BAPI for Creating External Operation with Service Line

Hi SAP Gurus,

I have a requirement of Create a Work Order of External Operation with Service Line by using BAPI ,For that I am using a BAPI_ALM_ORDER_MAINTAIN with following test data

IT_METHODS

REFNUMBER OBJECTTYPE METHOD OBJECTKEY

1                     HEADER         CREATE   %00000000001

1                     OPERATION    CREATE   %00000000001

1                      SAVE

IT_HEADER

ORDERID       ORDER_TYPE PLANPLANT MN_WK_CTR PLANT PLANGROUP  EQUIPMENT  START_DATE PRIORITY  SHORT_TEXT

%00000000001  ZM01               US05             PM00000         US05    ELE               10026344         27.07.2015        3               DEMO WORK ORDER

IT_OPERATION

ACTIVITY       CONTROL_KEY   WORK_CNTR  PLANT     DESCRIPTION     PURCH_ORG     PUR_GROUP  MATL_GROUP

0020                    PM03                PM00000         US05  DEMO OPERATIONS   USP1                 204                    AMINOACID

IT_SERVICEOUTLINE

ACTIVITY      OUTLINE           SHORT_TEXT                  FROM_LINE       

0020               0000000001          DEMO SERVICE LINE       1

IT_SERVICELINES

ACTIVITY     OUTLINE         SRV_LINE      SHORT_TEXT                   QUANTITY     UOM

0020              0000000001     0000000010      DEMO SERVICE LINE        1                    AU

Whenever i am executing the BAPI_ALM_ORDER_MAINTAIN with above test data along with BAPI_TRANSACTION_COMMIT, the work order is created without  service line (0010)  of external operation (0020), I tried several times but without luck, Please help

Help would be appreciated

Thanks

Sumit