In many cases different part numbers are assigned for variations of color or other trivial differences that wouldn't otherwise affect the definition of the device. DeviceDefinition should support multiple part and model numbers. In order to distinguish which part number goes with which variant, an optional CodeableConcept should be added.

Therefore, proposed structure:

• partNumber 0..*
  • variation 0..1 CodeableConcept
  • number 1..1 string
• modelNumber 0..*
  • variation 0..1 CodeableConcept
  • number 1..1 string