In section 2.3 we defined a transformation as the generation of a target model from a source model. This means that transformations are purely processes. The process is described by a transformation definition , which consists of a number of transformation rules , and is executed by a transformation tool . In an MDA approach there are a number of features of the transformation process that are very desirable. We name them in order of importance:
Each of these features puts demands on the transformations. In the next sections, we further investigate the desired features. Section 7.6 describes the implications of the features on transformations.