1. A computer program product comprising one or more physical computer-readable media having thereon computer-executable instructions that, when executed by one or more processors of the computing system, cause a computing system to perform the following: an act of accessing a hierarchical structure of model elements; and for at least one of the model elements, an act of determining that the model element should be changed from a first model element type to a second model element type; and in response to the determination, an act of automatically changing a model element from a first model element type to a second model element type while maintaining an ancestral relationship status of the model element within the hierarchical structure of model elements.