A review of sustainability models as system of systemsA review of sustainability models as system of systems Peer-Reviewed Journal Publication Δημοσίευση σε Περιοδικό με Κριτές 2015-10-052010enMany people believe that our society is at the crossroads today because of societal and environmental problems of scales ranging from the local to the global. Such problems as global warming, species extinction, overpopulation, poverty, drought, to name but a few, raise questions about the degree of sustainability of our society. To answer sustainability questions, one has to know the meaning of the concept and possess mechanisms to measure it. In this paper, we examine a number of approaches in the literature that do just that. Our focus is on analytical quantitative approaches. Since no universally accepted definition and measuring techniques exist, different approaches lead to different assessments. Despite such shortcomings, rough ideas and estimates about the sustainability of countries or regions can be obtained. One common characteristic of the models herein is their hierarchical nature that provides sustainability assessments for countries in a holistic way. Such models fall in the category of system of systems. Some of these models can be used to assess corporate sustainability.http://creativecommons.org/licenses/by/4.0/systems jou1415 - 25 Yannis Phillis Φιλλης Ιωαννης V. S. Kouikoglou V. Manousiouthakis IEEE Biotic succession Succession, Ecological ecological succession biotic succession succession ecological