ABC: An Introduction to Service-oriented Architecture (SOA)

What is service-oriented architecture (SOA)? Do you need one? And if you do, what are the first steps you need to take to create an SOA of your very own?

How do I balance the need for architecture planning in SOA with the need to prove value to the business quickly?

Architectural planning is time-consuming. Service-oriented development, drawing upon well-known programming principles and widely available technology standards (such as SOAP, HTTP and so on), can happen a lot faster. But the two need to happen in parallel, say experts. "We do development projects as needed, and then on the side we have a longer multiyear project of mapping out the processes and building enterprise-level services," says Kurt Wissner, managing director of enterprise architecture and development for American Electric Power (AEP). "People need to see the benefit of SOA pretty quickly. That’s why I like the project route, because otherwise you don’t have anything tangible to sell to anyone about why you’re doing this."

While it would help to have the architectural plan and the process mapping in place before building the services (to improve the chances for reuse), architecture planning has no short-term payback, which can be devastating. "I tried to boil the ocean at another company and I failed," recalls Wissner. "We did a big multimillion-dollar architecture plan that duplicated what we already had. It didn’t provide much value over traditional point-to-point integration, and we had nothing to show for our efforts. If you start with the entire enterprise, there are too many risks you might fail."

By taking the enterprise planning in smaller chunks at AEP, Wissner can more easily recover from setbacks. "We’ve had hiccups but could take corrective action because the issue wasn’t that big," he says. "If you break it into simpler pieces, it’s more easily digestible."

How do I know which services will provide the most value for my investment?

When in doubt, start with processes that involve customers, directly affect revenue and address a specific pain point in the business. A 2006 survey by the Business Performance Management Institute found evolving customer needs and preferences to be the top driver in business process change or the introduction of new applications, followed by competitive threats and new revenue opportunities. (Cost savings was a distant fourth.) "Externally facing applications are the ones that provide the most business value, and they have a good set of change requirements that come up very often," says Daniel Sholler, vice president of research for Gartner. "If you can improve those applications by 10 percent, it’s better than improving lower-level applications by 50 percent." Of course, adds Sholler, SOA may not provide more value than, say, a good packaged application. "But if it’s something you would have to build yourself anyway, you need to do it service-oriented," he says.

How will SOA affect my IT group?

If you have a decentralized company, be prepared for a struggle. SOA drives centralization. Indeed, it demands it. "You have to have someone heading it up, and you have to have one individual or small team manage the architecture," says Mike Falls, senior system engineer for Fastenal, an industrial and construction supply company. "If each team is left to itself, they may each come up with different ways of building services. You need one group, one set of research and someone to make sure the development groups are sticking to the service development methodology."

As the service portfolio grows, the development process may begin to look like an assembly line. "It becomes a factory," says AEP’s Wissner. "You have these different project teams that you funnel work through, and they can grow and shrink as required."

Once the SOA factory gets ramped up, expect to add more project managers, business analysts and architects as the productivity of the developers increases, says ProFlowers’ Hall. "Two developers can now do the work of six," he says. "That means the architects and project managers are running to keep up with the output of the engineers. We are probably doing 50 percent more work than we did three years ago."

Those programmers need to understand object-oriented programming and distributed applications—and that means an investment in training. According to the CIO/Computerworld survey, only 25 percent of respondents have the staffs they need for SOA—49 percent said they are planning or have training programs in place for current staff to bring them up to speed.