For over two decades, implementation has been studied by scholars adopting various perspectives. For example, implementation has been framed as an effective relationship(Churchman and Schainblatt, 1965), as an outcomethat is determined by individual, organizational and situational factors(Lucas, 1975; Schultz et al., 1984; DeSanctis, 1984), and as aprocess of organizational change(Ginzberg, 1978). This process view has been further developed by scholars influenced by the sociotechnical schoolof thought (Bostrom and Heinen, 1977; Markus, 1983; Robey, 1987), and this synthesized approach arguably represents the dominant approach for understanding IS implementation today. Within this perspective, an organization is implicitly conceptualized as a "diamond" consisting of interacting components: people, tasks, technology and structure. Introduction of an IS involves changing the technology component of the organization, which automatically triggers a change in the other components. Implementation essentially refers to anticipating and strategically managing these impacts of the change in technology(Robey, 1987) such that the IS becomes "organizationally valid" (Schultz and Slevin, 1975; Markus and Robey, 1983) as the organization attains a post-implementation steady-state. Scholars usually focus on interactions of different components of the "diamond" and recommend organizational impact management strategies such as job redesign, training or education, and changing the reward systems. While this "interactionist" approach represents considerable progress, it is argued that the underlying "diamond model" fails to reflect the political underpinnings (Keen, 1981; Markus, 1983) and institutional realities such as symbols (Hirschheim and Newman, 1991) and frames (Orlikowski, 1992) sufficiently. This paper attempts to enrich the existing organizational model based on insights from Berger and Luckmann's work in the arena of sociology of knowledge, and through the application of this enriched model, contribute to the stream of sociotechnical literature on IS implementation. The basic thesisof the paper is as follows: Prior conceptualizations of organizations have recognized only "objective realities" which has led to an incomplete understanding of implementation; by including the analysis of "subjective realities" in the organization, a better understanding of political and institutional forces and of resistance arising from them may be gained. The following section develops the model. The next section provides guidelines for managing implementation that are derived from the model. The final section concludes with the limitations of the model and future research directions.