1 5 th SASTech 2011, Khavaran Higher-education Institute, Mashhad, Iran. May 12-14. Reflections on Modeling Systems’ Resilience Amin Hosseinian-Far 1 , Hamid Jahankhani 2 , Elias Pimenidis 3 , D. C. Wijeyesekera 4 School of Computing, IT and Engineering University of East London {Amin 1 , Hamid.Jahankhani 2 , E.Pimenidis 3 , Chitral 4 @ uel.ac.uk} Paper Reference Number: 1112-111 Name of the Presenter: Amin Hosseinian-Far Abstract Modeling sustainability of a system is a complex and challenging process. In addition, it might not lead to a factual answer in the end. Modeling systems‟ resilience as opposed to systems‟ sustainability is an approach to check the endurance of a system. There are different systemic approaches to model sustainability and also the resilience. This paper presents the domains where resilience and sustainability can be used interchangeably. Furthermore, a systemic approach to model systems‟ resilience is assessed. Key words: Systems‟ Resilience, Sustainability, Complex Adaptive Systems, Systemic Modeling 1. Introduction Current energy crisis and climate change catastrophe have emerged the use of sustainable systems such as solar systems. Implementation of such projects requires a sustainability analysis in order to ensure the durability and profitability of the projects. Current sustainability assessment models are restricted by the limitations of their boundaries. The emergence of dynamic and complex systems as a modeling method have already yielded favorable results in a variety of applications, such as modeling ants nests, local ecosystems, and large space-based projects where the interaction of the parts bears significant effect on the final outcome. It is suggested that the complex modeling methodology be applied to sustainable models in order to derive a more realistic outcome. In addition it is proposed to have a complex adaptive methodology for the effect consideration of the policies involved. The complex nature of sustainable systems requires a better conceptualization in order to able to model what needs to be modeled. This research tries to look at resilience of complex systems opposed to sustainability of system. It reviews the prospect of this approach through wide-ranging narrative extraction. 2.Sustainability