EDI Segment: A Structural Item of The Electronic Transaction
EDI Segment is a structural part of any EDI message and is represented as a group of related data elements. Being an intermediate information unit, EDI segment usually contains one or more data elements. Segment starts with a three-character data identifier and ends with a segment terminator. To separate the data elements in a segment, data element separators are used. EDI segments can be mandatory or optional. The usage of segment and data elements separators can be agreed by the trading partners during discussion of trading partners’ agreement and conformance manuals. Segments (one or several) can be organized as a loop (unbounded and bounded) in a definite transaction set.
An example of segments in a purchase order document (EDIFACT standard): UNH, BGM, DTM, NAD, LIN, QTY,PRI, UNS, CNT, UNT. As we see, each segment is represented by a three-character code describing data element types. Normally, the segment is ended by a segment terminator (usually the apostrophe (‘)).
EDI standards define the following basics for each type of electronic transaction:
- Segments that may be included in a document and their position – mandatory, optional and/or conditional
- Elements that may be included in a segment – each element corresponds every piece of information in EDI transaction
- The sequence of segments and elements in each document
- The number of times the definite segment can be repeated
After all the segments are collected in a definite sequence they compose a transaction set (an electronic document). After this a transaction set must be prepared for the further transmission in a form of an envelope.