Hi, try with something like this. Regards.
LOOP SOURCE_PACKAGE ASSIGNING <SOURCE_FIELDS>.
CLEAR: LV_QTY.
SELECT SUM( INV_QTY)
INTO LV_QTY.
FROM /BIC/ODS1 " **ODS SOURCE**
WHERE COMPANY EQ <SOURCE_FIELDS>-COMPANY AND
CALDAY LE <SOURCE_FIELDS>-CALDAY.
<SOURCE_FIELDS>-INV_QTY = <SOURCE_FIELDS>-INV_QTY + LV_QTY.
ENLOOP.