Legacy and other systems intended to improve time-to-market or component re-use, such as CORBA and DCOM, were soon outpaced. “Previous strategies were very rigid and brittle,” says Peter Kastner, research vice president of the Aberdeen Group of Boston, Mass. “Any small change could break things.” In their place arose Service Oriented Architecture (SOA), an approach to designing business applications built around the concept of services.
What’s So Different?
“Past integration strategies focused primarily on simplifying the effort required to make large applications interoperate,” says Larry Fulton, senior analyst at Forrester Research based in Cambridge, Mass. “SOA, on the other hand, is about creating or repackaging software components in a way that makes the components themselves easier to use by new or existing systems.”
SOA is differentiated from previous technologies in two ways, says Fulton. First, SOA designs around business process steps, achieving a more naturally reusable granularity of function. Second, the industry has learned a lot about the need to support the adoption of new approaches by also facing the challenges head-on.
“SOA, SOA governance or the processes by which SOA decisions are made consistently and effectively are as much a part of the industry discussion as the approach and the related technologies,” says Fulton. “This did not happen with earlier attempts.”
According to Kastner, early adopters have learned many valuable lessons about implementing SOA. “The complexity has not gone away even though SOA reduces the number of lines of code the organization has to deal with, and the resulting applications are more user friendly,” he says. “Companies further down the road with SOA implementation are telling us that it is best to retain outside services to curb the training curve and that they wish they had done far more planning on the front end.”
“SOA is widely expected to lower the 40 percent on average of the IT budget currently dedicated to integration. It provides more agility and frees dollars for other IT needs,” says Kastner.
Making Connections
SOA is showing yet another major plus: it is highly workable with the push towards IP-based convergence in the wired and mobile communications sectors.
“IP-based convergence offers the same benefits to SOA as it does to other IT efforts,” says Fulton. “Just as IP-based convergence brings together a host of capabilities into a single networking model, those same capabilities can be more easily leveraged when they are bundled into easily integrated SOA services, extending the convergence into the application and architecture levels.”
According to Forrester’s most recent survey data, strategic adoption of SOA and reported measurable benefits continue to grow among North American and European businesses. “All of which demonstrates that unlike earlier strategies, SOA is actually delivering on the promise to improve IT solution delivery,” says Fulton. “The most powerful applications of SOA include the creation of services that closely correspond to business units of work.”