EDI Gapping/mapping

Gapping/mapping - This process is done when your client wants to send some application document (can be sales order confirmation, Purchase order, Invoice) to it's customer (or vendor). For for discussion purpose, lets say your client needs to send billing document to a customer. So one way is print it on invoice format and send it via mail or Faxing the printout or emailing it. or finally sending it via EDI.

EDI is the data exchange medium, which is going to send the data relevant for billing to the customer. Standard 810 EDI is used for invoice transaction. SAP billing document creates a IDOC which is triggered from a message type (output type at billing header level).

An IDOC contains Data records, which contain billing document data. Now not all the data on this IDOC is required to be sent to customer, only certain fields are enough to tell the customer about the bill - fields like Payer #, payment terms, Customers PO #, SO#, delivery #, line #, Material #, Net value # and overall billing document value. But on IDOC we have much more data available then this.

Now on EDI mapping we will sit with an EDI contact, and map what fields on IDOC means and where it can be put on EDI segments. Like
idoc field name EDI Field name
Purchase order # E1EDK02-BELNR BIG04
Invoice # E1EDK02-BELNR BIG02
Payer E1EDKA1-PARTN N104
Payment terms E1EDK18-PRZNT ITD01
Material E1EDP19-MATNR IT101

Like this you will have to map all the fields on a excel spreadsheet so EDI can have logic in their subsystem to send the invoice to customer successfully.