Transport Routes (Export/Import)

 Sure, let's break down the concept of Transport Routes (export/import) in SAP Basis with detailed notes.

Transport Routes (Export/Import) in SAP Basis

Transport routes are the core logical paths within SAP's Transport Management System (TMS) that define how changes (development objects, customizing data, and sometimes master data) flow from one SAP system to another within a transport domain. They ensure a structured, controlled, and traceable movement of these changes from development to quality assurance and finally to production.

The terms "export" and "import" refer to the two main phases of a transport request's journey:

• Export: The process of extracting the changes recorded in a transport request from the source SAP system (e.g., Development). This generates the data and cofile (control file) for the transport.
• Import: The process of applying these exported changes to the target SAP system (e.g., Quality, Production).

I. Key Components of Transport Routes

1. Transport Domain Controller (TDC): All transport routes are centrally defined and maintained on the TDC (e.g., your DEV system in client 000).
2. Systems: The individual SAP systems (DEV, QAS, PRD, etc.) that participate in the transport landscape. Each system must be part of the same transport domain.
3. Transport Layers:
   • Logical grouping mechanism for different types of changes.
   • Standard Transport Layer (e.g., ZDEVC, Y<SID>): Used for customer-specific developments (Workbench objects like ABAP programs, reports, function modules, data dictionary objects) and customizing changes that affect cross-client tables or need to be recorded explicitly.
   • SAP Layer: Predefined for SAP standard objects (usually for SAP repairs or upgrades, not custom development).
   • Customizing Layer (e.g., CUS, SAP_CUST): Often implicitly used for client-specific customizing (SCC4 settings) where changes are recorded directly in transport requests. This layer is usually associated with the consolidation route by default or explicitly defined.
   • No Transport Layer ($TMP): Objects saved in the $TMP (local) package are not transported.
4. Transport Group: A set of SAP systems that share the same underlying transport directory (/usr/sap/trans). All systems linked by a transport route must belong to the same transport group or have a defined transport path to it.

II. Types of Transport Routes

There are two primary types of transport routes, each serving a distinct purpose in the software development lifecycle:

1. Consolidation Route (Transport of Copies / Standard Transport):

   • Purpose: To move changes from a development system to a quality assurance (QA) system for testing. This is where development work is "consolidated" before delivery.
   • Direction: Unidirectional (e.g., DEV rightarrow QAS).
   • Trigger: When a transport request (TR) is "released" in the development system (transaction SE09/SE10). This triggers the export process.
   • Transport Layer Assignment: A transport layer is always assigned to a consolidation route. This layer dictates which type of changes will follow this route. For example, a ZDEVC layer assigned to a DEV rightarrow QAS consolidation route means all Workbench objects and selected customizing requests created under ZDEVC will follow this path.
   • Import Process: The released TR appears in the import queue of the target QA system and must be explicitly imported by a Basis administrator.
   • Example: You develop an ABAP report in DEV, save it under package ZFI_REPORTS, which belongs to transport layer ZDEVC. When you release the TR in SE10, it exports from DEV and appears in the QAS import queue via the DEV rightarrow QAS consolidation route for ZDEVC.

2. Delivery Route:

   • Purpose: To move tested and approved changes from a quality assurance system to a production system. Also used for transports between other systems (e.g., production rightarrow reporting system, production rightarrow hotfix system).
   • Direction: Unidirectional (e.g., QAS rightarrow PRD).
   • Trigger: After successful testing and approval in the source system (e.g., QAS), the transport is imported into the production system. This import can be triggered manually or via a configured QA approval procedure.
   • No Transport Layer Assignment: Delivery routes do not have a transport layer assigned directly. They transport whatever is released in the source system's import queue or is moved to a subsequent queue.
   • Example: After testing the ABAP report in QAS, you import the TR from QAS into PRD via the QAS rightarrow PRD delivery route.

III. Setting up Transport Routes in TMS (STMS)

All transport route configuration is performed on the Transport Domain Controller (TDC) in client 000.

1. Log on to the TDC: Access the SAP system designated as your Domain Controller (e.g., DEV), client 000, with an administrative user.

2. Start TMS Transaction (STMS):

   • In STMS, click on Overview -> Transport Routes. This opens the graphical editor for transport routes.

3. Layout Systems:

   • The left pane of the graphical editor shows all systems in your transport domain.
   • Drag and drop the system icons into the main editor area to arrange your landscape logically (e.g., DEV, QAS, PRD from left to right).

4. Create Transport Layers (if not already existing):

   • In the graphical editor menu, go to Edit -> Transport Layer -> Create.
   • Standard Customer Layer: Create a layer for your custom development.
     • Layer: ZDEVC (or Z<SID> or a meaningful name, usually starting with Z/Y).
     • Description: "Customer Development" or "Development Changes for <SID>".
     • Default: Set this as the default layer for recording changes if you want.
   • Save the layer.

