Combined with failure propagation model, the importance evaluation and critical node identification of five functional nodes of combat system are presented

Abstract In response to the problems of strong heterogeneity of nodes, complex functional dependencies, and insufficient depiction of the impact of systematic failures by traditional assessment methods in the combat system network, this paper proposes a method for evaluating node importance and identifying key nodes by combining the failure propagation model and the network flow blockage theory. Firstly, a directed heterogeneous network model including five types of functional nodes (reconnaissance, command and control, attack, performance enhancement support, and essential support) was constructed, and the resource input and output interfaces and functional dependency paths of each type of node were clarified. Secondly, an improved threshold propagation mechanism was introduced to simulate the diffusion effect of node failures, and a comprehensive influence calculation function based on propagation probability, neighbor overlap degree, and topological KHC index was established. Further, by integrating the maximum flow-minimum cut principle, a propagation-efficiency-coupled key node identification algorithm was designed to depict the weakening effect of node failures on network functional traffic. Through simulation experiments under various failure scenarios and network structures, the results show that compared with traditional centrality indicators, this method has significant advantages in accurately identifying nodes with systematic high-performance loss, and the identification results are more operable and task-chain focused, with good topological adaptability and robustness. The research results can provide theoretical basis and algorithm support for vulnerability analysis of combat networks, anti-destruction design of command systems, and path deduction of suppression.