XML cooks up no-fuss e-commerce

Surprisingly, there has been little overlap so far between the traditional world of business-to-business electronic data interchange (EDI) and the newfangled terrain of Web-based electronic commerce.

One of the hallmarks of traditional EDI - widespread use of standard data-interchange formats known as transaction sets - has been almost entirely absent from today's HTML-oriented electronic commerce applications. The new wave of electronic commerce is based on a profusion of HTML-based, application-specific electronic forms. Unlike established transaction-set formats such as ANSI X12 and EDI for Administration, Commerce and Transport (EDIFACT), HTML forms have no facility for defining the precise role, meaning and structure of each data element they contain.

Without universal data-semantics conventions such as ANSI X12 and EDIFACT, business-to-business EDI would grind to a halt as trading partners disagreed on the legal interpretation of fields in electronic documents, such as purchase orders and bills of lading. Moreover, the cost of developing and maintaining EDI applications would be exorbitant because programmers would not be able to rely on standard schema for parsing inbound transmissions into discrete documents, records and fields.

HTML is a flimsy basis for sophisticated EDI. It requires an elaborate set of scripts and applets to define and extract the data elements, attributes and values in a forms-based transaction set downloaded to a browser. Even the vaunted Dynamic HTML technology does not do much to address EDI data-processing requirements, because, like HTML, it was designed principally for data presentation and display.

Fortunately, the World Wide Web Consortium (W3C) has defined and is on the brink of ratifying a successor format for tagging data objects within Web pages. This format, known as the Extensible Markup Language (XML), will allow Web devel-opers to define flexible object-oriented document formats for diverse applications that can be browsed, queried and processed more efficiently than today's flat HTML data structures. Microsoft's Internet Explorer 4.0 already supports XML, and Netscape Communications has promised to include support for it in the next Navigator upgrade.

Some groups have proposed using XML to encode EDI transactions sets. Most noteworthy among these is the XML/EDI Group, a Washington, D.C.-based industry organization that has posted its draft "Guidelines for Using XML for Electronic Data Interchange" on its Web site (www.xmledi.net).

One of the truly exciting things about the XML/EDI Group's initiative, if it ever results in a full-fledged standards suite, is that it would allow a complete set of EDI business rules, document templates, processing software, workflow status and supplementary data - or hyperlinks to all of the above - to be transmitted along with the transaction sets. This would allow new Web-based EDI trading partners to interface their internal systems rapidly to existing interorganizational work-flows, based on industry-standard message formats and process models downloaded in or linked to XML documents. In EDI parlance, trading-partner implementation agreements could come prepackaged with the transactions the partners plan to use, providing first-time partners a no-fuss, no-muss entree to electronic communications.

All of this, of course, is easier specified than done. The XML/EDI Group has bitten off a big agenda of wannabe standard or implementation initiatives, such as standardizing syntax, document-type definitions and field-definition dictionaries associated with XML-encoded EDI transaction sets.

Rewriting EDI transaction sets with XML in mind may take years, given the need to square this effort with the ANSI X12 and EDIFACT standards bodies, as well as the W3C. Thousands of existing transaction-set standards would need to be recoded - a highly political endeavor that could take years and slow the momentum of the XML/

EDI Group effort.

There already is widespread industry support for the concept of XML-based EDI standards, which means the standards bodies should put this effort on their fast-track agendas. When XML becomes a firm standard, organizations using EDI should organize limited extranet pilots and trials that use the standard to envelope standard transaction sets with a range of metadata and hyperlinks to back-end databases.

Once you see the power of XML encoding to pluck relevant EDI data from Web pages and legacy systems, you'll see that it truly does represent the future of data-rich Web application development.

Kobielus, a contributing editor to Network World, is a senior telecommunications analyst with LCC International, Inc., a McLean, Va.-based network design, engineering and integration firm. He can be reached at (703) 873-2474 or at kobielus˙james@ lccinc.com.