Veterans caution that it’s difficult to predict the reusability of services. Sizing the services properly (known as granularity) so they don’t try to do too much or too little is an art. "We have challenges with granularity," says Howie Miller, VP of integration architecture for IBM’s internal IT group. "I’d say 30 percent of our assets drive 90 percent of the return because they are sized better," says Miller. Heffner agrees: "At one auto company I’ve talked to, they had some services that were used 20 times and others that were used only once."

Q: I need to show value to the

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

A: 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."

"Business processes change all the time," adds Praveen Sharabu, director of enterprise architecture and infrastructure for transportation company Con-Way. "Nobody can wait for two years while you document everything, and it will be obsolete by the time you finish."