Scholars have not found a common understanding of information system (IS) project success nor does a common measurement approach exist in empirical research. A plausible cause for the lack of such an agreed on definition is that a generally accepted definition of IS project success practically cannot be derived due to stakeholders’ different perceptions of success. Therefore, we develop a situational model for the group of IS projects’ contractors. We gathered data from 52 IS projects managers and apply PLS path modeling to determine the relevant success dimensions from their subjective perspectives. Our results show customer satisfaction, process efficiency, and functional requirements as the three most important dimensions for contractors. Scholars and practitioners should shift from measuring IS project success in terms of adherence to planning to an approach adapted to the specific terms of the project under consideration and the stakeholder group addressed.