Two key differences between Rational Rose® and the new UML modeling products involve models and model management. While you can now create and open multiple models simultaneously, you can only open one model at a time in Rose. Further, in the new UML modeling products, you can only control models at the model level; you do not use the subunit concept to refine and break up a model in multiple levels and sections.
You can have multiple projects and models open at the same time in the new UML modeling products. You can use this multi-model capability to work at different levels of abstraction, while still maintaining traceability across models. The multi-model approach is a key paradigm shift because you can only open one Rose model at a time, which is sometimes cumbersome when you need to work and modify several related models in unison. Now you can open multiple models simultaneously and tie them together at various levels of your model hierarchy through shortcuts, relationships, and cross-references between models.
Before you learn more about the model management capabilities in the new UML modeling products, it is important to review how subunits work within Rose.
Subunits in Rose
In order to share parts of a Rose model with multiple users, or to simply reduce the size of a single model, you can break up a model into individual chunks, commonly referred to as subunits (subunits are called controlled units when stored inside a configuration management system). Subunits help you manage a model by dividing it up and breaking it into smaller, more manageable sections. It is very common for software development teams to work in parallel by sharing out and placing controlled units in a configuration management system such as IBM® Rational® ClearCase®.
For example, when you create a subunit from a package, its contents are moved from the model file and stored in the new file. The new file contains the following information:
Model management in the new UML modeling products
The model management approach in the new UML modeling products is a major change from Rose. In the new UML modeling products, you manage and control your models at the model level only; the concept of subunits is not carried over from Rose. While the new UML modeling products do not use subunits, it does not mean that the information stored in subunits is lost upon import.
When you import a Rose model that references subunits, you have two options to consider; you can choose to have packages (CAT) and component packages (SUB) subunits import as separate models, or you can choose to have all subunit content import as packages inside the imported model.
While the model management capability between each tool is different, you can still achieve the same results by dividing your model at the model level instead of at the subunit level.