Searching for MPN Materials 
You can search for MPN materials using the input help.
In order that this function does not impair system performance, the indexes BMA and MPN must exist in the table MARA (material master). Once you have generated the indexes, they are updated by the system.
You generate an index as follows:
From the system menu, choose
Choose
Change the database table MARA.
Choose
Choose the index BMA (number of the internal material master).
Set the indicators Non-unique index and Index to all database systems .
Activate your changes.
Also perform steps 5 to 7 for the index MPN (manufacturer part number/number of a manufacturer).