• An EDI document is comprised of an EDI Envelope, Segments and Data elements
• An EDI document can be pictured similar to a postal envelope that has address of the recipient outside and information inside
• While creating an EDI document, follow the mapping guidelines mandated by your trading partner according to the EDI standard they follow

An EDI document, or transaction, is made up or comprised of small pieces of information gathered into a standardized format. The standards for creating EDI transactions are developed and maintained by the American National Standards Institute, or ANSI and UN/EDIFACT Working Group (There are other standards as well, but most or all of the documents that you are likely to deal with are based upon the ANSI X12 or EDIFACT standards). It is advised that you adhere to the rules of the EDI standards you are being mandated by your trading partners

Once your documents are received by your trading partners, they will respond with an appropriate document with the same method.

1. EDI Envelope

Think of an EDI envelope as a paper envelope that you are sending to someone with some information inside. The front of an envelope has sender’s and receiver’s address and the back is closed and sealed.

An EDI envelope is the same.
When you send an EDI document such as a purchase order to your trading partner, it is packaged in a similar way where the front represents or indicates the address of both parties. The middle part with all the information is the inside of the EDI envelope and the end is the sealing of the EDI document that indicates the end of the information for that document.

In this above picture: ISA, GS and ST indicate the front part and SE indicates the end, sealing or closing of an EDI envelope

2. Segments

A single EDI transaction set can be composed of many segments.

A segment is a collection of related data, such as a ship-to address, or terms of sale information, or a detail line item from a purchase order. In the ANSI standards, there are many segments available for trading partners to put in their transactions.

While there are a few segments that are mandatory (i.e. they are required to be in a document of a certain type), it is up to each trading partner to choose which segments to include in their documents. Each segment begins with a segment ID (e.g., ST, BEG, N1) that describes the type of data elements that follows. Each segment is made up of several data elements.

3. Data Elements

Each element is a single piece of data and is separated by a data element separator.

Let’s look at this purchase order line item:

PO1*1*5*DZ*6.5*CT*CB*18723-5*VN*ABC15~

Here an asterisk (*) is used as the element separator, denoting the end of each element. The tilde (~) is used as the segment terminator, denoting the end of the segment.

Note:  The elements must occur in a specific order within the segment. This order is defined within the ANSI standards. Some elements are used to describe other elements. In such a case, the first element is said to “qualify” the second element and is therefore called a qualifier.

Qualifier elements are often two to three-digit codes that are defined in the ANSI standards. For example, in the line item segment described above, up to seven different item numbers can be sent. But whose item numbers are these? Well, each item number is preceded by a qualifier that tells us whether it is the vendor’s item number, the buyer’s item number, or some other possible identifying number like a UPC code.