Evolving Information Systems: Meeting the Ever-changing Environment

To meet the demands of organisations and their ever changing environment, information systems are required which are able to evolve to the same extent as organisations do. Such a system has to support changes of all timeand application-dependent aspects. In this paper, requirements and a conceptual framework for evolving information systems are presented. This framework includes an architecture for such systems, and a revision of the traditional notion of update. Based on this evolutionary notion of update (recording, correction, and forgetting) a state-transition-oriented model on three levels of abstraction (event level, recording level, correction level) is introduced. Some examples are provided to illustrate the conceptual framework for evolving information systems.