  When looking through the proceedings of the recent Simulation
Interoperability Workshops, a lot of papers - some of them even awarded by the
committee - are dealing with alternative concepts outside or beyond the High
Level Architecture (HLA): Web Services, the extensible Markup Language (XML),
Java Beans, Simple Object Access Protocol (SOAP), etc. Similarly, requirements
driven by interoperability issues have resulted in the need to use meta
modeling, adaptive models, and common repositories. The use of the Unified
Modeling Language (UML) as a model description language is also rapidly
becoming a standard. All these concepts have relations to the HLA, but they are
not part of it. There seems to be the danger that HLA is overrun by respective
developments of the free market and will become irrelevant finally. ... This
paper introduces the MDA concept and shows, how the HLA can be integrated to
become a standard stub for simulation applications of legacy systems, systems
under development, and systems of the future.
