Non-linear models for understanding complex socio-technical processes have not been fully adopted in the examination of hospitals’ functional performance when managing the effects of disruptive events. In the literature, researchers have focused on the various dimensions of hospital functional performance (HFP) using different methods. However, they have not sufficiently addressed the inherent behaviours of systems that diminish the efficiency and effectiveness of HFP when operating under different protocols. The current paper aims to identify the pathway through which functional variabilities may propagate throughout the system when dealing with medical surge. To achieve this objective, the application of the functional resonance analysis method (FRAM) is integrated with the application of the resilience analysis matrix (RAM) to analyse HFP. The results identify 23 couplings in 153 interactions between 29 functions that have the potential to affect overall HFP. The approach of this research has revealed how managing the variability of certain interactions can enhance the efficiency and effectiveness of HFP in dealing with disruptive events.