Working with Design Layers › Design Layers › Design Layer Hierarchy

Design Layer Hierarchy

Generally, in a design layer hierarchy, different model types are used for a distinct purpose in the application development lifecycle. However, you must be able to develop and link related models in different design layers. Within each design layer, you must be able to make and record design decisions that transform the structure from one layer to another. Finally, you must be able to maintain the links between the models in different design layers and to synchronize changes made in different layers while maintaining the appropriate structures in each. The combination of linking models in different design layers using model sources and applying transforms within a model provide the capability to create a successful hierarchy.

For example, a logical model may represent business requirements and rules. From that model, a generic physical model may be derived, in which physical constructs are designed for a generic database. Once the generic physical model is considered stable, you can derive from it multiple database specific models. In this way, the generic physical model becomes the standards model.

A variety of features are necessary to support the separation of model types and to keep related models linked and in sync.