Advantage of model relations?

Hi,

we are using Java Bean models for our web dynpro project. Therefore we generated a model of type "Java Bean model". In the import dialog of the model generation we detected the possibility to define model relations according to the relations used in our java beans. We ended up with a huge model with several model classes. Everything looks fine but I'm seriously asking myself what the big advantage of this approach is. Asuming that the Java bean model will change sometimes I have to reimport the model and have to define all these relations by hand again! So I don't really see an advantage but I guess that I have lost sight of advantages.

I really would appreciate any replies showing me the advantages. Maybe there are also helpful documents.

Regards,

Marc