Model driven IT systems development with code generation is today used in several, mostly technical, application areas. However, for large IT based Information Systems (ITbIS) it is still quite uncommon. An innovative case of low cost and high quality ITbIS is presented along with the model driven framework applied. This innovation is made possible by a coherent model driven approach with integrated method and tool support for the complete development and maintenance cycles of an ITbIS. For over 20 years and still, the FMV ERP system has been designed, extended and modified in pace with changes in the organization as well as disruptive changes in information technology.