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XML/EDI: Business information for the 21st century

 
Martin   Bryan
  Consultant
  The SGML Centre
29 Oldbury Orchard
Churchdown   Gloucestershire  United Kingdom  GL3 2PU
Phone: +44 1452 714029
Fax: +44 1452 714029
Email: mtbryan@sgml.u-net.com Web: www.sgml.u-net.com
 
Biographical notice:
 
Martin Bryan
 
Martin Bryan is an independent information management consultant who specialises in the creation of structured documentation using a wide variety of techniques, including HTML, SGML, XML, HyTime and related standards. Author of SGML and HTML Explained , and numerous papers on the role of structured documentation, Martin Bryan has for many years represented the UK on ISO standardization panels relating to structured documentation.
 
As member of the team responsible for managing the European Commission's Open Information Interchange (OII) initiative, Martin Bryan reports regularly on standarization activity throughout the world, and helps to create the standards lists and on-line guides to Open Information Interchange that are published through the European Commission Host Organization's ECHO web site.
 
ABSTRACT:
client-based process control
information flow control
 
The electronic businesses of the 21st century will rely heavily on electronic information flow control. XML provides a method of moving from server-based control mechanisms of the type used with current HTML/CGI applications to the type of client-based control that will be needed to provide end-users with control of their business processes. XML/EDI will allow developers to share knowledge of business flow control processes between applications.
 
 

Introduction
business information
 
This presentation looks at how XML will benefit those seeking to develop integrated business solutions for the 21st century. In particular it differentiates between the server-based approach that are currently used for electronic commerce applications and the more client-oriented systems that will be needed for fully integrated business solutions.
 
 

Today's solutions
 EDIFACT, Electronic Data Interchange For Administration, Commerce and Transport 
HTML forms
 
There are three main approaches to the electronic exchange of business information in use today:
  1. Exchange of EDIFACT and other forms of coded electronic data interchange (EDI) message over specialist networks.
  2. Use of HTML forms to request that information be supplied over the Internet to a central server.
  3. Use of electronic message handling systems to exchange electronically produced documents, including HTML files and EDI messages.
 
 
EDI messages are prepared using a fixed sequence of fields which are encoded so as to reduce the length of the transmitted message. The coding and decoding sequences required are such that setting up interfaces between message servers and other processes is often a complicated, and therefore costly, business. For security reasons EDI messages are typically distributed on specialized value-added networks (VANs), which are typically based on application of the ITU X.400 protocol developed for advanced message handling systems.
 
HTML provides a limited set of displayable data capture field types and a standard mechanism for passing data from the forms to the server that will process the captured data. No record of the transaction is normally retained at the point at which the data is entered. Whilst this is acceptable for transactions between consumers and retailers, it is not acceptable for business-to-business communication.
 
The Internet provides a low-cost means of interchanging messages between businesses. Recent extensions, such as Secure MIME (S/MIME) and Secure HTTP (S/HTTP), make it possible to send messages in a secure way across the Internet. The Internet does not, however, have the built-in message receipt acknowledgment facilities provided by X.400 systems.
 
If a message needs to be recorded both prior to and immediately after transmission over the Internet, as is generally the case for business-to-business communication, it is sensible to record it in the most resuable format possible. At present there is no one universal solution for this. Documents can be exchanged electronically in proprietary formats (e.g. Word documents, PDF) or in more widely acceptable formats (e.g. HTML or RTF) . Other forms of messages are exchanged using plain or encoded forms of text (e.g. EDIFACT). Over the next two years there will be a major shift in message interchange towards using XML as the interchange format between business applications.

 
Electronic Commerce Today

 
 
 

Tomorrow's solution
 
We are already seeing the first generation of applications based on XML. Typically these are based on extensions of the consumer to retailer transactions currently touted under the heading "Electronic Commerce on the Web". Applications such as those defined in the Open Trading Protocol (OTP) allow consumers to select items from a single retailer, or a group of retailers located in an "electronic mall", and arrange for these goods to be delivered, paid-for and, in the case of OTP, even serviced when they do not work as expected.
 
As with existing HTML-based solutions, the models currently being proposed for using XML for electronic trading are server-dominated, and fail to provide consumers with adequate electronic records of transactions. No attempt is made to integrate the trading process with other processes taking place at the client's site. The consumer has no protection in such transactions, having no records that he can produce in court to substantiate any claims. Such an approach is unacceptable for electronically conducted business-to-business transactions.
 
 

XML/EDI: A 21st century solution to business information interchange
 
If XML is to provide a suitable medium for interchanging business messages it must be possible to integrate the messages with a wide range of business processes, including those used in existing EDI-based systems. The goal of The XML/EDI Group is to provide an incremental path for moving data from the existing, unintegrated, methods for business information interchange to an environment where business messages can be readily integrated into an "electonic enterprise".

 
The Electronic Enterprise

 
 
To achieve this goal we need the following facilities in an XML-based business messaging system:
  • the ability to convert existing business-to-business messages to and from XML
  • the ability to display business messages in different ways in different environments
  • the ability to reuse data from one message in another message (e.g. in an acknowledgement)
  • the ability to pass information provided as part of XML messages to other processes within the electronic enterprise
  • the ability to create messages that contain data obtained from other processes within the electronic enterprise
  • the ability to capture new data and integrate it both with outgoing messages and with processes within the local electronic enterprise.

