Product Data Management (PDM) systems are gaining importance as central databases used for enterprise integration in the manufacturing domain. Multiple standards and standards-track specifications already exist for PDM, including the PDM Enablers standard from the Object Management Group(R) and the "PDM Schema" derived from ISO 10303, the ISO Standard for Exchange of Product model data. In the interest of testability and standards harmonization, we developed a "harmonized" testing approach that allowed test scenarios defined for one specification to be combined with test data defined for the other. The resulting tests could be realized with approximate semantic equivalence in both contexts, and the resulting lessons about testability are now having an impact on standards development.