Electronic Data Interchange For Administration, Commerce and Transport


EDIFACT, defined and maintained by bodies of the United Nations (UN) is used to standardize the electronic exchange of commercial documents and business news. Through the responsibitity of the UN, EDIFACT is often referred to as UN/EDIFACT.

All EDIFACT messages are based on the ISO9735, in which the syntax units are described in detail. So you will find the structure of the control segments (eg, UNH, UNT, etc.) described because they are considered standard across all messages.

The structure of an EDIFACT message looks under the above mentioned ISO standard as follows:

         Service String Advice     UNA  Conditional
  +----- Interchange Header        UNB  Mandatory
  | +--- Functional Group Header   UNG  Conditional
  | | +- Message Header            UNH  Mandatory
  | | |  User Data Segments             As required
  | | +- Message Trailer           UNT  Mandatory
  | +--- Functional Group Trailer  UNE  Conditional
  +----- Interchange Trailer       UNZ  Mandatory

(this graphic is in the ISO9735 document)


In the standard document issued by the UN rules are defined by which the individual EDIFACT messages are designed. These rules also describe the structure and form of the contents of each message. Due to the well-defined structures of the messages and their contents is the exchange of such information across different computer systems easier than through the use of proprietary data formats. The EDIFACT standards are named according to their year of publication.

Converter software

When converting from EDIFACT messages into the respective set of application system usable format (and backward), a so-called converter is used. This computer program uses the incoming EDIFACT messages to convert them into the format used by the application software. Depending on the development status of the converter it may also be responsible for coordinating the reception of messages or the transmission of the messages. About which way the data is sent from the sender to the receiver is not defined - all types of transmissions, ie email, FTP or other protocols or mailbox systems, can be used for the transport of EDIFACT messages.

For outgoing EDIFACT messages the converter uses the interfaces provided by the application system and converts the data which are available there in the EDIFACT format.
Here too, it depends on the efficiency of the converter in which way the own data needs to be prepared first before the converter can read them. Depending on the configuration level, it starts by creating FLF-files (Fixed-Length-Format) which that can be read by the converter. There may be converter too which are reading the data directly from the (SQL-) databases, which is quite efficient.