From Bobby Woolf’s latest;
The beauty of interoperability is that two systems developed completely independently can still work together. Magic? No, standards (or at least specifications, open or otherwise); see Open Standards in Everyday Life. Consider a Web services consumer that wants to invoke a particular WSDL, and a provider that implements the same WSDL; they’ll work together, even if they were implemented independently. Why? Because they agree on the same WSDL (which may have come from a third party) and a protocol (such as SOAP over HTTP) discovered in the binding.
So what about the services that expose WSDL that the client doesn’t know about? What’s the possibility of those components ever interoperating without software upgrades? Zero, of course. That situation is called a silo, and I thought one of the main objectives of this whole SOA thing was to avoid them … wasn’t it?