NIST Engineers Support Vendor Implementations of STEP to Evolve Digital Manufacturing

In September 2024, NIST Engineers Rosemary Astheimer and Allison Barnard Feeney participated in meetings held by the MBx Interoperability Forum - a collaborative testing initiative between AFNeT Services; PDES, Inc.; and prostep ivip since 1999. The forum serves as an industry platform to express requirements and work with CAD and translation vendors to develop implementation strategies that align with ISO 10303 STEP (Standard for the Exchange of Product model data).

STEP is a neutral file format containing essential product information for manufacturing and quality measurement to ensure it is fit for purpose in a machine-readable form. This supports automated devices, such as Computer Numerical Controlled (CNC) machines for manufacturing and Coordinate Measuring Machines (CMM) for automated inspection, significantly reducing human error, enhancing efficiency, and lowering operational costs. The committee’s recent focus is to provide traceability of product requirements over the lifecycle of a product. As information moves through the supply chain, different systems adapt the data to be fit for purpose. NIST research shows that associating universally unique identifiers (UUIDs) with key engineering requirements enables traceability, leading to NIST’s recommendations to incorporate UUIDs in product data standards and commercial engineering software.

Stakeholder input indicates that the lack of a mechanism to trace a design’s history, such as UUIDs, has resulted in a major roadblock to realizing the full potential of a model-based enterprise.

One example of UUID usage is an OEM requesting a change to an initial design that was provided to a supplier. The OEM submits a change order to the supplier, identifying the detailed information that was changed and its related UUID. The Supplier makes the change and returns the data, with updated information associated with the same UUID, to the OEM for an unambiguous communication of the change.

A new NIST CAD test model developed by Astheimer prompted extensive discussions on the relationship to design features and UUIDs. For example, how are UUIDs applied to a pattern of holes? The team discussed the implications of assigning a UUID to each individual feature in the pattern or if a UUID should be applied to the parent feature and another UUID applied to the pattern parameters. The team will continue to work through proposing solutions and testing them in the upcoming test round. Once vetted by the members of the MBx-IF, the results will be brought to the STEP committee to consider adding to a future edition.

NIST supports many other activities within the group, such as authoring recommended practices to supporting vendor implementation and authoring Computer-Aided Design (CAD) models made publicly available for testing. While STEP has been widely implemented, new requirements are continuously identified as industry continues to expand its use of the standard in earnest.