Abstract: The invention relates to a method for preparing models of technical devices, wherein each technical device comprises units that are connected to each other by means of connection points, wherein, when performing the method, at least one structure made of units connected to each other by means of connection points comprising similarities for all technical devices is integrated and automatically described as at least one mutual module (8) for all models.

Abstract: The invention relates to a method for describing a behavior of a technical apparatus, which has a number of units, a system graph (8), which comprises a number of levels, being automatically generated for the technical apparatus, in each case a k+1th level being subordinate to a kth level and at least one subordinate unit in the k+1th level being associated with a superior unit from the kth level, a technical behavior of the at least one subordinate unit being summarized in each superior unit. Furthermore, the invention relates to a method for the diagnosis of a technical apparatus.