Simulation and animation of visual languages based on typed algebraic graph transformation

In recent years, visual models represented by graphs have become very popular in systems development, as the wide-spread use of UML and Petri nets proves. Visual modeling techniques provide an intuitive, yet precise way to model the structure and behavior of systems at their natural level of abstraction. Validating model behavior is one of the main aims of visual behavior modeling. To express the semantics of visual models, the transformation of graphs plays a similar central role as term rewriting in the traditional case of textual models. The area of graph transformation provides a rule-based setting to define the syntax and semantics of visual models. The well-founded theoretical results support the formal reasoning about graph-based models at all levels. The main objective of this thesis is to improve the validation process for visual behavioral models by providing a formal framework and tool support for simulation and animation based on graph transformation. To attain this goal, we propose to use animation views for simulation instead of the notation of abstract diagrammatic languages. Animation views allow to simulate visual model behavior in the layout of the model’s application domain, at a freely chosen level of abstraction. Thus, they provide better insights of model behavior and lead to an earlier detection of inconsistencies and possible missing requirements in the model. Moreover, animation of scenarios may be used, i.e. scenarios may be visualized as smooth movements. In the graph transformation framework, the model behavior is given by a graph transformation system (the simulation specification) typed over the visual language alphabet. An animation view defines the visual model’s application domain by extending the alphabet. A simulation specification is mapped to an animation view by so-called simulation-to-animation model-and-rule transformation (S2A transformation). The formal description of simulation, animation and S2A transformation is based on the double-pushout approach to typed graph transformation. The formal basis is used not only to formalize visual models and their animation views, but also to reason about the semantical equivalence of the visual model’s representation in the animation view. Furthermore, the thesis describes the design and implementation of a prototypical tool environment for simulation, animation view definition, S2A transformation and animation. The existing generator for visual environments, GENGED, supports already the definition of visual modeling languages by type graphs and syntax grammars. The extensions of GENGED allow the definition of simulation specifications, scenarios, and animation views. S2A transformation is realized by applying so-called meta rules to the rules of an existing grammar. By the specification of continuous animation operations using the new animation editor, animation scenarios are visualized as smooth movements instead of discrete simulation steps.