The new online interface is built on top of the J2EE-based VFP application that runs on IBM WebSphere application servers. The VFP application uses an underlying advice engine that was built as a service and uses asynchronous messaging to generate a retirement plan based on input from users, said Jeff Dowds, a principal at Vanguard's retail systems division.

Because the online service reduces the number of phone calls between clients and planners, the company now can provide plans to five times the number of clients at a tenth of the cost, Dowds added.

"We've been able to take our advice platform and truly scale it," he said. "We've been able to expose it across multiple channels without having to rewrite the platform."

The program is available without charge to those with more than US$250,000 in assets and for $1,000 to those with $100,000 to $250,000 in assets, Dowds said. The service isn't available to consumers with less than $100,000 in assets.

Jason Bloomberg, an analyst at ZapThink LLC in Baltimore, said capacity is becoming an issue for many companies using customer-facing, SOA-based applications.