The model based approach uses graphics and pictures in supporting domain experts to express their knowledge, as this has been successful over the last decades when it comes to expressing knowledge. Graphical models have the advantage that besides the intuitive expressiveness of diagrams, there is a formalism that describes the meaning of the diagram.
The Next Generation Modelling Framework starts with the premise that domain experts use a variety of graphical modelling languages. A business process for example can either be modelled using EPC, BPMN, ADONIS® or any other business process notation. Similarly, an IT-landscape can be modelled in the UML or in ADOit® notation. Each of the above modelling languages has a different format, a different level of expressiveness and a different graphical representation, but shares some parts of the same knowledge.