A method simulates aspects of a system. The method includes: (a) creating models of a system, wherein each individual model describes a specific aspect of the system, (b) determining for each model an initial first data record containing specific data used only by the model and an initial second data record containing common data used by the model and at least one other model, (c) selecting a first model and a second model, (d) determining updated first and second data records on the basis of the initial first data record for the first model and the initial second data records, and (e) determining updated first and second data records for the second model based on the initial first data record for the second model, the updated second data record for the first model and the initial second data records for all of the models except for the first model.