Xastro - an Xml Based Space Data Exchange Framework

ION VS. REFINEMENT When modelling complex systems, one usually starts with an abstract model, which is refined in the course of gaining a better understanding of the problem domain. It is very difficult to come up with generic concepts that allow identifying relations between abstract and refined models since these concepts are heavily bound to the underlying engineering process. Thus, the concept of abstraction vs. refinement will be handled externally to the framework under consideration. However, at a later stage, suitable configuration management mechanisms could be included into the framework. This will also become an important issue when the full life cycle of engineering data is to be captured, as in the area of product data management (PDM). HIERARCHICAL DECOMPOSITION The concept of hierarchical decomposition is quite natural when handling complex systems. Starting from a high-level subdivision of the system into components, each component can then be further understood