A client is a self-contained unit in commercial, organizational, and technical terms. It has its own user master data and set of table key ranges.
The data of different clients is separated both in the database and at the kernel level: Open SQL statements executed by an SAP application use the client number in the WHERE clause. A table may contain data from several different clients, however the WHERE clause limits access to particular clients.
Client-specific data types are as follows:
- User master data, such as parameters and user groups.
- Customizing data, such as organizational units, assignments, and document types.
- Application data, such as business transaction data and material master data.
The SAP client concept can integrate several companies or subsidiaries in a single client. It does so using the following methods:
- Company Codes
Company codes define the smallest corporate organizational units, for which a complete self-contained set of accounts can be drawn up for external reporting.
- SAP Authorization Concept
The SAP authorization concept enables the parent company to access all subsidiaries for report purposes, while subsidiary-specific data is protected against access from other subsidiaries through company code definition.
Standard client roles fulfill the optimal minimum requirements of your SAP system.
The standard clients are as follows:
Client CUST: Development and Customizing
The central customizing client, where complete adaptation of the SAP system to customer-specific needs takes place. All changes performed in this client are recorded so that they can be supplied to other clients using the Transport Management System (TMS).
Client QTST: Quality Assurance
Used to test and verify the new customizing settings in the application.
Client PROD: Production
The client for production activities, that is, where your company's business is carried out. Customizing changes that are imported into this client have to first be tested carefully in the QTST client. This ensures that production operation is free of disruption.
To realize the full benefits of a multi-system landscape, every critical client should be located in a separate SAP system.
Note
The (logical) roles shown here are not identical to the (technical) client roles that can be chosen in transaction SCC4 (Client Maintenance). For example, the (logical) role QTST correspondents to the (technical) role Test. The (technical) client roles that can be selected in transaction SCC4 are Customizing, Test, Production, Demo, Training/Education and SAP Reference.
Additional clients within an SAP system landscape may include:
Client PREP: Pre-Production
Client for the final integration and validation test, located on a separate pre-production system: The pre-production system is the environment for the final integration test once the scope of the release has been fixed (release test), for regression test, technical system test including performance test and volume test and user acceptance test. Furthermore, production support changes are tested here (particularly while the QTST client is being used for integration testing of a new development release).
Note
The pre-production environment typically is owned by the production support organization.
Caution
The pre-production system must not be "corrupted" with new release functionality or new Support Packages until the appropriate time (ideally as close to Go Live as possible).
All pre-production systems should be regularly refreshed from the production system, if possible.
The overall setup of all pre-production systems should mimic the production as closely as possible, including hardware-architecture, to ensure that the testing performed is valid. In detail this means:
- Same high-availability and fail-over solutions
- Same hardware architecture, processor types and storage subsystem
- Same disk size and data volume (due to system copy)
- The number of additional application servers can be reduced and possibly enhanced on demand by means of virtualization (only needed when a full and exact simulation of the productive workload is possible).
- Client TRNM: Training Master
Client to build training sources and to act as source client for the client copy of the training execution client.
In this client, exercises and demos are prepared including sample data.
- Client TRNG: Training Execution
An end-user training environment. This client will be refreshed from the training master client. Training takes place here.
Client SAND: Sandbox
A sandbox client allows you to experiment with transaction data and configuration settings. This client contains application data.
Sandbox environments are made available for testing specific functionality and in particular system-wide or "non-removable" changes (such as the activation of Business Functions).
Caution
The transport of changes out of the sandbox should not be permitted. The sandbox is a purely standalone landscape with no connections to other environments. However, the sandbox may receive changes from the development in order to stay up-to-date.
- Client TEST: Unit Test
The goal of a unit test client is to verify customizing changes against sample data in a more stable environment. This can be done by copying customizing settings from the customizing client to the TEST client. This is called a unit test. In case that the test data has been destroyed during the tests, this client can be refreshed from the test data backup client (not included in this list).
- Client GOLD: Golden Client
The golden client is the "ultimate" reference client for all the good, complete and final configuration that is being used in the implementation. This client does not contain any application data, so you cannot perform any transactions here. This is a sensitive client and access needs to be restricted.
