In top-down design (TDD), you can modify the Windchill product structure and then rebuild the CAD structure to synchronize it. This is sometimes referred to as a reverse build: building the CAD structure from the product structure. Once built, the CAD structure is said to be annotated and in sync with product structure. To continue the cycle, you must open the CAD structure in its CAD authoring tool (Creo Parametric) and confirm the changes pushed to it from the Windchill product structure. Checking in the CAD structure completes the TDD cycle.

For more information, see Top-down Design

It is possible to update (check in/out) the CAD document even if the user does not have sufficient access to the part. In addition, the action of associating or disassociating a part and CAD document requires an iteration of the part.

The top-down design and flexible product structure editing is dependent on the occurrence link information being instantiated properly. This is mostly applicable to the proper control over the deletion of parts from a CAD-driven product structure.