This paper presents a novel way of thinking about how information systems are used in organisations.Traditionally, computerised information systems are viewed as objects. In contrast, by viewing the informationsystem as an actor, the understanding of the structuration process increases. The user, beinginfluenced by the ERP (Enterprise Resource Planning) system and giving it an actor role, thereby alsoconfers agency on the ERP system; through its very use it influences actions and thus also the structure.Based on a case study of ERP use in an ABB company over a decade, five different roles played by theERP systems were identified. The ERP systems acted as Bureaucrat, Manipulator, Administrative assistant,Consultant or were dismissed (Dismissed) in the sense that intended users chose to avoid usingthem. These terms are defined in the full text.The purpose of this approach here is not to “animate” the information systems, to give them life or amind of their own, but rather to make explicit the socially constructed roles conferred on them by usersand others who are affected by them. On this basis, it is possible to suggest how the roles can help usopen up new areas of exploration concerning the fruitful use of IT.