Building Blocks of EDI Systems

 Building Blocks of EDI Systems: 

Layered Architecture Application/ Conversion Layer Standard Formats Layer EDIFACT or ANSI X12 Data Transport Layer Email, FTP, Telnet, HTTP, X.435(MIME) Interconnection Layer Dial-up lines, Internet, I-way, WAN 15

1) Application Layer

•  It consists of the actual business applications that are going to be connected through the EDI systems for the exchange of electronic information. 

• These applications may use their own electronic record formats and document formats for storing, retrieving, and processing the information within the company systems. 

• For EDI to operate, they need to convert the internal company document format to a format that can be understood by the system used by the trading partner. When the trading partners are small in number, then the converters for various partner formats can be built. 

• But, as the number of partners with different internal formats increase, the task of building converters for each proprietary format to other format becomes overwhelming. 

2)  Standard Format Layer

•  The application layer relies on common agreed formats for operation. 

• Thus, the second critical building block of the EDI system is standards for the business documents/forms. Over a period of time, two major EDI standards have evolved. 

• The first, commonly known as X12, was developed by the Accredited Standards X12 committee of the American National Standards Institute (ANSI) and

•  The second, the International Standard was developed by United Nations EDI for Administration, Commerce, and Trade (EDIFACT) standard. 

a) ANSI X12 Standard

• X12 devised the standards to deal with transactions such as purchase-order placement, order processing, shipping, invoicing and payments, etc. 

• The paper documents related to particular business activities are mapped into a transaction set. 

• The X12 standard defined a set of documents, referred to as transaction sets, for a wide range of business transaction forms.

• Each transaction set is given a numeric code which is similar to the way in most of the paper forms where form numbers are assigned. 

• A transaction set is a term used in the X12 standard for defining the transfer of a single document (purchase order, Manifest, etc.) between the computers of two trading partners. 

b)  EDIFACT Standard 

• Promoted by the United Nations Economic Commission, which is responsible for the adoption and standardization of the messages. 

• The International Standards Organization (ISO) has been entrusted with the responsibility of developing the syntax and data dictionary for the EDIFACT. The EDIFACT serves the purpose of trans-border standardization of the EDI messages. 

• It combines the efforts of the American National Standards Institute’s ASC X12, Trade Data Interchange (TDI) standards developed and deployed by much of Europe and the United Kingdom. 

• The GE.1 group of UNECE/EDIFAC deals with data elements and rules and formats for automated data exchange. The GE.1 group coordinates the six EDIFACT boards set up for Western Europe, Eastern Europe, Pan America, Australia/New Zealand, Asia, and Africa. Asia EDIFACT board (AEB) consists of members like India, Japan, Korea, Hong Kong, China, Singapore, Taiwan, and Malaysia. 

 3) Data Transport Layer

•  The data transport layer consists of services that automate the task of electronic transfer of messages. 

• The Electronic Mail exchanged through the network infrastructure has emerged as the dominant means for transporting the EDI messages. 

• Electronic mail is used only as a carrier for transporting the formatted EDI messages by the EDI Document Transport Layer. ITU-T has adopted X.435 (X.400-based) standards to support electronic data interchange (EDI) messaging. 

• Data Transport Layer X.435 standard consists of the definition of normal EDI messages and a set of EDI "notifications" to address the security requirement. 

• To achieve equivalence to the security control offered by the paper-based systems, it has three types of notifications. 

• A positive notification – It indicates that the recipient has received the document and accepts the responsibility for it; 

• A negative notification- It indicates that the recipient received but refused to accept the document. The reason for refusal is attached with the notification. 

• A forwarding notification- It indicates that the document was received, but forwarded to another recipient. 

 4) InterConnection Layer

•  It refers to the network infrastructure that is used for the exchange of information between trading partners. 

• In the simplest and most basic form, it may consist of dial-up lines, where trading partners dial up through a modem to each other and connect to exchange the messages as illustrated in figure:-

•  The leased lines and I-way, Internet, or any reliable network infrastructure that can provide the ability of interconnection can be used. 

• Through the interconnection, the EDI partners can achieve document exchanges between themselves as illustrated in the figure:-

                                                  OR,

BUILDING BLOCKS OF EDI SYSTEMS: LAYERED ARCHITECTURE

As described by EDI, two key concepts – electronic document exchange and electronic messages – need to be addressed for an EDI system to evolve. The real networking environment that is used for purpose of electronic exchange of information/documents is heterogeneous in nature. Similarly, electronic messages/documents that can be interpreted and understood by various purchase and order processing systems deployed at different vendors are also heterogeneous in nature. Thus, the evolution of a general-purpose EDI system requires addressing the problem of heterogeneity at two levels – exchanging documents over heterogeneous networks and the heterogeneity of document formats.

The general architecture of the EDI system consists of four layers: the application–conversion layer, standard message formats layer, the data transport layer, and the interconnection layer, as shown in the figure.

1)  Application / Conversion Layer

• The application layer consists of the actual business applications that are going to be connected through the EDI systems for the exchange of electronic information. 

• These applications may use their own electronic record formats and document formats for storing, retrieving, and processing the information within each company’s systems.

•  Since each company’s system may have its own proprietary format, which would be used by their system(s), for EDI to operate, they need to convert the internal company document format to a format that can be understood by the system by the trading partner. 

• When the trading partners are small in number, converters for various partner formats can be built. But, as the number of partners with different internal formats increases, the task of building converters for each proprietary format to other formats becomes overwhelming. 

