What is SAP ALE IDocs? How does it work?
a purchase order can be sent as an IDOC using an OS file system to a VAN from SAP for a vendor to then retrieve and fill. When the vendor picks up the IDOC, the software used will post and acknowledgement the SAP system will then pickup and note that it was received by the vendor.
SAP ALE Idocs are electronic documents used for the exchange of information in an EDI format
Definitions
ALE stands for Application Linking and Embedding
IDOC stands for Intermediate Documents
EDI stands for Electronic Document Interchange
Normal IDOCs
An IDOC is a formatted document similar to EDIFACT, where individual fields of data are arranged in the single line of fixed delimited data, which means there is a starting position, a length, and an offset.
This can be a file that’s merely downloaded or submit to a VAN (value added network typically supporting the secure file transfer protocol, sFTP).
For example, a purchase order can be sent as an IDOC using an OS file system to a VAN from SAP for a vendor to then retrieve and fill. When the vendor picks up the IDOC, the software used will post and acknowledgement the SAP system will then pickup and note that it was received by the vendor.
ALE IDOC
With ALE IDOCs this process is different whereas the IDOC will be transmitted electronically, and encrypted, in memory through a TCP/IP protocol using an RFC Server which is maintained in SAP to manage the distribution of IDOCs to their destinations as defined (as destinations) in SAP.
In this case the subsystem (the system to receive the IDOC) will be registered through an RFC server to the sending SAP system, however, the RFC server will reside on the side of the receiving system. This communication is called a tRFC handshake, and it’s processing is an asynchronous process.
The ALE process allows a more streamlined and automated solution over that of legacy EDI, and one without files being tossed around. Additionally, this allows for instant transformation as part of that process so that middleware can directly receive and transform the IDOC into the format acceptable by the subsystem.
Due to its anyscronous nature, bottlenecks do not result in data loss when a subsystem is overloaded or incapable of receiving the full load during times of peak activity because only one IDOC at a time is transmitted to the registered RFC Server of a subsystem at a time and the RFC Server will only accept one IDOC at a time when registered through rRFC.
In a nutshell, the ALE prefix just means its an integration method that doesn’t require the existence of files or use of the file system. However note, ALE IDOCs are significantly more complex in configuration, setup, and maintenance than EDI/VAN solutions and a VAN can receive a bulk load of IDOCS at one time.
The tradeoff is speed and automation which ultimately equates to dollars. ALE IDOCS may cost more initially, but the ROI is quickly realized over EDI and VAN’s.
The other major factor and difference is that VAN’s are operated by 3rd parties, which also costs money long term, whereas ALE allows direct communication between the sender and receiver making is a much better suited solution for modern day electronic document interchange.
I hope this helps. Good luck!