Transport Management System (TMS)

Whenever we make changes to the data or to the repository objects in a SAP system, SAP creates a transport request for the same so that the changes that have been made in one of the systems can be moved to other systems as well. When the client that we are working on is a test client it can be configured to not allow any transport to be exported to another system. Such type of change requests are called local change requests and non transportable. On the other hand if we are working on a production client we can configure the client settings as not modifiable so that it doesnt allow any changes to be made in that client. Now if a client is set to accept changes and create a corresponding transport request for any change then in such a client we can make changes. Changes to the SAP system can be of two types:

1) Customizing Change (CUST)

2) Development Change (SYST)

Customizing changes are those which donot alter the structure of the repository objects (like tables etc). They are simple changes like addition of a new row in a table. The implementation guide (Transaction SPRO) is where most of the Customizing changes are done. Customizing change request are called CUST.

Development changes are those that alter the structure of the repository objects. For example addition of a new column in an existing table or creation of a new object. Workbench change request are called SYST.

The changes that are made flow in a particular manner inside a landscape. Changes from Development are imported to the Quality where they are tested and once the quality assurance procedure is completed they are imported into the Production environment.

The control information for carrying out the transport as well as the data that needs to be transported is stored at the OS level in the \\$SAPTRANSHOST\sapmnt\trans directory for windows OS. SAPTRANSHOST is the name of the server. The process of releasing a transport request is called export and the process of accepting the changes by other systems is called import.

This directory is called the transport directory and is shared by all the systems in a landscape. Such systems that share a common transport directory are called a transport group. Mostly there is only one landscape per SAP implementation but in some cases there can be several landsapes and thus several transport groups can exist. All transport groups that are in the same environment constitute a transport domain. Every transport group in a domain has its own transport directory and if a transport has to be made between two systems that are in different groups then it has to be done manually.

The TMS configuration settings in a transport domain rest with one of the system known as the domain controller. Any system with high availability can be made a domain controller. The domain controller has all the configurations settings like the transport routes and the transport layers etc and it distributes them to the other systems in the domain through Remote Function Calls.

 TMS can be configured by logging in client 000 with SAP* user. When we login for the first time the system searches for an existing transport domain and its domain controller. This information is present in the files present in subdirectory bin of the trans directory. If no information is found the system creates a new transport domain and creates the existing system as its domain controller otherwise it sends a request to the domain controller for inclusion in the domain.