SAP Basis Change and Transport System Pre Requirements

To set up your system landscape:
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Install an R/3 System as a development system; the quality assurance and production R/3 Systems are not required at this stage. Create a transport directory at operating system level. This directory is required for the Transport Management System.If you have performed a database copy, initialize the Change and Transport Organizer (CTO) using Transaction SE06.Configure the system landscape using the Transport Management System (TMS) using Transaction STMS.

Transporting enables you to synchronize Customizing and development in multiple R/3 Systems through the transfer of changes from the development system to downstream systems. Transports along the transport route must occur in only one direction.Transporting requires a transport directory to enable R/3 Systems in the system landscape to store and access various data files, command files, and log files.Physically, changed objects in a three-system landscape are transported in three steps: 
All objects in a change request that is to be released are exported – by being "copied" – from the database of the source system to the transport directory.

The objects are imported into the database of the quality assurance system. After testing and verification, the objects can be imported to the defined delivery systems.

Creating Trasport Directory

The global transport directory and all the necessary subdirectories are created during the installation of an R/3 System. Mount this directory using the operating system tools (nfs for UNIX; share for NT) for all systems within a system landscape or a transport group. The amount of disk space required depends on the amount of development work: estimate 10 MB for each customizer and developer. You will need additional space for client exports. The R/3 Parameter DIR_TRANS has to point to the path of the transport directory. For Unix, the default path is /usr/sap/trans. For Windows NT, the default path is \\$(SAPTRANSHOST)\sapmnt\trans and you must define the transport host with the alias SAPTRANSHOST on the domain name server.

The subdirectories required in the common transport directory include: 

Ÿ bin: Configuration files for tp (TP_.PFL) and TMS (DOMAIN.CFG)
Ÿ data: Exported data
Ÿ olddata: Old exported data (to be archived or deleted)
Ÿ log: Transport logs, trace files, and statistics
Ÿ actlog: Action logs for all tasks and requests
Ÿ buffer: Transport buffer for the each system, indicating which transports are to be imported
Ÿ cofiles: Command or change request infrmation files that include information on the transport type, object classes, required import steps, and post-processing exit codes Ÿ sapnames: Information pertaining to transport requests for each SAP user Ÿ EPS: Download directory for advanced corrections and Support Packages
Ÿ tmp: Temporary data and log files

The Transport Management System (Transaction STMS) enables you to:

Ÿ Define an R/3 System's role within a system landscape or transport domain Ÿ Configure the transport routes using either a graphical editor or hierarchical editor Ÿ Configure the transport tool transport control program tp.Display the import queues of all R/3 Systems in the transport domain Ÿ Decide whether the quality assurance testing was successful in the QA System Ÿ Start the import of change requests in an import queue Ÿ Perform transports between R/3 Systems without a common transport directory Ÿ Handle transport proposals of developers

System Landscpae

With R/3 Release 4.0, SAP introduced the TMS and the concept of a transport domain (all R/3 Systems to be managed centrally using the TMS) and a transport group (all R/3 Systems that share the same transport directory and belong to the same transport domain).The term system landscape refers to the group of R/3 Systems normally comprising the development system, the quality assurance system, and the production system. A system landscape consists of all the R/3 Systems that share change requests for the purpose of maintaining consistent Customizing and development environments.A system landscape is usually synonymous with a transport domain. Having all R/3 Systems of the same system landscape in the same transport domain ensures consistent configuration and easy delivery of all change requests.

A transport domain may, however, contain more than one system landscape. For example, a company may have different system landscapes for each subsidiary. These R/3 implementations are very different and do not share change requests. To benefit from centralized configuration with the TMS, you can include both system landscapes in the same transport domain. 

Strecture of TMS

The TMS supports several transport directories within a transport domain. The R/3 Systems with a common transport directory each form a transport group.Transports between different transport groups are supported by the TMS; transports between different transport domains are only supported by external systems.In most implementations of R/3, a customer only needs one transport domain and one transport group. If more than one transport directory is needed, additional transport groups are required.All R/3 Systems to be administered using the TMS belong to a transport domain. Within this transport domain, certain system settings such as the transport route settings are identical for all R/3 Systems. In order to have consistent settings, in the transport domain, one R/3 System (the domain controller) has the reference configuration, and all the other R/3 Systems in the transport domain receive copies of this reference configuration.

When setting up an R/3 System with the TMS, you include the R/3 System in an existing or new transport domain. All R/3 Systems in a transport domain must have unique system IDs, and may or may not share the
same transport directory.Within a transport domain, the TMS enables RFC communication between all R/3 Systems, for example, to distribute configuration changes or perform imports.Changes to the transport domain configuration are made in the domain controller, and then distributed to all R/3 Systems in the transport domain. Each time you make a change to the domain controller, a dialog box is displayed asking whether to distribute the change. You can distribute several changes at one time.

Setting up TMS

Before you can work with the TMS, you must configure the TMS on all R/3 Systems in your system landscape.To configure the TMS:

ŸConfigure the transport domain
 
Assign R/3 Systems to the transport domain, and specify one R/3 System as the transport domain controller.
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Configure transport routes 

The transport routes are used to define both the target system in which you want to consolidate change requests, and the R/3 Systems to which change requests are delivered after verification and testing.

ŸConfigure Quality Assurance (QA) Procedure
 
Define a QA system, where the decision is made whether objects may be further transported to the production system.After setting up the TMS, use the TMS tools to check and monitor TMS configuration. The transport domain and transport groups define which R/3 Systems are managed by the TMS and which systems share the same transport directory. Transport routes define how change requests are transported and thus strictly reflect the system landscape implementation process.

The transport domain contains all R/3 Systems whose transports are to be administrated jointly. One of these R/3 Systems is chosen as the transport domain controller. Since all activities relevant to the entire transport domain, such as configuring transport routes or RFC connections, can only be carried out on the domain controller, the R/3 System selected to be the domain controller should have:

ŸHigh availability
ŸA high level of security
ŸA high level of maintenance
 
The domain controller is normally configured on a production system or a quality assurance system.The system load on the R/3 System that is chosen as the domain controller is low, and only increases for a short period when the TMS configuration is changed.