Products that are large, complicated, expensive, and perform a critical function are often configuration managed throughout their service life. Each shipped unit is identified by a serial number and product configuration records are kept when new parts are retrofit to that unit in the field.

To support this use case, Windchill provides the ability to save specific part structure configurations and create serialized copies that can be revised and edited to record the field changes to products that are in service. This capability utilizes special database objects called part configurations and instances.

Product designs are changed continually throughout the product’s life cycle. A part configuration is a baseline of a part structure containing all of the latest released part versions at a specific point in time. The part configuration is copied to create one or more individual serialized part instances whose part structures can be modified independent of the current design part structure, the part configuration, or any other part instances.

A part instance is said to be incorporated on the day it is assembled and ready for shipment. The part instance can be revised and its configuration changed each time new parts are added to that serialized copy of the product in the field. A new incorporation date is specified for the new part instance version. A part instance can also be unincorporated and retired from service.

A part instance can use other part instances within its part structure. The serial numbers of the parent and child instances are associated to each other using allocation. A child part instance can be deallocated from one parent part instance, rebuilt, and reallocated to another parent part instance.