Updating the Central Repository 
Use
If a system has already been registered with the central repository, then you can update the central repository on demand. It is sensible to do this if:
Procedure
The transaction checks to see if there is currently a suitable background job in the state scheduled, released, or running. If there is not, the transaction schedules a job to update the central repository, after first asking you for job start conditions. The job is called CCMS_REPOSITORY_RECONCILIATION. The job reports changes made to the local repository only since its last report to the central repository. Job run times are therefore usually less than 30 seconds.
When the job has finished, the central and local repositories are updated. The transaction does not wait for this event.
See also:
Updating the Local Repository