Modeling becomes the most prominent method of dealing with software complexity. Models for software systems can be created on different levels of abstraction and in different phases of the software development process. In order to manage these various models effectively we need to apply methods for keeping them coherent and traceable. The current paper proposes a method for defining and executing transformations between models written in the currently most popular modeling language (UML). We propose a general purpose transformation language that allows for specifying transformation mappings between different models. This language has a visual (MOF-based) notation and allows for defining transformation templates and rules. With this language, the software developers are capable of determining traceability links between individual model elements. Moreover, the transformations can be executed automatically to high extent, with the use of a dedicated tool that extends a standard UML CASE tool.