The case study described in this chapter concerns the introduction of a new computer based integrated Clinical Information System (CIS) into a British National Health Services Trust-the Sunrise Trust. At the time of the study most of the system modules had been developed and were being tested largely for technical aspects. The system was being introduced during a period when the organization was experiencing significant changes. It was an environment where new structures were being created and the existing ones changed. Indeed, the case study was selected primarily because of these factors. The analysis of these structures, formal and informal, provides insight into the management of information systems. Various stakeholders in the Hospital Trust felt that a computer based information system would facilitate the change process. However the analysis and design of the system posed its own problems. The system turned out to be inflexible with respect to the core health care delivery process. It was also nonresponsive to the needs of the key stakeholders. Analysis of the case shows that clearly the formal methods adopted by the system analysts fell short of determining the rapid changes required for care. In particular this was an important issue, since the context of the British National Health Services posed pressures on individual trusts to be cost effective. This resulted in long term patients being moved out into the community. However, this richness in the context was overlooked by the analysts. They developed “logical” models of the system, which ended up in being “tidy pictures of reality” and were prescriptive and utterly inflexible. Structured Systems Analysis and Design Method (SSADM) was used as a modelling tool, which amplified the rational view of decision making and information technology (IT) applications (for more details on SSADM see Downs et al., 1988). The interpretations identified in the case show a clear mis-match between the formal models and perceptions of the system users who inevitably reflect a more informal and pragmatic approach to their own organizational realities. The analysis of the case poses a number of interesting issues. It questions the relationship between the complexity of the social relations and systems design. Furthermore it brings to the fore the paradoxical viewpoints of different stakeholders and the emergent concerns for a system analyst. The chapter also identifies the impact of an “overformalized” information system on the integrity of an organization. In doing so it evaluates the nature and significance of social power structures in systems analysis, design and implementation.