Abstract Models

In contrast to the environmental models dealing with objects directly mappable to real world components, the main elements of abstract models are classes providing an abstraction of the specialties of real environments. The dependencies between those classes are also specified on that level of abstraction. It is easy to see that environmental models actually are instantiations of abstract models, in regard to objects as well as their dependencies.

  

Figure: Simple abstract service dependency graph

Abstract models are normally generated manually--either by the vendor of the corresponding objects in the real world (e.g., the developer of an application provides a model showing the dependencies to other applications and the underlying system), or by the suppliers of management tools that are based on reasoning on such models. Just like environmental models, abstract models are suitable to express knowledge about higher layers, e.g., to model services. They do not depend on environmental specifics, but only express general or principal dependencies.

The model shown in figure looks similar to the previous one. However--as each node now depicts a class--both web clients are covered by a single ``web client'' element. Following object oriented principles, the nodes' and edges' attributes are now replaced by definitions for allowed, respectively needed attributes.