Do you know Astah API?

The Astah series has anĀ Astah API.
You may be able to add features that are not in the standard using this. You may also be able to link with other software.

Divide project in various cases

Astah’s “Reference Model Management” is a very powerful function which allows you to import other project models as read-only. So you can work on your models using other project models without worrying about altering them. When there’re any updates on the original models, Astah automatically detects it and informs you, so that you won’t miss to sync and can work with the latest models all the time.