The Unified Modeling Language (UML) has been established as a standard in object-oriented software engineering, defining parts of a model and making systems more easily understandable. The results of modeling can be exploited in various ways. In this article, we want to propose two possibilities. Model examination defines strategies to ensure consistency in object-oriented models. Apart from that, it makes it possible to recognize and minimize errors already on the level of the individual models.Through the extension of the collaborations of the UML, we have also developed a new kind of description for various forms of reuse. This kind of description can be used for frameworks, patterns and idioms. For both innovations, specific elements were integrated in the UML modeling tool Object Technology Workbench OTW(r).