All development projects developed in the same SAP System and transported on the same transport routes are grouped together to form a transport layer.
Before you start the first development project, you create a transport layer in the TMS transport route editor. This transport layer is assigned to the development system as its standard transport layer. Objects delivered by SAP belong to the transport layer "SAP". Other transport layers are generally only needed when new development systems are included in the system group.
After you have set up the transport layer you set up the transport routes. There are two types of transport routes. First you set up consolidation routes, and then you set up delivery routes:
To make your changes transportable, set up a consolidation route for each transport layer. Specify your development system as the starting point (source) of these consolidation routes. Specify the quality assurance system as the transport target (in a two-system landscape, specify the production system as the transport target).
Any modified objects that have a consolidation route set up for their transport layer are included in transportable change requests. After the request has been released the objects can be imported into the consolidation system.
If you make changes to objects which have no consolidation route defined for their transport layer, then the changes are made automatically in local change requests (or in Customizing requests without a transport target). You cannot transport them into other SAP Systems.
You can set up one consolidation route only for each SAP System and transport layer.
When you define consolidation routes, note the additional functions available when you use Extended Transport Control.
After you have imported your development work into the quality assurance system, you then want to transport it into your production system. You may even want to transport it into several SAP Systems (for example, additional training systems). To do this, you have to set up delivery routes.
Delivery routes have a source system and a target system.
When you set up a delivery route, you are making sure that all change requests that are imported into the route's source system are automatically flagged for import into the route's target system.
You can set up several delivery routes with the same source system and different target systems (parallel forwarding). You can also set up delivery routes in sequence (multilevel forwarding).
CTS transport control makes sure that all requests from the development system are flagged for import into all other SAP Systems in the same order in which they were exported. This is important, since different requests can contain the same Repository object or the same Customizing setting at different development levels, and you must avoid overwriting a more recent version with an older version.
Here you can activate multiple delivery routes in sequence. You can choose any SAP Systems in the system group as the source systems of the delivery routes; they do not have to be consolidation systems. This allows you to implement complex chains of transport routes.
Multilevel delivery is not required in a two- or three-system group. In more complex system landscapes, particularly in layered development projects that have each other as sources, multilevel delivery may prove to be a suitable solution:
If there are SAP Systems in the system group with releases prior to 4.0, you can only use multilevel delivery under particular conditions. The Transport Management System checks these conditions when you set up the transport routes in a mixed system group.