E-commerce based companies rely on the effective use of the information systems used to support their processes. Accordingly, managers place a great emphasis on the success of projects to introduce such systems. However, research increasingly suggests that project success may not be as objective as one would assume or hope. Quite contrary, as our work will show, project success is often constructed by the stakeholders involved in the project. Extending prior research, we investigate how different groups of stakeholders construct their own perception of project success and how these different perceptions influence each other. Through our work, we provide management with insights into threats to a reliable project management approach for critical IS projects and identify a few major drivers that need to be accounted for to make sure that such critical projects really are successful.