Model Coupling and Integration via XML in the M3 Simulation

Complex real-world systems are currently developing into a decisive instrument for IT-supported problem solving for a great number of problems posed by science, economy and society. Like in many environmental simulation systems the Man Model Measurement (M3) Simulation (http://mmm.first.fraunhofer.de) contains numerous single scientifically founded models coupled to each other to reflect the complexity of our world. The unpredictable human factor is considered by actively involving real people into the simulation by a Virtual Reality framework. The evolution and enhancement of the M3 system will be provided by an open software API. This paper will focus on the control and the data communication between the distributed simulation models that are realized by specialized markup languages which employ the XML technology for easy extension and validation. The input and output data of the models is represented by an XML data model that includes also the physical and mathematical meaning of the transferred data so that different models can be easily coupled by connecting their XML formatted input and output streams, e.g. via sockets. The initialization parameters and the relevant output data of the models can be stored in an SQL database (MySQL) which can be accessed by a web interface or directly using JDBC. Legacy Code is included in the simulation system using wrapping technologies