Many SAP reports have direct download function to EXCEL.
SAP Query and SAP QuickViewer are excellent tools for Downloading (BvdR AO) the data.
SAP RFC functions can be called directly from Excel / VBA.
Use transaction BAPI in SAP to find your business object and study the function
For uploading the data into another SAP system use LSMW or BDC program. LSMW is the best tool for data uploading.
I have already done several system mergers, and we usually do not have the need to download data.
SAP can talk to SAP. with RFC and by using ALE/IDOC communication.
so it is possible to send e.g. material master with BD10 per IDOC from system A to system B.
you can define that the IDOC is collected, which means it is saved to a file on the application server of the receiving system.
you then can use LSMW and read this file with several hundred thousand of IDOCs as source.
Field mapping is easy if you use IDOC method for import, because then you have a 1:1 field mapping.
So you need only to focus on the few fields where the values changes from old to new system..
Thanks for your information.we are not using ALE/IDOC method in our current 4.7 system. so it will be very difficult to set up ALE/IDOC in old system(4.6c) also as we do not have access to that system directly.
Actually , we are sending some views to them for data downloading from 4.6 system. Once we got the data in excel, then we will do LSMW or BAPI or BDC to upload the data into 4.7 system. Is it ok? please advice.