There are two kinds of model transformation. Intra-formalism transformations transform a model into another model in the same formalism. The result of this transformation is usually optimized for modularity or efficiency. Inter-formalism transformations transform a model into a new model in another formalism. The new model can thus be reused in the systems designed in the other formalism. The possibility of such transformations gives a meaningful comparison of expressiveness between the two formalisms. Another benefit of inter-formalism transformations is that, by transforming a model into a more extensively studied formalism, the model checking tools of that formalism can be used to prove certain properties of the model.

The model transformations discussed in this thesis are inter-formalism transformations. Intra-formalism transformations are not discussed.

Spencer Borland in his Master's thesis [9] has shown an approach with which statecharts models can be transformed to DEVS. This helps prove that DCharts can be transformed to DEVS, because DCharts are a modular combination of statecharts and DEVS. More transformations between statecharts, DEVS and DCharts are discussed in the later part of this thesis.