The statistical data on world’s population of the last years seems to suggest a growth of the population size and a trend of people moving to the big cities [1]. As a consequence, the energy and services demand will increase [2],[3], [4] and, to face this problem, future cities must be more and more efficient. For this reason the new concept of smart city, which is supposed to lead to a more and more efficient and energy saver city, is considered very promising. However, it is not easy to provide a single and comprehensive definition of the smart city [5], and several tentative definitions are already available in the literature. To the purposes of this paper, a smart city can be defined as a city able to facilitate and satisfy citizens, companies and organization needs, by an integrated and original use of Information and Communication Technologies (ICT), especially in communication, mobility, environment and energy efficiency fields [6]. In this definition is well underlined the important role of ICT in a smart city. Thanks to hese technologies is possible to improve citizens’ quality of life, decreasing pollutant emissions, reducing energy consumptions and economic costs [7]. A smart city is indeed an environment that pays attention to people’s needs, rational resources management, sustainable development and economic sustainability. A city with more efficient services, and with more environmental sustainable and smart energy usages. To achieve these aims it’s necessary to evaluate private and public measures and technologies effectiveness, in other words evaluate the sustainability of smart solutions. For these reasons a new analysis approach has been developed and proposed with the name of Smartainability [6], [8].

۲٫ Methodology – Smartainability

The aim of the Smartainability approach is to estimate, with qualitative and quantitative information, to what extent smart cities are sustainable thanks to the deployment of smart technologies. In this framework we had the opportunity to test, at least for Europe, the methodology on the “Expo Milano 2015” smart digital city. The universal exposition site “Expo Milano 2015” wanted to be an example of future city districts [9],[10]. Thanks to an ad hoc agreement with Expo 2015 SpA, the exposition district, which represents a particularly advanced model of smart city suitable to develop and validate the methodology, has been chosen as a first case study. Starting from the Expo Milano 2015 case-study the methodology is tested and developed to be extended and repeated in other and more complex contexts, like a city district or a whole city.