Reports on the progress of sustainability research have increased significantly during the past decades. The developmental milestones of sustainability are consistent with the post-normal versus traditional science, where trans-disciplinary and policy/action research are among the important criteria to be added to traditional analysis approach. This requires a new perspective to look at the problem at hand: we are no longer considering a group of users with common and self-interested goals when defining the scope of sustainability studies. This in turn requires sustainability indicators that can capture largely diverse but relevant measurements to completely represent the different perspectives that must be fulfilled, and methodologies that focus on heuristics, systemic stability, control, and feedback, versus traditional optimization for mechanistic problems. The present study attempts to build upon current established connection between sustainability and viability, specifically how the Viable System Model offers a framework for organizational systems to consistently perform self-adapting mechanisms to cope with internal and external sustainability challenges, and how these capabilities can help organizations achieve their sustainability development goals. A sustainability assessment model that integrates both the sustainability indicators approach and Viable System Model has also been developed and presented here.