• The fig. below shows several converters for four trading partners with four different proprietary message formats.

2) The Standard Formats Layer

• The application layer of EDI systems relies on common agreed formats for operation. Thus, the second critical building block of the EDI system is standards for business documents/forms. Since the sender and receiver in the EDI systems have to exchange business documents that can be interpreted by all parties, it has necessitated the development of form standards in EDI. EDI form standards are basically data standards in that they lay down the syntax and semantics of the data being exchanged

• The grocery industry sector created the Uniform Communication Standards (UCS) for addressing the EDI standards required for their segment, which were later adopted by several other retail sectors.

•  In Europe on the other hand, the industry developed and adopted yet another set of standards.

• The shipping industry devised a set of standards called Data Interchange for Shipping (DISH), the automobile sector came up with a standard under the umbrella of Organization for Data Exchange by Tele Transmission in Europe (ODETTE).

• The need for an industry-wide EDI standard was widely felt and this lead to the formation of a Standard Committee X12 under the auspices of the American National Standards Institute (ANSI)

•  Over a period of time, two major EDI standards have evolved. The first, commonly known as X12, was developed by the Accredited Standards X12 committee of the American National Standards Institute (ANSI) and the second, the international standard, was developed by the United Nations EDI for administration, Commerce and Trade (EDIFACT)

a) ANSI X12

• The Accredited Standards Committee (ASC) X12 was set up by the American National Standards Institute (ANSI ) in 1979 to develop cross-industry standards for exchanging electronic documents for use by all businesses in the United States. The committee developed ANSI ASC X12, commonly referred to as the X12 standard.

•  Today, EDI standards are firm but not static, because the development of EDI is a continuing effort. Specific industry groups are continuing to evolve new transaction sets that may be better suited to standardization. The X12 standard sets the framework and rules for electronic data interchange. 

• It describes the format for structuring the data. The types of documents that should be transmitted electronically, and the content of each document. The identification numbers for various forms, codes for a variety of fields, and types of information are also defined in the standard. The standard also defines the sequence of information flow.

•  The X12 devised the standards to deal with transactions such as purchase order placement, order processing, shipping, invoicing, and payments, to name a few. In the X12 standard, paper documents related to particular business activities are mapped into a transaction set. It assigns a numeric code to each of these transaction sets, like the numbering of business forms followed at many organizations.

• The X12 standard defines a set of documents, referred to as transaction sets, for a wide range of business transaction forms. 

• Each transaction set is given a numeric code, and each transaction set is used and for defining the transfer of a single document (purchase order, manifest, etc.) between the computers of two trading partners. 

• The data embedded in a transaction set conveys the same information that is contained in the printed version of the document; usually, it is a subset of the whole information on the printed version. 

• The printed version of the document can be thought of as containing three distinct types of information – header, detail, and summary.

 1.The header contains the information that is common to the whole document, such as date; address; to address; terms and conditions, etc. In the sample order form shown in Fig., the following information is the header:

Alpha Electronics Date 24/11/04

1025, Sector K

Aliganj, Lucknow

Purchase Order no. :

2. Detail refers to line items that describe the actual business transaction. In the case of a purchase order, it may contain item number, description, quantity ordered, and price information. In the sample order shown in Fig., the following information is the detail:

3.  Summery refers to the control information and other components that refer to the complete transaction. In the case of a purchase order, it may refer to order value. In the sample order form example, the summary information refers to the following. 

• For each transaction set, extended specification is required. Each of the transaction sets in the X12 standard has a further specification. 

b) EDIFACT – An International Standard

• In 1987, the United Nations announced an international standard called EDI for Administration, Commerce, and Transport (EDIFACT). The EDIFACT standard is promoted by the United Nations Economic Commission, which is responsible for the adoption and standardization of messages.

•  The International Standards Organization (ISO) has been entrusted with the responsibility of developing the syntax and data dictionary for EDIFACT. EDIFACT serves the purpose of trans-border standardization of EDI messages. 

• EDIFACT combines the efforts of the American National Standards Institute’s ASC X12, Trade Data Interchange (TDI) standards developed and deployed by much of Europe and the United Kingdom.

• The GE.1 group of UNEC / EDIFACT deals with data elements and rules and formats for automated data exchange. The GE.1 group also coordinates the six EDIFACT boards set up for Western Europe, Eastern Europe, Pan America, Australia/New Zealand, Asia, and Africa. The Asia EDIFACT board (AEB) consists of members like India, Japan, Korea, Hong Kong, China, Singapore, Taiwan, and Malaysia.

• The basic unit of communication among EDI Trading Partners, defined by EDIFACT, is an interchange.

 3) Data Transport Layer

• The data transport layer consists of services that automate the task of electronic transfer of messages. In a typical purchase process, once a purchase order has been prepared and printed in the standard format, it is placed in an envelope and dispatched through postal or courier services to the supplier. 

• The content and structure of the purchase order are defined in the standards layer and are separate from the transport/ carrier mechanism. 

• The layer utilizes any of the available network transport services such as electronic mail; file transfer protocol; Telnet-based remote connection and transfer; or even the HyperText Transfer Protocol (HTTP) that drives the World Wide Web. 

• Electronic mail has emerged as the dominant means for transporting EDI messages.

•  EDI documents/ messages are exchanged through network infrastructure as electronic mail messages. Electronic mail is used only as a carrier for transporting formatted EDI messages by the EDI Document Transport Layer. 

• The structured message, delivered by the electronic mail, is interpreted by the receiving software, which is capable of comprehending the structure of the EDI standard information.