 
XML/EDI - The Framework for Electronic Commerce Communications

 
 
The XML/EDI Group are looking at the fusion of 5 existing technologies to provide these facilities:
  • XML, to provide a syntax for object-oriented message interchange
  • EDI, to provide the message components and business processes required for business-to-business information interchange
  • templates, to provide the processing logic and control process flows
  • transporatable intelligents agents, to implement the various processes
  • repositories, to store details about reusable information components and their relationships.

 
XML/EDI - The Fusion of Five Technologies

 
 
XML/EDI templates will describe the interface between message components, processes to be carried out on these components by intelligent agents, and the way in which message components relate to repositories. At the time of writing the format of these templates is still being discussed. Whether templates will be completely separate from the message, part of the XSL style sheet used to present the data, integrated with the XML document type definition or form part of the message itself is unclear. The following example suggests one possible scenario:
 
<?xml version="1.0" encoding="ISO-8859-1" standalone="no"?>
<?xml-stylesheet href="templates/order-en.xsl" type="text/xsl"?>
<?xml:namespace name="urn:xml-edi:spec:1.0"
                href="http://www.xmledi.net/spec.xml"
                as="xml-edi"?>
<!DOCTYPE Book-Order SYSTEM "dtds/edi-lite.dtd">
<Book-Order Supplier="4012345000951" Name="Book Supplies Incorporated"
            Send-to="mailto:orders@sgml.u-net.com"
            xml-edi:definition="http://www.editeur.org/MIG/bookorder.ent">
<Title xml-edi:definition="lextype.java?#FIXED">
 The Electronic Book Order Form</Title>
<Buyer-EAN Buyer-Name="The ISUG Bookshop"
 xml-edi:definition="lextype.java?#FIXED">5412345000176</Buyer-EAN>
<Message-Date xml-edi:definition="lextype.java?date.ISO8601"/>
<Order-No xml-edi:definition="lextype.java?CDATA[1,20]"/>
<Order-Line Reference-No="0528835"
 xml-edi:definition="http://www.editeur.org/edi-segments/orderline.ent">
<ISBN xml-edi:definition="urn://ISO RA 1234/ISBN"/>
<Author-Title xml-edi:definition="http://www.whittakers.co.uk/catalogue"/>
<Quantity xml-edi:definition="lextype.java?num[1,3]"/>
</Order-Line>
<Order-Line Reference-No="0528836"
 xml-edi:definition="http://www.editeur.org/edi-segments/orderline.ent">
<ISBN xml-edi:definition="urn://ISO RA 1234/ISBN"/>
<Author-Title xml-edi:definition="http://www.whittakers.co.uk/catalogue"/>
<Quantity xml-edi:definition="lextype.java?num[1,3]"/>
</Order-Line>
</Book-Order>
 
In this example a single attribute, derived from a specially created xml-edi namespace, has been added to the definition of all elements in the XML message to describe the processes to be associated with a particular element or group of elements. This attribute must be specified in the form of an Internet Unique Resource Locator (or name). This name either identifies a plug-in process (an intelligent agent) or identifies a specification that defines the relevant process.
 
The xml-edi:definition associated with the root element for the book order illustrated above identifies the specification for an EDI message implementation guideline (MIG) that could be defined by a relevant consortium. This reference could also be used to identify a repository containing a meta-DTD for book orders, which could be used to verify that the DTD associated with the message conforms to industry standards.
 
The Message-Date element illustrates how processes can be controlled locally. The fact that this message component is defined as an empty XML element indicates, in this example, that it is a piece of data that is to be added to the message by the client. The xml-edi:definition associated with the element indicates that a Java program for checking lexical types is to be used to check that the contents entered into this field conform to the rules for date specification laid down in ISO standard 8601. The use of relative addressing for this identifier means that locally cached copies of the program can be used when the message is recalled from local storage, without having to contact the message provider for the relevant message checking plug-in.
 
The way in which the message will be displayed to the reciever can be controlled by adding an xml-stylesheet processing instruction of the type shown in the second line of the above message to the message header. An alternative stylesheet can be specified by the receiver to replace that suggested by the sender. The proposed XML Style Language (XSL) includes facilities for checking the contents of incoming XML messages using the ECMAScript subset of JavaScript, and for storing supplied data in relevant locations on the client system. XSL also allows the presentation format of the received data to be manipulated to suit local conventions, either as an HTML view of the data, or through the use of the presentation objects defined in the Document Style Semantics and Specification Language (DSSSL) defined in ISO standard 10179.
 
By combining the power of XML and related standards with the business processes of EDI and intelligent agent technologies, The XML/EDI Group hope to show how easy it is to develop integrated electronic business solutions based on XML messaging.

 
Electronic Commerce in the 21st Century

 
 
Acknowledgments
    The author would like to thank the members of The XML/EDI Group who helped to prepare the illustrations used in this paper..
 
Bibliography
XML/EDI
The XML/EDI Guidelines (http://www.xmledi.net/guide.htm)
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