Onhand Quantity On a Given Date

Recentlry i have worked on one report, The main purpose of the report is , based on item, oraganizarion and subiventory it need to display the onhand qty for a gievn date. i used below code in formula column of report to calculate onhand qty on a given perticular date.

FUNCTION CF_LAST_BALFormula RETURN NUMBER IS
   v_onhand_qty   NUMBER;
   v_last_qty     NUMBER;
   v_target_qty   NUMBER;
BEGIN
   SELECT SUM(transaction_quantity)
   INTO   v_onhand_qty
   FROM   mtl_onhand_quantities_detail
   WHERE  inventory_item_id = :inventory_item_id
   AND    organization_id   = :organization_id
   AND    subinventory_code = :Subinventory;
  
   SELECT NVL(SUM(Transaction_quantity),0)
   INTO   v_last_qty
   FROM   mtl_material_transactions
   WHERE  inventory_item_id = :inventory_item_id
   AND    organization_id   = :organization_id
   AND    subinventory_code = :Subinventory
   AND trunc(NVL(transaction_date,creation_date))>= TRUNC(TO_DATE(:p_last_date,'RRRR/MM/DD'));

      v_target_qty:=(v_onhand_qty)-(v_last_qty);

   RETURN(v_target_qty);
EXCEPTION
   WHEN OTHERS THEN
      RETURN 0;
END;