Part number

Identity is different from model state#

A model can show several states of one physical item without needing several part numbers. A spring shown compressed and free is still the same spring. A bracket offered in three manufactured sizes normally needs three identifiers so the BOM, order, drawing, and inspection record select the intended item.

Onshape's Configured Properties documentation demonstrates both cases. It allows part numbers to vary by configuration, and it allows a configuration input such as spring compression to be excluded from properties when that state should not change BOM or release identity.

Part number versus revision#

The part number answers which controlled item is being referenced. The revision answers which approved definition of that item applies. Changing a drawing note or feature may advance a revision without creating a new item. A change that breaks interchangeability, creates a separately orderable variant, or follows the organisation's new-item rules may require a new part number.

Those rules are organisational and contractual, not a universal CAD setting. Apply the numbering and change-control policy used by the product-data-management, purchasing, manufacturing, and service systems.

Configured items need explicit release data#

Onshape's release guidance treats an included configuration as a unique revisionable object and makes only released configurations available for reuse from that released version. This allows several numbered family members to share one native model, provided every downstream system preserves the configuration-specific identity.

If the BOM, drawing, export, or supplier package cannot distinguish those configured items reliably, separate files or item records may be safer than relying on a native-model selector.