A system-theoretic approach to safety and security co-analysis of autonomous ships

The autonomous ship carrying valuable cargoes and passengers in a more effective and cost-saving manner will soon be state of the art technology, which most likely shall be introduced into the public horizon as the remote control mode within the foreseeable future. The highly connected intelligent systems though come at the cost of the increased system vulnerability to cyber-attacks. To smooth this innovative system can be released into actual context of operation, a novel STPA-based methodology is proposed that synthesizes safety and security, namely STPA-SynSS. In the novel method, a comprehensive process to identifying hazards and revealing causal factors is provided, hazard elimination/mitigation strategies are implemented into system design via system safety and security requirements, so that hazards can be continually tracked and closed-loop managed. The insight regards the operations of the method was demonstrated in a remotely-controlled ship with seafarers onboard, the analysis process focused on encountering ship-ship collision accidents and related security incidents. Results indicate that generated inadvertent/intentional causal factors and developed elimination/mitigation strategies can assist the processes of design and operational planning of the autonomous ships and its shore control centre. Further, the proposed method of this paper also has general relevance for other intelligent systems.

Automated summary

This paper proposes a novel STPA-SynSS methodology that combines safety and security to help autonomous ship systems better identify and eliminate/mitigate potential hazards, as well as manage these hazards in a closed-loop manner. The empirical findings demonstrate that this method can be effectively applied to design and operational planning, and also has general relevance for other intelligent systems.