I need to enter the below relation in every part and assembly present in the a particular assembly.
currently i need to enter the relation manually in every part and i have approx 300 parts in every assembly.
Just the opposite of me, we remove the .prt and .asm from PTC-COMMON_NAME.
For new parts, put that in your start_part.prt template file.
For existing parts, you may be able to do it with ModelCheck in Batch mode.
It used to be that such a relation would cause error messages once model is checked in (PTC_COMMON_NAME becomes a "locked" parameter, changeable only in Windchill). Did things change with the latest Windchill?