- The developmental milestones of Sustainability are consistent with the post-normal versus traditional science, where transdisciplinary and policy/action research are among the important approaches to be added to traditional analysis. This shift 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. In addition, the modeling and simulation methodologies required for Sustainability research need to not only be technically rigorous and robust, but also encompass the human, market, and environmental factors as well as their interactions. Therefore, System Dynamics (SD) is one of the simulation tools that has been used to develop various Sustainability Assessment models, where the complex structure of an organization’s unique Sustainability problem can be constructed, and management can benefit from the simulation results of their Sustainability indicators. Furthermore, research has pursued various interpretations and methodologies for Sustainability Assessment, partly due to attempts to overcome the vagueness of Sustainability concepts. This vagueness has also subjected Sustainability Assessment methods to indicator selection bias and organizations being left with a plethora of indicators and methodologies to analyze, interpret, and inform decision making. Thus, to tackle the multifaceted issue of Sustainability, this research aims to develop a systemic Sustainability Assessment methodology by employing the transdisciplinary approach. First, Classical Principal Component Analysis/Factor Analysis (CPCA/FA), aided by Sparse Principal Component Analysis (SPCA) for high dimensional data, was used to generate a set of core Sustainability indicators. Next, building upon an established connection between Sustainability and viability, i.e., the Viable System Model offers a framework to map the self-adapting mechanisms that allow a system to cope with its internal and external Sustainability challenges, a Sustainability Assessment framework that integrates both the Sustainability Indicators (SI) and Viable System Model (VSM) methodologies is developed, where the SI methodology employs core indicators developed in the previous step. Based on the complimentary features of VSM and System Dynamics (SD), the integration of the two methodologies results in a dynamic model of the previously developed Sustainability Assessment framework. The complete SA methodology employs the use of management approach indicators based on the principles and axioms from the VSM, and the use of performance (P), productivity (PR), and latency (L) values to track true improvement. Data collected on the system of interest – the organization used as a case study - and information on applicable market trend is fed into the SD model to predict outcomes of three popular Sustainability indicators so that recommendations can be provided to management. The study illustrates a new methodology for developing a measuring and assessment tool for Sustainability practitioners, as well as answering the call for moving away from the simplistic trade-off approaches towards an integrated SA with modeling and simulation capacities.