Business to-Business E-Commerce: XML's Killer App

Feb. 28, 2000 12:00 AM

Every technology we accept as standard and ubiquitous - from PCs to the World Wide Web - has achieved that level of overwhelming acceptance because of a "killer app" or other enabling technologies. For PCs it was spreadsheets. For servers it was the relational database. The Internet might have remained a collection of academic bulletin boards if it hadn't been for its two killer apps: e-mail and the World Wide Web.

In each of these cases an application emerged that exploited the potential of the new technology to fulfill an unmet need, powerfully and easily. For XML, e-commerce is proving to be the killer application.

Enterprise Business Integration and the Emergence of XML
A fast-emerging driver for XML adoption has been Enterprise Application Integration (EAI) or, more accurately, Enterprise Business Integration (EBI) - the integration of data, applications and processes across multiple functions in the enterprise and beyond.

Before XML, companies had a difficult choice. They could either hard-code point-to-point integration solutions, creating the proverbial spaghetti, or they could adopt a proprietary integration solution and, with it, a proprietary canonical data representation. Either one restricted future options and created an ongoing maintenance burden. Through its openness, simplicity and industry-wide support, XML provides a sound and flexible underpinning for integration solutions.

EAI has already raised the profile of XML considerably. But many companies have lacked the will or the urgency to pursue a systematic approach to integration - and, consequently, to adopt XML - until something came along to give the business a huge push: e-commerce.

Creating a Well-Differentiated E-Commerce Strategy
For many companies initial e-commerce implementations typically focused on providing Web-based product information with a secure order-entry module. While these early efforts have allowed companies to gain a toehold in e-commerce, they were inefficient and ineffective since they were disconnected from the operational systems of the business.

Creating a well-differentiated e-commerce strategy requires the ability to provide unified information to a range of users such as employees, customers, suppliers and partners. Organizations must integrate customer-facing components with front- and back-office applications, as well as with legacy systems. Furthermore, they need to create and deploy integrated business processes that differentiate the business and add real value for the customer.

Those very demanding requirements are certainly far beyond the capabilities of any point-to-point integration solution. To put it simply, you can't do business-to-business e-commerce effectively without EAI. And as the world rushes to XML, you won't be able to do EAI effectively without XML.

The Role of XML in Business Integration
XML fills a vital role in business integration by providing a generalized mechanism for representing and structuring information. XML is in fact a "metalanguage," which means it can be used to define any set of constructs and is hence inherently extensible. As a result, XML provides not only a replacement for HTML but also a flexible framework for representing the structured data associated with databases and application systems. Any data structure can be rendered as an XML document.

Just as HTTP has become the standard transport protocol for Internet computing, XML is rapidly becoming the standard for data exchange. In its earliest applications XML provided a "more powerful HTML" for interfacing structured data with Web-based applications. More generally, it's also emerging as a flexible vehicle for storing, manipulating and exchanging data of all types across organizations, systems and technologies.

The power of XML lies in its ability to represent the data itself and to define its structure and meaning. XML relies on extensible text tags (or elements) to describe data structures and formats. Using XML, an organization can specify a vocabulary of data elements in, say, a customer-processing application such as the name, street address, city/state/zip, phone number and customer number. Different applications can then identify that data, interpret its attributes and then use it appropriately.

DTDs and Schemas
Over the years there have been many initiatives to define standard data representations to facilitate integration between systems and organizations. The more successful have included standards for EDI, the HL7 standard within health care and interbank settlement systems. However, such standards have generally offered limited flexibility, suffered from multiple dialects and been applied only within their narrow domains. As the requirements for a broader approach to information sharing and application integration have emerged, these technologies lack the required generality, simplicity and flexibility. Today the focus for such initiatives has shifted wholeheartedly to XML - indeed, all these historical standards are in the process of being redefined within the XML framework.

The emergence of vertical and horizontal schemas (and DTDs) is what truly facilitates the use of XML for EAI. The first solutions came out of the academic community and covered such areas as chemical structures, mathematics and data documentation for social science (DDI). Many industry trade groups, vendors and consortiums are now defining schemas for their particular industry or areas of special focus. Schemas become valuable to EAI when they provide a standard for vertical markets, such as financial settlements or telephone billing, or a more generalized business function, such as credit verification.

