UML 2.0 in a Nutshell

The Models of MDA

Models play a big role in MDA. As a framework for building systems, MDA abstracts systems into abstraction layers. Traditionally OOAD had analysis, detailed design and code roughly representing a system's business perspective, the architectural/technological perspective, and the implementation perspective. MDA adds one abstraction on top, representing the business context of the system. Figure A-1 shows the different abstraction layers and their associated MDA models. Abstraction increases toward the left and concreteness increases toward the right. Concrete models outnumber abstract models. In general, the abstract begets the concrete; as each model becomes more concrete, it realizes the abstractions with respect to one technology or platform. The inverse, making abstract models from the concrete, also known as reverse engineering, rarely happens, except when the starting point is code. Even then because the system must support a business, starting from the business needs is generally more appropriate.

Figure A-1. An example of MDA models and their relationship

The abstraction models match well with the conceptual layers of a system:

Computational-independent model (CIM)

The CIM represents the highest-level business model. The CIM uses a specialized business process language and not UML, although its language could well be derived from the meta-object ...