Message Services 
You use this component to keep a copy of data that is sent to and from your plant systems, which allows plant operations data to be independent of the ERP system.
Message services allow you to do the following:
Enable communication between systems
Transfer data using IDocs, synchronous and asynchronous remote function calls (RFC)
Provides Quality of Service (QoS) support
Exactly Once (EO) for all message types like RFC, IDoc, and HTTP
Exactly Once in Order (EOIO) for HTTP messages
You can use the Message Services actions in the SAP Manufacturing Integration and Intelligence (SAP MII) Workbench. For more information, see Message Services.
Message Services includes the following screens: