Definition of the PIM to PSM Mapping

The basis of defining a mapping that allows full and automatic translation of the PIM models, expressed in xUML into the implementation is to build an xUML model of the translation system itself and execute it! The elegant conceptual coherence of employing xUML both in the business-modelling realm and in building the translator means that a minimum set of new skills has to be learned.

Figure 3 shows the basis for defining the mapping from PIMs (expressed in xUML) to their platform specific implementation. "Ordinary" analyst models (level 1) are used to populate the meta-model of xUML (level 2), which has all the necessary processing defined (remember it is an executable model in its own right) to populate a model of the implementation (level 3). This final model, which again is expressed in xUML, is executed to produce the implementation. The analyst models (level 1) are augmented with tags that act like "compiler directives" to the translation system and allow such facts as limited instance populations to be exploited in order to produce efficient target code.

Figure 3 - Mapping PIM to PSM Tool Support