The design of large generators deals with complex problematics of electromagnetic, thermal, fluid dynamic and structural calculations, which have to be run all simultaneously. To achieve this objective, Ansaldo Sviluppo Energia (A.S.EN.) has developed a test-case of 2D FEM model of a generator in collaboration with Enginsoft Technical Support team. Using the Ansys Workbench simulation environment, the output dataset of the magnetic calculations (electromagnetic forces and losses) have been used as input dataset for the thermal and structural calculations. Furthermore, by means of Open Source programming language, a prototype user-friendly interface has been implemented in order to permit the designer to be able to work with the FEM model, without requiring specific ability on using FEM software. In the paper are presented the preliminary features of this user-friendly interface and the usefulness of Ansys Workbench for FEM Multiphysics modelling.