The five missing pieces of SOA

Fortunately, as standards such as Web services increasingly dominate interoperability, the cost of simple connectivity has fallen. And third-party application adapter specialists such as Attunity and iWay have increased competition and have vastly expanded the number of connectivity options available today.

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A sometimes overlooked benefit of legacy application adapters is that they mask the complexity and obtuseness of many proprietary APIs. The role of a good adapter is not unlike that of a well-composed Web service: It provides a layer of abstraction that insulates the rest of the application infrastructure from all sorts of messiness. Some vendors, such as Software AG, have specialized in the “semantic integration” of legacy applications to XML-based integration backbones.

Packaged applications from companies such as Oracle and SAP already provide some degree of support for standards-based connectivity, typically by wrapping a proprietary API, such as SAP’s Business API, with a SOAP interface. As application vendors make use of Web services and add middlewarelike functions to their own products, the standard method of integrating packaged applications will come to reflect the best practices of SOA.

Even so, dealing with expensive, proprietary application adapters will continue to be the only option for connecting many truly archaic systems to a common integration framework.

There is one silver lining for IT shops with mainframes from companies -- such as IBM -- that have aggressively ported basic Web services stacks to their antique equipment. Ironically, their rigid APIs can be far simpler to expose through SOAP than untangling the mess of APIs found in many client/server systems.

Semantics

Defining the business meaning of transactions and data is the most intractable issue that IT managers face. Although the semantics challenge predates Web services -- vertical industries have been developing their own XML schema for years, for example -- SOAs bring semantics to the fore. In fact, semantic interaction is a central part of well-designed SOAs.

No technology or software product can truly solve the semantic problem. Business and IT managers must ultimately shoulder the hard, painful work of defining and implementing functions and data models for industry- and function-specific processes. Nonetheless, prebuilt components and battle-tested consulting expertise can simplify many of the challenges.

EAI vendors see their greater experience building integration solutions as a hedge against the commodification that Web services standards portend. Tibco’s Kazi puts it bluntly: Software integration “is a party we went to many, many years ago -- we almost started this party.” A cursory look at his company’s Web site reveals specific solutions for industries ranging from telecommunications to health care to transportation.

As they move to support SOA, packaged application vendors are also touting their experience with specific industries and business processes as an asset. In particular, SAP emphasizes its xApps initiative, which represents a Web services-based implementation of business processes that cross the traditional “silos” of vertical and functional systems.

Increasingly, companies are recognizing the value of XML-based standards for their own industries. For example, the financial services industry has developed FIXML (Financial Information Exchange Markup Language), an interchange protocol for bank transactions; and the accounting industry has proposed XBRL (Extensible Business Reporting Language) for describing and auditing general ledger-style records. High-tech manufacturers continue to use the granddaddy of XML vocabularies, RosettaNet, to exchange product and component information in their supply chains.

In fact, many observers say that the dynamics of a company’s industry may be one of the most important drivers as to when and how a move toward SOA will happen. Bob Sutor, director of WebSphere infrastructure at IBM, notes that industries such as financial services are particularly active adopters of SOA. In addition to technology catalysts such as vertical industry standards, he points to a high number of mergers and acquisitions as a major contributor to this trend. Rather than slowly sorting out and replicating information from one company’s systems to another, he says smart adopters should use SOA-style efforts to “actually integrate business units onto the network” quickly and with less disruption than they would otherwise.

In spite of these challenges, most IT managers agree that adopting a service-oriented integration infrastructure is more a question of “when,” not “if.”

Even so, the old adage, “measure twice, cut once,” applies in spades. Without clear business analysis and principles guiding the development, “you wind up recreating interfaces, which is a real nightmare,” Wall Street Access’ Underwood says.

David Sprott, CEO and principal analyst of research company CBDi, agrees but cautions that the transition to a service-oriented strategy shouldn’t be technology-driven. “Using services thinking [helps] to get business and IT on an equal footing. In other words, don’t just do services because it’s cool. Drive activity on the business requirement and ROI criteria,” he says.

Thomson Prometric’s Crowhurst echoes that learning how to represent essential business processes as services is critical. “It takes a cultural shift to change how development happens,” he says. “Compared to that, the technical challenges are just an intellectual exercise.”