Changes to master data objects are managed using the Shared Master Data (SMD) tool. The SMD tool distributes master data changes to the decentralized systems.

The SMD tool groups changes together according to their content and the time they were changed:

• Firstly, if several changes to a master data object have been made by different R/3 transactions and stored in different tables, they are combined into one single change to the master data object.
• Secondly, if several changes are made in close succession, they are also combined into a single change and distributed as one change.

The SMD tool is connected to the change document interface. If the master data changes are to be distributed, the application writes a change document. The contents of this are passed to the SMD tool. The tool writes change pointers, reads the application data and creates the master IDoc.

The master IDoc is then passed to the ALE layer, which sends it to all interested systems.