: Autonomous Mooring System (AMS), Model-Based Systems Engineering (MBSE), Maritime Autonomous Surface Ships (MASS), UML, Safety analysis, STPA, Safety assurance.