Both ALE technology and synchronous RFCs are used for transferring data between the external planning system and R/3. Depending on the scope of the integration, both ALE and synchronous RFC, or ALE alone, are used.

The transfer of master data to the external system is triggered through an on-line ALE transaction or a background job that uses the transaction programs. Change pointers, which link the changed document to ALE master data outbound transactions, are used to transfer data which has been changed since the last data transaction. Typically, change pointers are activated after the initial data transfer so that data traffic is reduced. An alternative approach is to retrieve master data through a request IDoc, which can be used in conjunction with the transaction programs to guarantee the accuracy of the master data in the external system.

Both demand history and transaction data in the stock/requirements list are transferred in the same fashion as master data. No change pointers are designed for them. However, there are several options available for sending out new demand history, or a stock/requirements list for materials that have new MRP transaction data.

To upload planning results for a manufacturing plant, the interface uses inbound ALE IDocs that pass data into R/3’s Sales and Operational Planning (SOP). To post planning results or a deployment plan for distribution centers, the interface creates either stock transport orders by using ALE, or requisitions by using synchronous RFC. The interface also provides an RFC function module to delete unwanted requisitions.

Both ALE and Synchronous RFC use the SAP remote function call (RFC) interface. In the documents "SAP Remote Function Call (RFC) Interface" and "ALE Interface", you will find detailed information on the requirements a subsystem or an integrator must fulfill if it is to link up to R/3 and use the DRP interface.