As the investments in IT are still growing and organizations are more dependent on IT than ever before practitioners as well as researchers are still lacking theories or models that help and explain if and when IT has to be adapted, partly exchanged or entirely implemented. In this paper we claim that one major reason for IS change lies in the interaction of human agents while using IT to solve tasks. Human agents cooperate within and simultaneously build a social network that is partly selforganizing, dynamic and uncontrollable from the outside. This dynamic can cause unintended pressure on the use and the usability of IT and therefore may force organizations to change the IS. This article discusses the Structurational Model of IT and concepts of the Social Network Analysis and draws several implications of examining the impact of social interaction on IS change.