Compares Customizing objects in two logical systems with transaction SCU0.
(clients in either the same R/3 System or different ones).

To compare objects, start the Customizing Cross-System Viewer in the logon client 
(client of the system in which you are logged on) and then logon in the compare client 
(client to be compared).

The Customizing Cross-System Viewer compares Customizing objects by the following criteria:

- Project IMG
  This option shows changes in your project.

- Application components
  This option compares Customizing objects in specified application areas.

- Business Configuration Sets
  This option concentrates on Customizing settings which are of particular importance for 
  the processes in your company. 

- Transport requests
  This option shows the objects which would be overwritten by a transport.

- Manual selection
  In this option, you specify which objects are compared.
 

The compare client security level must be:

0 (unrestricted), or 
1 (no overwriting)

You can set this in the client maintenance SCC4.

You must also create a Remote Function Call link in SM59.
 

Best regards,
SAP Basis, ABAP Programming and Other IMG Stuff
http://www.sap-img.com