System engineering is a complex discipline[1], which is becoming more and more complicated by the heterogeneity of the subsystem components[2] and of the models involved in their design. This complexity can be managed only through the use of formal methods[3]. However, in general the engineering of software in such systems leads to a need for a mix of modelling languages and semantics; and this often leads to unexpected and undesirable interactions between components at all levels of abstraction[4]. There are currently no generally applicable tools for dealing with this heterogeneity of interactions in the engineering of complex systems.