Client Control 
Client Control
You can use the Transport Organizer to record all changes to Customizing settings in change requests and mark them for transport.
The transport of Customizing settings to another SAP System is prepared. You only need to release the change request.
However, it is not always a good idea to record every single change made to the system. That is why many SAP Systems have a test, training, or demo client in addition to the production client. Recording changes is not appropriate here. In extreme cases, this could even result in unintentional transports that could destroy the target client.
To meet these sometimes contradictory requirements, you can assign each client appropriate attributes, which you can maintain in table T000 (transaction SM30):
The setting selected for a client applies only to changes to its client-specific Customizing settings, not to client-independent settings. The changes made to client-independent Customizing settings are recorded together with the changes to Repository objects and do not require a client-specific entry in table T000.
In a production client, client control does not influence the current settings (Customizing activities that can be accessed directly from the application menu). You can always change these settings in a production client; they are not recorded in Customizing requests.
Different request types in the Transport Organizer allow you to distinguish between the two modes. Changes to cross-client Customizing objects and to Repository objects are recorded in Workbench requests; changes to client-specific Customizing objects are recorded in Customizing requests.
If you use only Customizing requests, you make sure that the results of a Customizing project can be transported to the target client of another system without affecting other clients there.
In contrast, no guarantee can be given that the results of transporting Workbench requests will be restricted to one client. In this case, the import must be checked to establish whether it includes any cross-client objects. If such objects are found, we recommend that you adjust the corresponding settings in the source and target systems in order to assess the affect on all other clients.
Other features that affect the client are:
Only the users SAP* or DDIC are permitted to log on. Other regular users are warned with a corresponding message when they attempt to log on.
EarlyWatch). This function is only intended for exceptional cases, when, for example, the basis for an adjustment is needed after an upgrade has been performed. Every "normal" client must be updated by an SAP upgrade, since otherwise data resources from system and Customizing tables required for transactions may not be available. However, you can prevent clients that need to contain certain tables purely for backup purposes (backup clients) from being supplied with SAP upgrades that are not necessary or not wanted. To maintain this flag, you require the administration authorization for the Transport Organizer (authorization S_CTS_ADMIN).