1. A method for comparison of computer-based and data-processing models of a complex system, wherein a first model and a second model of the system are present, the models in each case model a system behaviour by way of predefined objects which represent activities and units within the system, and the method comprises the following steps: comparing both models and determining predefined objects of the first and the second model, which objects are associated with one another in each case, determining differences in attributes of predefined objects associated with one another, and issuing the determined associations and differences to a user.