During normal operation of the systems and networks, activity data is collected (step 3-i, figure ). After a certain period of time the information is transferred to places where the models are generated. The type of information gathered in this step totally depends on the method used in step 3-ii which is the most challenging task of the process: the actual automated generation of models. Several methods have evolved to support or replace manual generation which mainly suffers from the enormous effort it imposes on the administrators during actual model creation and also to keep them up-to-date. Alternative automated approaches are: