Following a literature survey which shows the existence of large variations among studies in the construction of energy security indexes, this paper proposes a framework with a composite index and three sub-indexes for evaluating Singapore's energy security. The sub-indexes capture the economic, energy supply chain and environmental dimensions of energy security. A total of 22 indicators, normalised using the banding approach, are aggregated to form the sub-indexes and the composite index referred to as the Singapore Energy Security Index (SESI). These indexes are generated for selected years from 1990 to 2010. The results show that Singapore's energy security has remained fairly stable throughout the period. Further analysis shows that the energy supply chain and environmental sub-indexes have improved, but the improvement was offset by the decline in the economical sub-index. The proposed framework allows quick identification of deficiencies within the Singapore's energy supply chain in the context of energy security by pinpointing its main weaknesses. It is particularly suitable for quantifying energy security of countries that are highly dependent on energy imports to meet their energy requirements. (C) 2015 Elsevier Ltd. All rights reserved.