ABSTRACT The performance data of most Siemens heavy-duty gas turbines which have been built in the last 20 years are stored in so-called typefiles. These typefiles contain the description of the thermodynamic operating behavior for each gas turbine type using several component maps, e.g., for the compressor, the turbine and the combustion chamber. In addition to all available high-accuracy performance test results, modern IT technology enables the user to handle a tremendous volume of measured data via remote access. This allows the user to determine and to guarantee the performance of modifications and upgrades with sufficient precision, even for older gas turbine types. The method for automated generation of typefiles based on the entire volume of available data and its corresponding Matlab ® based software solution are the focus of this contribution. Although this method offers a very promising source of data from various sites, the obtainable data sets usually do not cover the entire temperature and rotational speed range that is necessary to create a map suitable for all requisite operating conditions. Thus, theoretically-based additional information combined with special extrapolation methods are necessary