Interface program in file concept

Question

Hi,
    please help me in solving this interface. Iam new to this area , please hel me.
1) Select all the entries from the ZSWAPHISTORY table where the ‘ApproveDate” = SY-DATUM.
     The data should be selected on the basis that the entries that are changed from the previous run of the interface and they have been approved.
Create an Internal table with all the required fields to hold the data from ZSWAPHISTORY.
Create another internal table of the same structure as above to get all the necessary entries after conversions to create the file.
     The SwapFromCust and SwapToCust fields have to be converted before sending them to the file
     And this conversion depends on the OSC field.
          IF OSC = RTA
               Then customer number = DA+ SwapFromCust /      SwapToCust
          ELSEIF OSC = RTE
               Customer number = EA+ SwapFromCust / SwapToCust
Note: Please refer the FD for the table and fields of ZSWAPHISTORY. (An Excel sheet as an attachment with the name ZSwapHistory Table Layout).
2) The interface has to check to which business code (EA or DA) the file have to be send, that is based on the Sales Organization.
     IF ZSWAPHISTORY-OSC = RTA.
          Then business code = EA
     IF ZSWAPHISTORY-OSC = RTE.
          Then business code = DA
     This field comes under the name sales company code.
3) Using the final internal table create the file with the name “InvSwapHistory_IF” and save it at the given directory.
Use the Front _End Services Methods to create the file.
Pass the file name InvSwapHistory_IF and the internal table to the methods.
Create the file and save it to the Application Server,
          Open dataset (P_file) for output.
          Loop the final internal table
          Write the header with all the fields to the file
          Write the all entries into the file
          Close in the data set.
Please help me
Thanks
Ali

Answer 1

Ashish,
From the link,
http://help.sap.com/saphelp_nw04/helpdata/en/43/d92e428819da2ce10000000a1550b0/content.htm
<i>Every step of an integration process uses Integration Server resources.
&#9679;      Every message that is sent to the Process Engine is duplicated.
&#9679;      Every message that is sent from the Process Engine is duplicated.
&#9679;      A work item is created for the process itself and for every step the process contains.
This means that for a process that just receives one message that is sent without being processed further, four messages and three work items are created.
For this reason, you must ensure that you take Integration Server resources into account when you define integration processes. </i>
So, by having the transformation outside the BPM , you are avoiding one message to be stored inside your BPM and therby the replication. The message that hits the BPM is the transformed message directly which avoid consumption of resources.
So, as much as possible keep mappings outside the BPM.
Regards,
Bhavesh