The Part Number is an optional 40 character alpha numeric field that is used to identify the job's part number to users.   Duplicate part numbers are allowed for jobs that are not template jobs, but a template job must either have a blank part number or a unique part number.

Part numbers can be used in the Multiple Jobs Editor to replace or refresh one or more job routings.

The "Part Number" term can be changed to whatever term you would like to use.  Part numbers can have a masked input.  You can search and sort on the part number and the part number can appear on graphs, displays, and reports.  You can hide the part number so it does not appear in DMS if you do not want to use this field.  The Part Number term, option to hide, and optional mask is entered in Terms and Settings.