Energy-efficiency improvements resulting from the use of information technology for reheating furnaces in an integrated steel plant are evaluated. An energy-use model based on data recorded for 12 years is identified by using regression techniques. Links between efficiency changes and process modifications taken in the past are searched by comparing measured and model data. The model is also used to evaluate the impact on energy efficiency resulting from the installation of new measurement and control equipment. The results show that information technology has contributed to increased energy efficiency.