A common criticism of the sustainability field is that definitions are vague and that the vast amount of different tools, methods and concepts leads to confusion. In response to this challenge, for the past 25 years a group of scientists has explored the possibility to develop an overarching and unifying framework that would allow for a structured overview of other concepts, methods and tools and therefore allow for concrete, strategic planning for sustainability. Over this 25-year period the Framework for Strategic Sustainable Development (FSSD) has been tested in learning loops between scientists and practitioners and has continuously been developed. The aim of this research is to contribute specifically to the social sustainability definition of this framework, which has been found lacking both in theory and practice.

The research first establishes exactly in which ways the social dimension is underdeveloped, both from a theoretical and from a practitioner’s perspective. In addition, the research explores the general field of social sustainability in order to understand the larger field, but also to gather inspiration and understand similar approaches. This exploration leads to the conclusion that also the larger field of social sustainability is also under-developed and underscores the importance of this research.

Based on this conclusion, a new approach to social sustainability within the FSSD is created based on a systems approach to the social system. Various aspects of the social system are identified to be essential for sustainability, namely trust, common meaning, diversity, capacity for learning and capacity for self-organization. Then, overriding mechanisms by which these aspects of the social system can be degraded are identified. Based on the understanding of the essential aspects of the social system and the identified overriding mechanisms of degradation of these, a hypothesis for a definition of social sustainability by basic principles is presented. The proposed principles are, that in a socially sustainable society, people are not subject to structural obstacles to: (1) health, (2) influence, (3) competence, (4) impartiality and (5) meaning-making. These aim to function as exclusion criteria for re-design for social sustainability. The research then presents two evaluations of this new approach, one based on workshops and interviews with FSSD practitioners and one via an FSSD-analysis of ISO 26000. Both evaluations support this new approach as useful and workable, and also contribute to suggestions for further improvement. 

Overall, the research contributes with a hypothesis for a definition of social sustainability, which is general enough to be applied irrespective of spatial and temporal constraints, but concrete enough to guide decision-making and monitoring. This is a contribution to systems science in the sustainability field, and it is a step towards creating an enhanced support for strategic planning and innovation for sustainability.