The Transport Expresso server software must also be installed in each of the SAP systems that will have transports controlled by Transport Expresso.
When necessary, the server software running in the Transport Expresso domain controller connects to each of the participating SAP systems via remote function call. This might be necessary to gather transport request information, release transport requests or to perform import actions.
It is not necessary for any participating SAP system to share transport directories with any of the other SAP systems in the Transport Expresso system landscape. If transport files are missing, the Transport Expresso domain controller automatically requests the transport files, on demand, from the source SAP system and forwards them to the SAP system that the changes are to be imported into.
The only requirement is that the Transport Expresso domain controller must be able to connect to each of the participating SAP systems via the remote function call (RFC) protocol.
: Multiple Development Streams with Separate Transport Directories
Transport Expresso can support a system landscape with three development streams (such as ERP, CRM and BW), where each development stream has its own transport directories. That is, the development, test, production (etc.) ERP systems share a common set of transport directories, however these transport directories are not shared with any of the CRM or BW systems.
In this example, the ERP development system might be acting as the Transport Expresso domain controller for all three development streams, even though none of the SAP systems in the ERP stream share transport directories with either the CRM or BW systems (and vice versa).
: Single Development Stream with Multiple Transport Directories
Transport Expresso also supports a system landscape where the SAP systems of a single development stream do not share the same set of transport directories. It might be that the development and test systems share a common set of transport directories, but for security reasons, the production system has its own set of transport directories.