Let’s try to define the concept of sustainability, better explained by the terms “sustainable development”, accorting to the needs of the economic and productive system and trying not to deny the rights of future generations. The first official definition for sustainable development keeps in mind this logic: in 1987 the Brundtland Commission states:
Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs
During the years, many people tried to figure out the correct methods to measure this concept in real-world: how to measure it? What’s the key factors to keep in control? How can we count the natural and the social capital? These questions are matter of discussion still today.