Abstract
Contrary to common belief, IT systems often disappoint the expectations to increase productivity and flexibility of work and value creation processes. Moreover, most IT design and implementation projects still fail or burst time and cost budgets to a high extent. After presenting significant empirical evidence for these phenomena, the paper reflects on the reasons for their persistence by developing a semiotic perspective on the processes of dealing with computer artifacts in organisations. This semiotic view allows understanding the processes of designing, implementing and using IT systems as efforts of structuring social practices in organisations. A typical case of enterprise resource planning system implementation illustrates this. Finally, a number of guidelines for an improved practice of designing and appropriating IT systems for effective use in organisations are derived from the theoretical reflections