Chris Tham says SOA's place at the top of the industry's buzz list could easily see it dismissed as pure hype.
Head of architecture for technology distribution at the National Australia Bank, Tham says there are two views of what an SOA can deliver: "It's an easier way to integrate applications, or presenting a set of services to users and partners." Everything in IT should be encapsulated as services, regardless of the organization's size, she added.
"SOA as a project does not mean SOA as a vision [and] a lot of vendors are selling to both which is dangerous," she said. "SOA is an attractive way to specify IT as a set of processes."
Tham described developing an SOA as "less of a barrier to entry these days" but it requires a "huge cultural and change management program".
"One barrier is resistance from within IT itself," she said. "The SOA technology is quite simple and there is a lot of inappropriate scepticism [so] we did a set of lengthy induction sessions."
NAB had a requirement that ran across multiple systems, so adopting SOA was a way of reducing the integration burden.
"Don't expect SOA to magically reduce cost and development time, at least initially," Tham said. "SOA requires initial development and the benefits may not be realized immediately."
Tham said the bank's vision would be to embrace SOA throughout the organization.
"There isn't SOA across the whole enterprise today and we are in the early stages of planning that vision," she said.
"SOA is not nascent and is not about the technology which is simple.
"It's about the people and how far you want to go. We have a long way to go."
In a presentation titled, The Promise and Pitfalls of Implementing a Services Oriented Architecture, at an SOA conference in Sydney earlier this year, Tham outlined some approaches to this new application infrastructure.
After referring to some of the weird definitions of what an SOA is - from something that will solve world hunger to just another three-letter acronym - Tham and her team came up with this:
"A service oriented architecture is an application architecture within which key business functions are implemented as re-useable services with well-defined, invocable, interfaces, which can be called in a defined sequence to form business processes."
SOA is attractive to an enterprise because the idea of 'services' ties in well with business processes; it is relatively easy to implement and doesn't require complete rewrites of all systems, has broad industry and cross-platform support, and improves heterogeneous interoperability.
But along with the promises of an SOA come the challenges, which include finding the right people, getting the business - including management - to understand and support the concept, and addressing scepticism.
Tham believes the IT industry is littered with the carcasses of 'silver bullets' which tend to fail because of hype and unrealistic expectations about potential impact and benefits. "Utopian ideals are seldom realizable," she said.
Tham questions whether SOA is in danger of being perceived as a silver bullet and sees two possible scenarios at opposite ends of the spectrum - Armageddon and Nirvana. Armageddon could arise where an organization may have hundreds of Web services, multiple versions of each, complex relationships between systems, and be stuck on old versions of packaged applications because of vendor dependence.
Conversely, a Nirvana scenario is where the whole enterprise is implemented on SOA, key business processes are modelled using BPEL (Business Process Execution Language); services are closely integrated with human workflow activities; business processes and services can be dynamically deployed and provisioned on virtualized hardware, and all services are known and well defined.
To work towards Nirvana and avoid Armageddon, Tham says some evangelism may be necessary to make sure the business and senior IT management understand SOA, and "get buy-in and commitment".
Work out how to link business process design to service definitions to implementation to deployment to operations, she says, and understand what your key vendors are doing and how are they going to implement it in SOA. And, to avoid being left behind with the evolution of standards, build a competency centre.
Think of SOA as a "religion", both in a good and bad sense, Tham says. SOA requires enough people to believe in it and have faith in it to make a difference.
Computer Associates principal consultant Stephen Wells said resource pressures, which relate to the reuse of IP and application code, are driving SOA.
"Organizations have the technology in place - particularly if they are developing technology in-house," Wells said.
He recommends determining as a first step, what can be a Web service and, if you're still at the investigation stage, "it's probably too early to debate whether a .Net or J2EE environment should be used".
"Think about a Web services strategy and what the benefits are," he said. "Look at the architecture and applications to help understand what it's trying to achieve."
Wells said ROI is difficult to quantify from a general perspective, but a starting point coul d be to "look at the amount of time it takes to run through a process flow delivered by e-mail" then "compare costs to complete a process".
Many organizations are attending seminars to see how SOAs work, Wells said, making it still front of mind. He believes within 12 to 18 months a lot of organizations will be delivering external Web services.
"SOAs are not just about applications and services, think about how they are managed," he said.