In recent days, the use of the fuzzy set theory to deal with social complexity has become more attractive as a research area to academics who wish to contribute to sustainable development. The socio-ecological systems are one of the well-known sub-disciplines of social science which is very critical issue to maintain sustainability and this concept basically concerns with the human-environment interactions. These systems involve various stakeholders with different levels of knowledge and experience from diverse social platforms. The basic characteristic of these systems is identified as having high level of uncertainty and incomplete information. The main purpose of this chapter is to demonstrate how to incorporate fuzzy sets theory into social sciences. In this chapter, an illustrative example which consists of a wide variety of social actors is used to evaluate sustainable management options utilizing the extended technique for order preference by similarity to ideal solution (TOPSIS) method for interval valued intuitionistic fuzzy multi-criteria group decision making.