Product information model and system integration based on generalized CAD

A product information model based on STEP, which mainly contains five parts such as general information model, structure information model, shape description model, physical feature model and management information model, has been studied. Its description method and exchange mode of neutral file are also researched. The model has the features of integrality, consistency, variety, flexibility and neutral mechanism. When used into the application instance of integration between CAD and PDM system, it has been proved that the model and neutral mechanism can help to implement integration of generalized CAD systems.