This paper presents a method for enterprise modelling that enhances object-oriented modelling with concepts from Management Science and Business and Administration. It includes a framework that provides a set of conceptually integrated partial models, each of which is suited to represent a particular perspective on the enterprise - a strategic, an organizational, and an information system perspective. While the conceptual foundation is provided by a common object model and a corresponding meta object model, the partial models have specialized semantics and provide intuitive notations. An overall process model fosters a coherent coordination of the various activities to be performed during analysis and design. The activities themselves are described in detail referring to the partial models and to analysis and design techniques, some of which are integrated in the overall object model. The framework is accompanied by an integrated tool environment which controls a model’s integrity, provides various analysis techniques, and allows to navigate through a model. It will be shown that an enterprise model not only offers abstractions which are useful during the development of a corporate information system, but also some of them are well suited to support managerial decision making on an everyday base. Hence, an enterprise model can be regarded as a repository storing and managing concepts and resources directly related to a company’s information system, as well as general knowledge about a firm.