Cyber–physical–social hazard analysis for LNG port terminal system based on interdependent network theory

•The cyber–physical–social interdependency of the LNG terminal system is studied.•The methodology uses network theory to study interdependency.•Four significant indexes are introduced to reveal the most safety critical units.•The study provides practical recommendation to improve safety management. As city critical infrastructures, LNG port terminal system can be considered as an interdependent network, in which dependency focuses on the scenario in which the nodes in one network require support from nodes in another network. The interdependent network concept and analysis theory are introduced to describe the interaction between physical equipment networks (P-Net) of LNG terminal system, cyber networks (C-Net) and human behavior based social networks (H-Net). This paper further presents a method to systematically study the hazards and risk factors of LNG port terminal from the perspective of cyber-physical-social system based on interdependent network theory. Four significant indexes (dependent degree, weighted dependent degree, dependent betweenness centrality of the interdependent nodes and edges) are introduced, which helps to discover the most safety critical nodes and edges representing interdependent relationships in the LNG terminal system. The case study provides understanding of specific issues such as how interdependent network study can offer better help for safety management and accident prevention.