The SOA concept isn't new, it's not a technology per se, it isn't just the use of XML and Web services, and it's a good deal more than a development methodology

A leading vendor in the service-oriented architecture (SOA) market space readying itself to put a proposal to a large Australian government department recently brought in an equally leading implementation vendor to quote on the implementation side of the project.

The implementation vendor, using traditional models, estimated the project would take between 10 and 12 weeks and involve 20 people. The SOA vendor rejected that estimate as hugely overblown and asked the implementation vendor to redo the estimate using the new model and modelling techniques. The result? To the implementation vendor's disquiet, the revised estimates suggested implementation would actually take just two weeks, and involve the efforts of just two people.

"Now you can see why the vendors and the service providers don't want this [SOA]," says Gartner vice president and research director Dion Wiggins. "It cannibalizes their existing revenue stream." Yet love it or loathe it, Wiggins estimates that service providers have just three years before they will be forced to take up SOA as mainstream. Once they do they are going to have to look at changing their business models - in terms of consulting at least.

The trend to SOA is inexorable, Wiggins implies, and is already well under way. The average enterprise might still have another three to five years before it can expect to gain the level of process maturity that it needs to truly capitalize on SOA, but the trailblazers in numbers of process-driven businesses - particularly in banking and insurance - are already enjoying early wins.

Brad Kasell, engagement manager, emerging technologies, IBM Software Group A/NZ, says SOA is receiving a lot of attention from all major financial services companies, all of which have already proven the viability of Web services using proof-of-concept or pilot applications and are now looking to scale that technology across the enterprise. Kasell says those SOA efforts can be expected to be multi-year and ongoing.

"Many of these organizations feel that they already have a SOA to some degree - this is as a result of enterprise architecture efforts that have taken place over the past five to seven years. To some extent, there is a feeling that the primary SOA qualifier is that the enabling technologies are more standards-based than those previously available. In fact most of the architectural considerations such as performance, scalability, reliability and availability can apply to any technology, and the concepts are well understood," Kasell says.

Among those institutions the enterprise service bus concept is proving to be very attractive. Although a complex undertaking, this has proven to be quite compelling for early users. "The reality behind SOA is that when deployed properly - that is, when accompanied by the requisite change in the way that companies do business - a SOA offers significant benefits and advantages," Wiggins says.

It certainly has at trailblazer Capgemini, whose services architecture - built off the back of the European's integrated architecture framework and used as the standard model for both internal and external clients - will enjoy its 10th anniversary this year. Australian vice president, technology services, Brad Freeman says for Capgemini the major driver of the SOA is the way it helps the organization understand how it might modify its architecture to get value out of its IT investment. Capgemini does not do much pure architecture consulting, he says, rather it uses a SOA to run its own systems integration projects as a means of getting a "better bang for its buck". But he says many of the consultancy's clients are interested to understand what their environment would look like under a services model, and how they could subsequently tweak that environment to get the best value out of it.

"We're not too evangelical about it [SOA]," Freeman says. "It's just we know that if you build complex environments using a SOA approach, you tend to get a better result, a more flexible result, and the end result is a lot cheaper over a total cost of ownership model. So you build something for 10 years, not for the next 12 months."