Leveraging Complexity Science for Security in Cyber-Crisis: The Stress-Induced Self-Organised Resilience (SISOR) Model

Modern systems-of-systems, such as national infrastructure networks, defence information environments, and financial platforms, must continue to operate even when components fail or are compromised by cyber-attacks. Traditional approaches to resilience focus on identifying and reinforcing critical nodes; however, these methods rely on complete network visibility, incur significant analytical overhead, and are vulnerable to structural changes. This paper introduces Stress-Induced Self-Organised Resilience (SISOR), a proactive approach to building resilience that leverages the natural adaptive behaviour of complex systems. SISOR works by intentionally applying minor, rolling disruptions across nodes in a system, prompting the formation of alternative pathways and service redundancies through self-organisation and feedback loops. Rather than preventing stress, SISOR utilises stress as a tool for resilience development. The approach is visibility-agnostic, computationally lightweight, and scales naturally with the system size. We formalise SISOR through a model that relates the optimal stress frequency to mission assurance priorities and the likelihood of a cyber-crisis. The result is a resilience strategy that strengthens systems before a disruption occurs, reducing the reliance on emergency adaptation during crises and improving survivability in high-consequence operational environments.