In Teamcenter, the Item ID uniquely identifies an Item. Beginning with Teamcenter 10, the property used to make an Item business object unique can be extended to include more than just the Item ID (for example, Item ID and Type). When this new Teamcenter functionality is deployed, Solid Edge is able to reuse the Item ID for instances of different Item business objects (including Item, Design, Drawing, and Document). This functionality enables you to create multiple related items using the same Item ID, for example, when you want to refer to a design and drawing using the same Item ID.
Prior to Teamcenter 10, this was not possible because both design and drawing types are children of the Item type and are both considered items. Now, using the Business Modeler IDE in Teamcenter, you can create multifield key definitions per domain or object type.
Multifield keys define what makes an object unique in the database. The default multifield key definition for Item business objects is:
Item{item_id}
The value of the item_id property is the object’s unique ID.
In the case of design and drawing, you can define the unique key for design business objects and their children as Design{item_id} and for drawing business objects and their children as Drawing{item_id}. When these definitions are applied, it results in a unique key identifier for each instance of an object type in the database, even though the different object types can share the same Item ID. You can also create a unique key by adding a property in addition to the item_id property, such as object_type. For example, Design{item_id,object_type}.
You create a business object’s unique key definition using the MultiFieldKey business object constant in Teamcenter. A list of properties available for each business object type is provided in the Available Properties dialog box when you create a multifield key. For more information about creating multifield key definitions, refer to the Configuring business object identifiers with multifield keys portion of the Teamcenter Business Modeler IDE Guide.
The multifield key is composed of a domain name (the name of the business object type) and a combination of one or more of the business object’s properties:
domain{properties}
For example, in the Design{item_id} key, Design is the domain.
All business object types with the same multifield definition constitute a domain. Because children business object types (design, drawing) inherit the key definition from their parent (Item), they belong to the same domain as the parent business object unless a different multifield key definition is created for a child type. Custom business objects also inherit the key from their parents.
For more information about multifield key domains, refer to the Multifield key domains portion of the Teamcenter Business Modeler IDE Guide.
Prior to Teamcenter 10, only the Item ID could be used to uniquely identify an item. By using multifield key definitions, instances of different Item business object types (such as items, designs, drawings, documents, and specifications) can use the same item ID. When these definitions are applied, it results in a unique key for each instance of an object type in the database, even though the different object types can use the same item ID.
Redefining what makes an object unique in Teamcenter impacts what is required to create an object though Solid Edge Embedded Client. Properties that comprise the multifield key are identified in common property dialog boxes such as the New Document dialog box with a gold asterisk 
. The gold asterisk indicates the property (cell) is an input to the multifield key and the property is required.
When using multifield keys, your experience with Solid Edge can change from the default in the following ways:
Common property dialog boxes such as the New Document dialog box may require additional property definition (as indicated by the gold asterisk ).
The Filename is now the Item ID with a unique system-generated number appended to it.
<item ID>-<unique number>.extension
Searches based on the item ID can now return more than one result. If you search for an item ID that is used by multiple objects, the Search dialog box displays more than one result so that you can choose the desired object from the list of all objects with the same item ID.
Tip:
As a best practice, do not map the keys that make an object unique when you use the mapped properties functionality in Solid Edge Embedded Client.