Meta-models Are Models Too

This article introduces multi-formalism modelling and metamodelling to facilitate computer assisted modelling and simulation of complex systems. To aid in the automatic generation of multi-formalism modelling and simulation tools, formalisms are modelled in their own right, at a metalevel, within an appropriate formalism. This approach is implemented in the interactive tool ATOM3 (A Tool for Multi-formalism Meta-Modelling). This tool is used to describe formalisms commonly used in the simulation of dynamical systems, as well as to generate custom tools to process (create, edit, simulate, ...) models expressed in the corresponding formalism. ATOM3 relies on graph rewriting techniques to perform the transformations (modelled as graph grammars) between formalisms as well as for other tasks, such as code generation or simulator specification. The Finite State Automata (FSA) formalism is used to demonstrate the concepts of meta-modelling as well as model transformation (in particular, simulation of FSA models). The issue of a neutral model exchange and re-use format is addressed in the context of meta-modelling. Core XML is proposed as a standard external format. Thanks to the power of the meta-modelling approach, DTD, XMLSchema, and XSLT specifications may be replaced by models, externally represented in core XML, in appropriate formalisms (Entity Relationship for syntax and Graph Grammar for transformation respectively).