Big SOA versus bite-size SOA

Oracle just wrapped up its mega-confab in San Francisco, and there was no shortage of talk about service-oriented architecture.

Oracle continued to solidify and expand its SOA Suite and Fusion middleware offerings, and has its eye on the mainframe market. Thomas Kurian, Oracle's senior vice president, Oracle's intent is to offer what he called a "service fabric" that supports all manner of applications, new and legacy. Kurian also spoke of the role Oracle's Fusion Middleware will play in an emerging business process management infrastructure.

Contrast Oracle's message of Big SOA with the message coming out of Microsoft's SOA confab just a couple of weeks back. 

Microsoft said that it supports an incremental approach to SOA, addressing one business problem at a time, rather than a more grandiose "top-down" approach that involves the entire enterprise. The Microsoft folks said the top-down approach "is marked by a large investment in enterprise-wide technology that often fails to achieve results in a relevant timeframe."

So we have Big SOA versus bite-size SOA coming from the largest vendors. Which is the best approach? Both the bottom-up approach and top-down arguments have their flaws and their strong points. Many say to build SOA with a combination of the two, but, within many organizations, it's difficult to get the buy-in for an enterrpise-intensive top-down approach. This is surely a debate that will surely continue to heat up as SOA goes mainstream.