Currently, the challenge of implementing a product data management system (PDMS) is how to ensure system integration and product data exchange is shared between heterogeneous systems. In this research, an integrated data models and implementation approach for PDMS is proposed that uses the STEP (Standard for the Exchange of Product) model data standard and schema as proposed by the Object Management Group (OMG). The objective of migrating these data schemas is to propose a standardized product data management (PDM) data schema that fulfils its functionality, including product structure management, configuration management, document management, workflow/process management, effectivity management, and engineering change management. The PDM-related data schema that is defined in the STEP standard, the PDM schema, and the Joint Product Data Management (JPDM) Enablers is identified, discussed, compared and migrated in this paper. To solve the barrier of product data exchange and sharing within and between enterprises, a robust and standardized PDM data schema fulfilling the functionality of PDM can be constructed with the proposed migrated data models. The implementation issues of a STEP-based system via these data schema are also discussed. With the proposed approach and architecture, the integrated data models fulfilling the functionality of PDM for PDMS, as well as the methods of implementing STEP-based PDMS, have been demonstrated.