In recent years, critical infrastructures have become increasingly susceptible to disturbances of various kinds, which could affect the functionality of the system, temporarily or permanently. These disruptions can seriously affect the health and safety of citizens and their economic well-being. Many studies on risk management (including planning and forecasting) have been carried out in order to deal with these impacts. However, sometimes they must face major disturbances, and this has led to the creation of the resilience concept, as a way designed to identify risks, and implement the actions necessary to restore the system to a determined and acceptable level after degradation, with tolerable cost. The aim of this paper is to present the interactions between the different components of resilience. In the first part, we present a state of the art in terms of the different approaches to the components of resilience that can be found in the available literature. The second part of the paper is devoted to the study of the relationship between the components of resilience presented in the R4 approach. This study opens new perspectives for the construction of a model for analyzing the resiliency of urban systems in times of crisis.