Serialization by Message Type
The ALE function module SERIALIZATION_CHECK flags each IDoc that has been overtaken. An overtaken IDoc is defined as follows: assuming IDocs A and B contain information about object/document X (such as order number 4711). If A is created by the SAP sending system before B, but B has already been successfully processed by the SAP receiving system, A is said to have been overtaken.
Process
To use serialization you need to:
Define the serialization object for your message type - ALE extracts the object/document number from the IDoc’s data segments, and hence needs to know which field to use.
Call the function module Serialization_Check at the beginning of your inbound function module.
Handle overtaken IDocs according to your needs.
Ensure that the inbound function module’s export table SERIALIZATION_INFO contains the serialization table from the function module SERIALIZATION_CHECK (see the example below).
Example
The Example Program for Serialization shows the additional coding necessary in the function module IDOC_INPUT_XAMPLE to recognize overtaken IDocs and to return an appropriate error message. The example assumes that overtaken IDocs need to be manually dealt with, that is, they cannot be automatically processed.