The transport system moves data, objects, and customizations from one system to another system. Some general concepts about the transport system are:

• The purpose of a transport is to make changes in one system take effect in another system. Some examples of situations that would require a transport are:

• There are several types of transports. Some transports (such as those for company codes) can occur between clients within one system. Some transports (such as those for ABAP reports) are client-independent, and only occur between two systems.

• In order to preserve data consistency, transports should only occur between systems running the same R/3 version. Transporting between different R/3 versions is possible but should be scrutinized first (especially when changing table data that affects program behavior) to make sure that no unprediced side effects occur. Transporting data dictionary objects between different versions is usually OK if they are all custom objects.

• Before transports can be performed, the transport layers must be set up. Use transaction SE06 and read the related help files for setting up the transport layers.

• The tp command has several unconditional modes that are useful with troublesome transports (from The SAP R/3 Handbook):
  • 0. Import from buffer without deleting and then use unconditional mode 1 to allow another import into the correct location.
  • 1. During export, ignore the incorrect status of the transport control file. During import, execute the request even if it has already been imported.
  • 2. During import, overwrite original objects. During export, do not expand selection with TADIR brackets.
  • 3. During import, overwrite system-specific objects.
  • 4. Import into system other than the target system that was defined in the transport request.
  • 6. During import, overwrite objects that are unconfirmed repairs.
  • 8. During import, ignore transport restrictions based on table classes.
  • 9. Import into system even if it is locked against this type of transport.