CAD and Part Association Overview

Formerly, CAD documents and Windchill parts were associated by links that were either active or passive. An active link meant that the CAD document structure builds the product structure and supports the passing of attributes between a CAD document and its associated part. A passive link means that the CAD document is one of possibly several that describe the Windchill part, but does not contribute to the product structure.

Currently, Windchill continues to support the passive link between a part and its deliverables. This is now referred to as a “content association”. However, the former active link is now differentiated into several functional types, depending on whether the association does one or more of the following.

It is important to recognize the ambiguous meaning of the term “representation”. When discussing association, representation means “represented in – or participating in – a structure as opposed to a “viewable representation” as seen in the Representations/Annotations table on a part’s information page.

When you perform an associate operation, several possible types of association are available. All of the following association types are available for CAD documents. Only the Content and Contributing Content types are applicable to dynamic documents or graphics dynamic documents.

• Owner—This association enables all functions: driving structure, contributing (passing) attributes, and representation. In other words, it indicates the primary representation that also drives the structure and the majority of the attributes for the part.

• Contributing Image—This association combines representation and attribute passing. Although a Contributing Image does not 'drive' structure, it participates in the product structure of a parent object. For example, a flexible component (cable) may occur, say, two times in an assembly, but routed differently in each case. While Creo Parametric requires separate model files for each routing, these models can be associated to a single part. One model file has an Owner link and the other has a Contributing Image link. The resultant product structure would show two occurrences of a single part. Association allows a maximum of one Owner link and one Contributing Image link to a part. However, additional configurations of the cable, if required, could be added using an Image link.

• Image—This association is for representation; for example, for copies of the primary CAD representation used in other CAD systems, such as a Creo Parametric CAD part model created from an Associated Topology Bus import of CATIA V5 data. As with the Contributing Image link, an object with an Image link participates in the parent product structure (but does not pass attributes).

• Content—This association is “passive,” meaning that the CAD document describes the part but does not drive structure, pass attributes, nor provide a representation. Examples would include manufacturing objects, process plans, layouts, and so on.

• An association between a part and the engineering drawing derived from its Owner-associated CAD model is automatically created upon initial upload. This association is labeled Calculated. It is not a modeled “link” in the database, but is an included association type when CAD documents are collected for actions.

Calculated associations are not supported for import/export.

Only one CAD document can have a structure-creating (Owner) link to a part. However, multiple CAD documents may have attribute or representation links, for example:

• Attribute contribution is supported for CAD documents with Contributing Image (one per part) and Contributing Content links (in addition to Owner links).

• Representation in structure is supported for CAD documents with Contributing Image (one per part) and Image links (in addition to Owner links).

There is no limit on the number of Content links to a part.

Dynamic documents and graphic dynamic documents can only be associated to parts by manually initiating the association action on a selected part object. Dynamic documents and graphics dynamic documents cannot form an Owner, Contributing Image, or Image link. Only Contributing Content or Content links are available for dynamic documents and graphics dynamic documents.

For more information see, Editing the Association of CAD Documents and Parts.

The association or disassociation of a part with a CAD document having a structure association (Owner, Contributing Image, or Contributing Content) causes the part object to be iterated.

• To create an associated product structure that is derived from a mature CAD model structure, with all or most associations established as the strongest (Owner) type, the Auto Associate Parts action is recommend. The Auto Associate Parts window does allow for fine tuning of the association type. However, it is simplest to use for establishing one-to-one CAD document to part associations, whether by association of existing parts, or by automatically generating new parts, as needed.

• Following the association of a part to a CAD document, the default system behavior is for the part structure to be built at the next iteration (checkin) of the CAD document. As building the part will cause its structure, attributes, and viewable representations to be updated, based on the association type, it is often beneficial to ensure the information is passed without waiting for the next iteration of the CAD document.

With Operation > Auto Associate > Build Part After Associate set to Yes (the default value is No), when the user associates a part to a checked-in CAD document, the system can automatically build the related part. That is, the build occurs at the time of the association edit or auto association, without requiring iteration of the CAD document.

The CAD document must be checked-in for the build to occur. If the CAD document is new or checked-out by you, the association will succeed, but a build of the part will not occur. A warning is provided in the Event Management utility for such parts which are not built.

When a CAD document (EPMDocument) that does not have an owner association to a part is submitted for publishing, the new representation is stored on the CAD document. If a CAD document has an owner association to a part, the new representation is stored on the part, and not the CAD document. When the owner association between the CAD document and the part is created after the CAD document is published, the following behavior can be expected:

• When navigating to the representation listing from the Part details page, the representation is displayed, however, it is a “read-only” representation. This representation cannot be deleted. When the associated CAD document is submitted for publishing again, the new representation is displayed in the Representation listing for both the CAD document and part.

Build After Check In — The preceding behaviors are seen when a CAD document is checked in with associated parts, and is submitted for publishing with the preference Build After Check In set to None. (The Build After Check In preference is located in Preference Management on the Windchill Utilities page at Operation > CheckIn Operation > Build After Check In.) The CAD document and part may appear to have an owner association. However, no association exists until a “Build Associated Parts” action is performed, which creates an owner association.

Multiple Owner Associations — When a CAD document with more than one owner association with multiple parts is submitted for publishing, the new representation is directly associated to the “Primary Owner-Associated Part”. This is the first part associated to the CAD document. All other associated parts in this case are referred to as “Non-primary Owner-Associated Parts.” If you want to copy the representation to the Non-primary Owner Associated Parts, use the Copy Representations to Described Parts set of preferences located in the Visualization section of the WindchillPreference Management utility.