Initial release of ISO 10303 or STEP has been published. STEP is the first attempt to standardize the representation of whole product model data including geometry, product configuration, drawing, material, and other aspects. Its status and future tasks are discussed in this paper. First, the models of STEP and its methods are explained. Its main features are: • Aspects of product data are represented in an integrated way. • Detailed definitions are provided using computer-interpretable description language. • Definitions of product are provided hierarchically as integrated Resources and Application Protocols. • The method of the conformance testing is provided as a part of the standard. Several issues still remain to be resolved, including he cooperative use of standards, the grand design of STEP, new features, and the method of good modeling.