Bol Programming in TPM

Hi,

I have written a below code in order to create line item/Products for a TPM.

IF lr_core IS BOUND.

   TRY.

       CALL METHOD lr_core->get_root_entity

         EXPORTING

           iv_object_name = 'Trade'

           iv_object_guid = lv_cgpl_guid

         RECEIVING

           rv_result      = ent.

       IF ent IS BOUND.

         LOOP AT lt_itab INTO ls_itab.

           SELECT SINGLE product_guid FROM comm_product INTO lv_prod_guid WHERE product_id = ls_itab-lv_prod.

           IF lv_prod_guid IS NOT INITIAL.

             ent_prod = ent->create_related_entity( iv_relation_name = 'TPMProductRel').

             CALL METHOD ent_prod->if_bol_bo_property_access~set_property

               EXPORTING

                 iv_attr_name = 'PRODUCT_GUID'

                 iv_value     = lv_prod_guid.

             CALL METHOD ent_prod->if_bol_bo_property_access~set_property

               EXPORTING

                 iv_attr_name = 'PRODUCT_ID'

                 iv_value     = ls_itab-lv_prod.

             CALL METHOD ent_prod->if_bol_bo_property_access~set_property

               EXPORTING

                 iv_attr_name = 'QUANTITY'

                 iv_value     = ls_itab-lv_quant.

             lr_core->modify( ).

             lr_transaction = lr_core->get_transaction( ).

             lv_success = lr_transaction->save( ).

             IF lv_success EQ abap_true.

               lr_transaction->commit( ).

             ENDIF.

           ENDIF.

         ENDLOOP.

       ENDIF.

The code gets executed successfully but no line item gets added up.

Could anyone please suggest what I am missing or any other way to execute it.

Thanks and Regards,

Ashish Singh.