Additional Windchill Capabilities > Service Information Management > Customizing Windchill Service Information Manager and Windchill Service Parts > Custom Product Models
  
Custom Product Models
Windchill Service Information Manager service structures can have a configured relationship with custom product models. The custom product models must be a subtype of WTPart, identified as Part in the Type and Attribute Management utility. A product model subtype of Part would typically define a common base subtype with distinct root and instance child subtypes.
Windchill needs to be configured to find these product models in the sis.properties.xconf file.