Hi Carsten
Please review note 546516 and 935885. To read the weight values please see if creating a reference characteristic to table MAAPV will help. This table has data from material master. You can then add values of the characteristics that is a reference characteristic to MAAPV-BRGEW by using $SUM_PARTS. Please let me know if this does not help. I haven't tested it in our system but I can check and test in our system if it works.
Regards
Amber