This study aims to examine the way routine organisational work processes are transformed through the introduction of a new information system in an emergency department. By conducting a 9-month longitudinal case study in one of the major Australian emergency and trauma centres, we investigate the process of organisational work routine transformation in detail. A structuralist investigation perspective based on Structuration theory and the concept of IT duality is adopted to enable a detailed examination of the dynamic interplay between work routine and IS throughout the transformation process. We propose a three-phased development model which facilitates better understanding of the consequences of IS implementation and management by highlighting different transformational focii at different stages of evolution. This three phase perspective is a unique and novel way of analysing the impact of the introduction of an information system in an organisational setting. These findings help introduce a sense of order and actionability into the usually abstract nature of structuralist investigations to produce a detailed picture of how the introduction of an information system can trigger changes in work routines, and in turn, changes in the IS.