In this era of XML Web Services, where open technology is given so much of thought and importance, Electronic Data Interchange (EDI) is still used as a format to exchange data electronically across the world. The data exchange is secured and fast, and eliminates the use of paper for issuing purchase orders, invoices, shipping & delivery notes, etc. Electronic mapping is the process of translating the source's data/documents to EDI format. These documents adhere to the EDI standards and can be read at the destination. The working of EDI is similar to the traditional method of data exchange. Initial research has to be done before creating a document. However, the basic difference between the two methods is the usage of paper. The working of EDI can be explained in three simple steps -

• First prepare the document that is to be sent. The document will be created in the electronic form using databases and spreadsheets.
• Convert the data into EDI format by using an EDI translator.
• Send the EDI document(s) to the client via transmission media.

To explain the use of EDI in daily business transactions, let us take an example of purchase order processing. The daily purchase of goods in any company needs a purchase order as an approval document. Generally, printouts of the POs are taken, and they are sent to the supplier via post or courier. However, by using this technology, there is no need to send physical copies of the documents to the suppliers. By installing an EDI translator, here is how companies can send these documents electronically.

• The buyer creates the purchase order and stores it in his computer.
• He creates an EDI version of the document by using an EDI software, and sends it to the supplier's EDI system.
• The supplier's EDI translator receives the document and updates the supplier's system.
• The supplier's system generates a PO acknowledgment that is sent back to the buyer's system.

This process is faster than the traditional one, and it is also a more secured method of sending documents. ANSI X12 is the standard format for EDI that is chartered by the American National Standards Institute. A standard EDI message is made up of an envelope and different structural elements. The EDI message format is given below:

Communication Transport Protocol	Computers coordinate their communication
ISA (Interchange Control Header)	Beginning of interchange Contains interchange identifier, sender & receiver IDs, etc.
GS (Functional Group Header)	Beginning of functional group Contains group type, group identifier, version of standard used, sender & receiver IDs
ST (Transaction Set Header)	Beginning of transaction set
DATA SEGMENT (data to be transmitted)
SE (Transaction Set Trailer)	End of transaction set
GE (Functional Group Trailer)	End of functional group Contains group identifier similar to header & number of transaction sets
IEA (Interchange Control Trailer)	End of interchange group Contains interchange identifier similar to header & number of functional groups

