Context-Sensitive Multilevel Instantiation for Space System Development

In model-based systems engineering, engineers from different domains collaborate on central system models. They develop abstract ideas to concrete implementations. To organize information exchange and to prevent misconceptions and conflicts, strict rules for model manipulations are required.

Multilevel modeling is a technique that can map systems development from abstract to concrete. It enables to iteratively use existing model elements to describe new ones, which are added to more concrete model levels. Editing constraints for such system models require foreseeing the following model levels. However, in systems engineering models have to be adjustable to changing requirements and projects of different complexities. As a result, depending on the application context, system models contain different abstraction levels.

This thesis presents context-sensitive multilevel modeling, which introduces a separate context model. This context can be utilized to specify context-based constraints. With, e.g., a process model as context, it is possible to specify that elements are only editable in a specific process phase. Changing requirements can be handled by updating the context model. Furthermore, context-based constraints are understandable for non-experts in modeling.

This thesis shows feasibility of context-sensitive multilevel modeling by applying it to systems engineer- ing projects of the space domain. Besides editing constraints, these projects demand domain-specific editors and artifact generation.

Development of a Graphical Modeling Language for an Event-Driven Real-Time System

To compute a large amount of data in real-time systems several software components and algorithms need to be connected. The Tasking Framework enables communication between components and the event-driven execution of such components. Due to the complexity of the configuration of this framework, a graphical modelling language was developed to generate the required source code.

This thesis describes the evaluation of existing graphical modeling languages and, eventually, the definition of a language specialised in the scope of event-driven communication. Multiple diagrams facilitate the description of the software from various perspectives.

To implement a diagram editor, several frameworks were compared and, finally a combination of the graphical modelling framework and EuGENia was selected. The editor allows only well-formed combinations of diagram elements and provides a validation of the element parameters.

To adapt the model-driven development to the project-specific requirements, the language, editor and code generator support the dynamic creation of new elements using ontological concepts.

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