5. Create Consolidation Routes:

   • Purpose: DEV rightarrow QAS (for Development System).
   • In the graphical editor, click the "Create Transport Route" icon (or go to Edit -> Transport Route -> Create).
   • Drag and drop a line from the source system (e.g., DEV) to the target system (e.g., QAS).
   • A dialog box "Create Transport Route" appears.
   • Route Type: Select "Consolidation Route".
   • Transport Layer: Choose the relevant transport layer (e.g., ZDEVC) from the dropdown. This assigns the layer to this consolidation route.
   • Description: Provide a meaningful description (e.g., "DEV to QAS Consolidation for ZDEVC").
   • Click "Continue" and "Save".
   • Result: When objects belonging to this transport layer are released in DEV, they will be exported and placed in the import queue of QAS.

6. Create Delivery Routes:

   • Purpose: QAS rightarrow PRD (for Production System).
   • In the graphical editor, click the "Create Transport Route" icon again.
   • Drag and drop a line from the source system (e.g., QAS) to the target system (e.g., PRD).
   • A dialog box "Create Transport Route" appears.
   • Route Type: Select "Delivery Route".
   • No Transport Layer: Notice that there is no option to assign a transport layer for delivery routes, as they simply "deliver" whatever is in the source system's import queue.
   • Description: Provide a meaningful description (e.g., "QAS to PRD Delivery").
   • Click "Continue" and "Save".
   • Result: After changes are successfully tested and imported into QAS, they can then be imported into PRD via this delivery route.

7. Activate and Distribute Configuration:

   • After you have created all your desired transport layers and routes:
   • Click the "Save" icon in the graphical editor toolbar.
   • Then, click the "Activate and Distribute" icon (or Configuration -> Distribute and Activate).
   • This crucial step distributes the updated TMS configuration (including the new transport routes) to all systems in the transport domain. This ensures all systems are aware of the defined paths.

IV. Transport Process Flow (Export/Import)

Let's illustrate the typical flow for a change from development to production:

1. Development (DEV) - Export Phase:

   • A developer creates or modifies an object (e.g., ABAP program, customizing setting).
   • The change is recorded in a Transport Request (TR) (transaction SE09/SE10).
   • The object's package is assigned to a Transport Layer (e.g., ZDEVC).
   • When the TR is released in SE09/SE10, the tp program exports the object's data from DEV.
   • The exported data and control files are placed in the shared usr/sap/trans/data and usr/sap/trans/cofiles directories.
   • The TR then appears in the Import Queue of the Quality Assurance (QAS) system, as defined by the DEV rightarrow QAS consolidation route for ZDEVC.

2. Quality Assurance (QAS) - Import and Test Phase:

   • A Basis administrator (or automated process) uses STMS_IMPORT on the QAS system to view its import queue.
   • The TR from DEV is selected and imported into QAS.
   • After successful import, functional consultants and testers perform comprehensive tests on the new functionality/changes in QAS.
   • If a QA Approval Procedure is configured (highly recommended for production transports), the TR must be formally approved in QAS before it can proceed to production.

3. Production (PRD) - Import Phase:

   • Once the TR is thoroughly tested and approved in QAS, it appears in the Import Queue of the Production (PRD) system, via the QAS rightarrow PRD delivery route.
   • A Basis administrator (or automated process, often scheduled during a maintenance window) imports the TR into PRD using STMS_IMPORT.
   • Post-import steps (e.g., checking import logs, functional verification) are performed.

V. Advanced Transport Route Concepts

• Target Groups: Instead of creating multiple delivery routes to identical production systems (e.g., multiple PRD clients or parallel PRD systems), you can group them into a "target group." A single route points to the target group, and the transport is imported into all systems within that group.
• Virtual Systems: Used for systems that are not actual SAP instances but serve as placeholders in a complex landscape (e.g., a "development in progress" branch).
• Extended Transport Control (CTC): A tp parameter (CTC = 1 in development system's tp parameters) that enables more complex transport routes, such as:
  • Cascading Systems: Where a system imports a transport and then automatically pushes it to another system's import queue.
  • Mass Transports: Transporting multiple transport requests in a specific order.
• Retrofit: A complex scenario (often using Solution Manager's ChaRM) for managing parallel development streams (e.g., project development vs. urgent bug fixes in production) and synchronizing changes.

VI. tp and Transport Route Interaction

While you configure transport routes visually in STMS, the actual work is performed by the tp program using its profile parameters.

• tp determines the target system for an export based on the transport layer of the object being transported and the configured consolidation route.
• During an import, tp reads the buffer file (which contains the import queue) for the specific target system and processes the data and control files from usr/sap/trans.

Properly configured transport routes are fundamental to a stable and manageable SAP landscape, ensuring that changes are moved efficiently, securely, and with full traceability.