Sustainability is a concept that has arisen from the debate on sustainable development, which became important from the 1970’s onwards. However, for many organizations in the development sector, the United Nations document written in 1987, entitled “Our Common Future”, is probably the most widely quoted definition. According to the report; “Sustainable development is development that meets the needs of the present generations without compromising the ability of future generations to meet their own needs.” This definition marks an important shift away from the idea of sustainability as primarily concern of ecology to one that emphasizes the economic and social processes of development.