Mastering the complexity: An enhanced cellular automata-based framework for simulating resilience of hospital Power-Water-Firefighting-Space nexus system

Abstract

Modeling the resilience of hospital Power-Water-Firefighting-Space (PWFS) nexus systems is a complex, dynamic, and nonlinear challenge characterized by high uncertainty. Existing methods, mainly agent-based and network-based models, face difficulties in balancing detailed component-level behaviors with broader system-level interdependencies and neglect the impact of external disruptions, such as surges in service demand during the COVID-19 pandemic, on hospital PWFS system resilience. To address this, the study proposes an enhanced cellular automata (CA)-based framework for simulating hospital PWFS system resilience. The PWFS system is modeled as a seven-tuple CA, incorporating cell structure, state, space, neighborhood, transition rules, and time, facilitating the integration of micro-level component behavior with macro-level interdependencies. A set of resilience metrics, including robustness, rapidity, performance loss, and an integrated resilience index, are introduced, based on the system performance curve, which includes normality, connectivity, resource transfer efficiency, and space functionality. The model enables scalable, polynomial-time simulations of cascading failures, resource redistribution, and spatial–temporal recovery across interconnected PWFS subsystems. A real-world outpatient building case study demonstrates the applicability and validity of the enhanced CA model. The findings emphasize the importance of modeling intra-system interdependencies and provide actionable insights for infrastructure design and emergency preparedness. Overall, the enhanced CA framework offers a systematic, scalable, and computationally efficient approach to resilience assessment, bridging theoretical modeling with practical infrastructure planning.