Abstract
Being an information modeling language to support the STEP (Standard for Exchange of Product Model Data), EXPRESS has been developed to share and exchange product design, manufacturing and production data in product life cycle. Also being the de-facto standard of data representation and exchange over the Web, XML (eXtensible Markup Language) has been widely applied in Web-based engineering applications for product data exchange and share. It is essential to integrate EXPRESS data model and XML data model in engineering data modeling. EXPRESS-G is the graphical representation of EXPRESS and can serve as the conceptual design of Web-based engineering data models. Fuzzy engineering information is inherent in many engineering activities. In order to explicitly represent and handle fuzzy engineering information, this paper introduces an extended EXPRESS-G data model for different kinds of fuzziness modeling. After presenting the formal descriptions and corresponding representations of the fuzzy EXPRESS-G data model, the paper investigates the formal transformation from the fuzzy EXPRESS-G data model to the fuzzy XML model. The formal transformation approaches proposed in the paper are demonstrated with engineering application examples.