The Untapped Promise of XML
Beyond the hype, XML holds great promise for integrating enterprise data. But is it the right solution for your Web-to-host headaches?
Vendor hype machines have been working triple overtime lately around the potential of XML and Web services to "loosely couple" disparate applications and platforms inside and outside the firewall. XML has promise because it's a standard embraced by many vendors, including rivals IBM and Microsoft.
In fact, IBM has positioned XML-based Web services as its next phase of e-business, with its WebSphere Application Server and VisualAge development toolset as cornerstones. Most other major vendors have announced their own flavors of XML-based Web servicesMicrosoft with .NET, Sun with ONE and HP with e-Services and e-Speak. The common ground among these efforts is support for XML-related standards that enable delivery of XML documents, including Simple Object Access Protocol (SOAP), Web Services Description Language (WSDL) and Universal Description, Discovery and Integration (UDDI).
A number of Web-to-host vendors now include support for XML-based data from host systems within their products. One Web-to-host vendor even offers application integration software that encapsulates mainframe and iSeries enterprise applications functions into callable XML objects. Mainframe and midrange functions can then be incorporated into e-business projects.
The greatest potential of XML is in straight-through processing, in which a user can enter required information into a browser-based form, which almost instantly populates a back-end database on any platform. IBM clearly intends to position XML and Web services as a strategy to preserve its mainframe, iSeries and pSeries base. By XML-enabling applications and data, you can make the back-end platform completely irrelevant to the front-end applications. XML provides "independence of data format," in the words of Steve Holbrooke, IBM product manager for Web services. "We can use the highly descriptive capability of XML to describe things that a programmer deals withplatforms, object models, data types and languages."
Sounds great in theory, but let's look at implementation. XML can work well but can also induce headaches. I recently spoke with the CIO of an insurance services firm that had developed XML interfaces for several of its major carriers. The agency's goal is to enable corporate users to enter and send information to the agency's XML-enabled Web site. The data is then immediately forwarded to a carrier, which processes the request on its mainframe and, in an Internet minute, returns quotes for the new business. That process took a lot of integration work between the insurance firm's IT staff and the IT staff of the carriers. "As with most other things, standards and concepts may sound great on paper or on a spreadsheet, until you actually try to implement them and find the practical problems," the CIO told me.
Although the insurance industry has agreed on a single XML standard, there are still issues behind mapping data to individual companies' systems, since no two companies are ever alike. Keeping these mappings current is difficult because each carrier's requirements and processes change, according to the CIO. "You have to develop ways to keep your mappings current. You can do a snapshot of where the information matches and where the unique information has to be collected. But, this has to be maintained and updated on an ongoing basis. Never expect to have anything 100-percent standardized."
This story will be played out across industry group after industry group. Some experts warn that the XML standard is falling into the same traps as EDI did a decade ago. For example, many of the more than 300 XML initiatives underway merely replicate EDI work, dealing with document formats for purchase orders or invoices. Some even call XML the "new Y2K," since it requires massive system overhauls across the enterprise. While XML can help companies achieve straight-through processing and store data with metatags, a considerable investment of time and money will be required to make back-end systems XML-compliant. In the words of one industry analyst, "It's not magic."
For the foreseeable future, mainframe and iSeries applications and data that are XML-enabled will make a fairly smooth transition into the b-to-b Web services scenario. All others are prime candidates for more rapidly deployable Web-to-host strategies.
Joseph McKendrick is an independent consultant and author, specializing in surveys, technology research, and white papers.