The research group Model-driven Development is headed by Erik Burger. Researchers at DSiS use model-driven methods and tools to model software properties such as performance, reliability, and maintainability, but model-driven methods have also become a branch of research in its own right at DSiS. The members of this group investigate how model-driven paradigms such as model transformations or views can be used to increase consistency in the design and operation of cyber-physical systems. These efforts are concentrated in research on the Vitruvius approach, which provides methods to create Virtual Single Underlying Models (V-SUMs). These represent all available information on a system under study, and are the base of consistency definitions and rules for the repair of inconsistencies.