For any purchase transaction, it is mandatory for the buyer to raise a purchase order and send it to the supplier. The supplier, upon the receipt of the PO, has to send an acknowledgment to the buyer. The 'paper' form of the PO is as follows: The same information can be translated into an EDI format, called an 850 Purchase Order. This document is sent to the supplier's system via the translator. The supplier's system automatically sends an acknowledgment to the buyer, upon the receipt of the document. The PO in the EDI format will have the following entries. *The entries in bold are the ones that will appear in the PO. The information regarding each field is also mentioned below the entries. The companies that make use of this technology for their data transfer can choose the method of transmission that is suitable for their businesses. The electronic data interchange standards were designed in a manner so as to ensure that they were independent of communication and software technologies. The standard methods for EDI transmission are serial communication, web, peer-to-peer, value-added networks, POP3/SMTP, AS2, etc. *The term 'Trading Partners' is used to refer to organizations that exchange data with each other. These organizations need to agree on the information and the method that will be used to transfer the information, before starting the process. Peer-to-Peer: A single connection is set up between two companies and data is exchanged. This method is secured, as there is a dedicated connection between each trading partner. Thus, there are less chances of data leak. This method of EDI was brought to prominence by Walmart. Serial Communication: In this method, one of the traders has one or more modems for receiving incoming calls, and the other trader has to call on these modems by using their own modem(s). Many traders use dedicated leased lines for this purpose. Web: After years of development, the Internet is now being used as a method of transmitting EDI. All the EDI files are transmitted by using Internet protocols like FTP, SFTP, FTPS, and AS2. Walmart declared the Internet as a better option for EDI over the traditional VAN, in 2003. Since this announcement, the Internet is the most widely-used medium for EDI. VAN: Value Added Networks are like traffic controllers. They receive data that is to be exchanged, identify the 'from' and 'to' information, and then route the data to its destination. Thus, the data is safely sourced to the destination. Apart from this, VAN also provides additional services like retransmission of documents, audit trails, and alerts the sender and receiver about the data transmission and reception. VAN also acts as a gateway if the hybrid transmission method is used. AS2: A secure method of transmission of data over the Internet is EDI via AS2. AS2 (Applicability Statement) uses the concept of peer-to-peer communication. In this method, the client and server are connected, and the AS2 'calls' for the destination whenever there is data ready to be sent. If the destination responds to the call, the data envelope is sent to it. This envelope contains data in an encrypted form that needs to be decrypted at the destination. Digital certificates are used for securing the data. POP3/SMTP: The EDI files are sent as attachments to the destination. These files are sent with the MIME email as an attachment to the EDI trading partner. The data that is sent over POP3 is password-protected. As EDI gained popularity, the need for a more defined standard arose. Over the years, the Internet Engineering Task Force (IETF) has been standardizing the protocols used by the various methods employed in EDI. The IETF also revisits their standards every year and updates them if necessary, to keep things at par with the latest advancements in technology. The two most widely-used EDI standards today are: ANSI X12 (American National Standards Institute X12): This is the EDI standard used across North America. UN / EDIFACT (United Nations Electronic Data Interchange for Administration Commerce and Transport): This is the most widely-used international standard. The standards defined have been very beneficial as they allow diverse organizations to exchange large amount of information very efficiently, both in terms of time and cost. The standards basically form the building blocks of EDI, and specify which parts of information are mandatory, which are optional for a particular document, and also defines the rules for the structure of the document. EDI mapping is the process which defines the relationship known as the map, to move specific bits of information from the source to the destination. An EDI translation software uses the map that is developed during the mapping phase, and takes the information from the input file (source) to the output file (destination). Along with this, the EDI translation software can perform validation on the data. These validations have to be predefined on the map. If you have an effective EDI map, you will be able to exchange data with your partner organizations very efficiently, thereby increasing profits. However, in case of ineffective EDI mapping, your resources will be tied up, and will cause plenty of issues that will impact your organization as a whole. It is therefore very important to hire a skilled EDI mapper and programmer, especially if you plan an ongoing map development project. Electronic data interchange translation software provides an interface between the internal systems of an organization and the EDI format. For a document that you will be receiving, the application will accept the file, validate it ensuring that it meets all the standards set, and finally translates the file acceptable by the organization's ERP. For a document that is being sent from your organization, the translator reads the file from your ERP system and converts it into an appropriate form. It then validates the file to ensure that all standards are met, and then sends the file across to your trading partner. The entire to-and-fro flow of the document can be tracked at all points, to ensure that there is no loss of data. The market is flooded with software that help implement electronic data interchange. These software are generally user-friendly, and come with plenty of documentation and manuals, but one has to familiarize themselves with the various data types and map development that the software uses. Along with this, the user also needs to be aware of the standards used by EDI in general, and the organization in particular. Some of the software companies that offer EDI Mapping software are:

• Pro_EDI
• Aetna EZConnect
• Gentran
• Softshare Vista
• Softshare Athena
• RedTail
• MapForce
• Mercator
• eLife Coupler

The electronic form of data interchange has many advantages over the traditional paper form of interchange.

• Computer-to-computer or network-to-network exchange is faster.
• The cost involved in sending documents is less.
• Labor time required to carry out the entire process is also less.
• Business transactions are faster, thus reducing lag time.
• Expenses such as freight costs and emergency expenditures are reduced.
• The electronic information regarding the business transactions is readily available to the management at any given point of time.
• Security and authenticity of the data is maintained.
• JIT (just-in-time) delivery and product tracking becomes easy.
• Reduction in shipping and billing errors.

Electronic data interchange saves a large amount of money by providing an alternative, or in a majority of cases, replacing the flow of information by human interaction and paper. Along with the various advantages that it offers, the greatest advantage is that by eliminating the use of paper, resources of nature are preserved in a huge way.