Do we understand SOA?

I came across this posting of Galen Gruman, contributing editor at InfoWorld. He cites Roberto Medrano, executive vice president of SOA Software:

• "Maybe 20 percent of IT folks understand SOA and half of the rest think they do"

He might be right. Perhaps we currently understand that breaking down your business activity into a business component model of autonomous business functions is key to SOA. It is a lot less common thinking to loosely connect these autonomous business functions, events based. I tried to clarify this aspect in SOA Magazine.

And then there is the widely spread misuse of some core terminology. "Experts" tend to speak of "reusable" services. But what they mean is "shareable" services, which is quite a different thing. It makes sense to focus on shareable messages and not only on shareable services. Did you ever hear somebody talk about "shareable messages", typically representing business events? I didn't, while the use of shareable messages really is the key to success. It's shared messages that make the innovation, not shared services.

And what about the idea of loose coupling related to SOA? I quote: "Shared services are disruptive, increasing dependencies and raising questions about what it means to own a service and who should own it." From a lower level IT-perspective this is such a very truth! However it doesn't seem to bother most of our "experts". Not to mention how and why exactly to "share" a service, if a service equates to a properly designed autonomous business function.