The use of common schemas becomes especially compelling when forging integration with another organization's applications, as in business-to-business (B2B) solutions. These industry agreements eliminate the need for organizations to hammer out their own definitions and secure agreements between each of the individual parties. They also provide a common specification to be adopted by applications' package and service providers.

XML-Enabling Applications
Until recently, packaged applications have imposed largely proprietary interfaces. As a result, traditional integration solutions have required custom connectors to deal with each application's API. Furthermore, API-based integration requires a common contract in terms of middleware (CORBA, COM, DCE, etc.) that in turn creates dependencies and tighter coupling between the systems. On its own, XML may simply be seen as a standardized data representation format; when coupled with HTTP, XML becomes a ubiquitous middleware solution that lends itself to the loosely coupled style of integration required by EAI solutions. In addition, XML is increasingly being supported by other message transports such as JMQ and MQSeries.

In response to the fast-growing demand for interoperability, especially over the Web, major application vendors, including SAP, Oracle and Siebel, are now rushing to add XML-based APIs to their application suites. Such initiatives eliminate the need for custom connectors for these packages.

In addition, a third-party market for XML-based connectors for popular applications is rapidly emerging. For example, as part of its recently announced Open Integration Framework initiative, PeopleSoft will deliver XML-based APIs that enable developers to plug into PeopleSoft business processes without requiring detailed knowledge of the underlying data structures.

For legacy applications, custom wrappers must be provided to deal with the native APIs and to convert the native data streams to an XML equivalent. Given the prevalence of legacy and custom applications, the ability to create new connectors rapidly is a critical factor in the success of integration solutions.

Forrester Research forecasts that application providers will soon bundle XML translators into their products. These translators will support XML and the industry-specific schemas for their target markets. Wherever a set of applications supports a common schema, the need to provide custom data integration and transformation services will be removed.

XSL as a Data Transformation Mechanism
For broader enterprise solutions, however, a requirement will remain for data transformation to support legacy formats and to provide interoperability across schemas. For example, a single organization may support an EDI schema within its supply chain but a totally different schema in its manufacturing systems. A key benefit of XML is that it comes fully equipped with a native data transformation mechanism, XSL (eXtensible Stylesheet Language).

Applying an XSL stylesheet to an XML document produces an output document (typically XML or HTML) transformed by the application of the relevant XSL rules. The stylesheet concept provides a clean separation between the content itself and the specific format required by a target application or output document. By separating the definition of content from the format in which it's used, XML makes it possible to share information across multiple requirements.

In early draft specifications XSL primarily provided a mechanism for manipulating tags, particularly to allow specific formatting elements to be applied for presentation purposes. Today XSL provides not just a formatting capability but also, through XSLT, a full transformation capability able to manipulate both tags and data content.

The effect is that XSL has emerged as a standards-based data transformation capability for XML-based data and the ideal vehicle for the data manipulation aspects of e-commerce.

In traditional integration projects, transformation has been custom-coded or implemented through a proprietary data transformation tool. The advantages of employing XSL for transformation lie in the clear separation of transformation rules from the application programming effort and in its seamless integration with XML.

XSL becomes the natural way to provide schema-to-schema transformation in the XML world. In the future, XML applications' initiatives will not only define the schemas themselves but also specify transformation templates in XSL to make their data readily available to other applications' domains.

Conclusion
XML - The Language of E-Commerce
XML promises to achieve for structured information what HTML achieved for text and graphics on the Web.

XML is rapidly emerging as the preferred data integration backbone within and across organizations and industries.

XSL provides a built-in mechanism for dealing with different data semantics across applications and domains.

XML, in conjunction with XSL and HTTP, provides for the customized delivery of information to the browser, a prerequisite for compelling customer-oriented applications.

Business-to-business e-commerce is fueling the adoption of XML. The Internet has rewritten the rules for supply chain management, redefined telephony, set new standards for 24-hour customer service and spawned new business models. These new Web-based systems must be effectively integrated with applications from partners, suppliers and external service providers such as credit card vendors and shippers. XML is the lifeblood of this new world, and is rapidly turning all other integration approaches into historical curiosities.

About John Spiers
John Spiers is vice president of international marketing and Internet application and performance tools at Sun Microsystems. A well-known figure in the IT industry, John frequently appears in the press and on speaking platforms. He holds a master of arts degree from Cambridge University.