Model Driven Architecture (MDA)

The model driven architecture (MDA) defines a phased model for going from descriptive models via platform independent models to platform dependent models and then to the final platform itself.

Especially the left side of the MDA diagram is rather nebulous. Could it be that this could be the area of domain analysis (generative computing), conceptual domain analysis (M. Fowler, Introduction to UML) or Domain Specific Languages? Also interesting is what kind of information needs to be added to the various models to enable the transformations to levels with less abstraction. Will this system allow complete tracing - e.g. in case of errors at lower levels to go back through all the models? The annotations will play a critical role here if they are not part of the model itself.