To manage the evolution of the organisational structure and the IT- systems of an enterprise different kinds of models are used. Key to this paper is the observation that despite the promises and some elaborate approaches to corporate modelling, many organisations fail to implement a stable long-term activity to keep its models current. A number of influences are identified. Very important is the motivation of the involved persons, mostly the modellers and the support of their work. This comprises technical and organisational aspects. Many of the aspects are conflicting factors. After discussing them, a practical example is outlined and explained along the lines of the reasoning in the first chapters.