Abstract:  In this article, a methodology for energy security assessment in terms of energy system resilience to disruptions is presented. The methodology serves as an integrated framework towards the evaluation of energy security, which directly refers to energy system resilience. The proposed model expands the conventional energy system modelling tools with the ability to model the energy system in the environment of stochastic disruptions. Furthermore, the methodology provides an energy security metric, whose main goal is to quantitatively estimate energy security for future development scenarios or pathways of the energy system in terms of its resilience. The methodology is based on the analysis of emerging threats, disruptions and associated consequences to energy systems combined with the energy system modelling tool OSeMOSYS. Furthermore, the model with its characteristics and modelling algorithm are described, the main strengths and limitations are indicated, and potential future developments and applications of the methodology are discussed. An illustrative case study for Lithuanian energy system, including fuel supply, electricity and district heating, is carried out to demonstrate the applicability and capabilities of the methodology. Three scenarios constructed according to different targets of renewable energy, which are being considered in the project of new National Energy Independence Strategy of Lithuania, demonstrate the potential impact of renewables development on energy security. Full text available here.