At any particular moment, the energy security of an energy system is at risk from events, both external and internal, that can affect its operation. By analyzing these risks, the state of the system's energy security can be determined. If the method is generic, it can be applied to any energy system and the entities that support its operation. Despite the potential benefits of such a method, a review of the literature shows that existing methods of analysis focus on, for example, limited parts of the system or specific types of energy. To address this shortcoming, this paper presents a method for analyzing the risks to the energy security of any entity in an energy system. The method, derived from work at the National Institute for Statistics and Technology (NIST), determines the risks to an entity using the well-known properties of events (rate of-occurrence and expected stress) and entities (flows, time-to-recover, and stress-tolerance). The paper demonstrates how the method can be applied using both qualitative and quantitative data to measure, analyze, and potentially improve a system's energy security. Several examples are included. (C) 2016 Elsevier Ltd. All rights reserved.