"For many transport modes, energy reduction strategies can be effectively formulated at the level of the vehicle or vessel. New technologies can therefore be introduced to a vehicle and the direct energy savings can be readily quantified. However, such approach is not suitable to be employed for urban rail, where it is not sufficient to consider only the energy performance of vehicles; the energy associated with the infrastructure, as well as the influence of the mode of operation are to be considered too. In other words, urban rail systems are complex environments and their energy consumption is characterised by a wide range of inter-dependent factors. This means that it is often extremely difficult to assess the net benefits of introducing new energy saving technologies. For example, whilst a new technology might yield improvements in certain respects, it might also compromise other aspects of system performance. What is needed, and what has been lacking so far, is a holistic approach for the reduction of energy consumption for urban rail systems embracing vehicles, infrastructure and operation, as is proposed by OSIRIS. The project will start from the definition of Key Performance Indicators and Standard Duty Cycles to measure energy consumption in urban rail systems. Then, rather than focussing only on specific technologies, it will address the issue from the system-level ensuring that progresses on energy reduction are substantial. The effectiveness of solutions and their full potential will be proven by means of simulations and pilot tests. OSIRIS will introduce the entire discovered knowledge into a Decision Support Tool, for strategic decision making of companies (i.e., operators) and governments (i.e., public authorities). OSIRIS is fully aligned with the political ambitions of the Framework Program described in activity 7.2 - SUSTAINABLE SURFACE TRANSPORT of the FP7 4th call, topic “SST.2011.1.1-4: Energy consumption reduction in urban rail systems”."