There's been quite a bit of discussion across the blogosphere around the "Guerrilla SOA" tactics proposed by Jim "World Wide" Webber, as recently articulated in a video podcast. Check out Rich Seeley's article, which presents both sides of the matter. (Yours truly had jumped in on the discussion here and here.)
Jim makes some additional observations, answering critics of his approach. For example, there are assertions that grassroots approaches such as Guerrilla SOA are simply unconnected SOA efforts that will simply lead to a lot of unconnected SOA efforts, with little to no value for the business at large.
However, Jim points out, the business itself "acts as the connecting glue between all the Guerrilla SOA efforts because they own the processes that feed service development. Far from advocating lack of governance in SOA, I'm about putting governance into the hands of the business and then incrementally delivering to their priorities (and if you're sensible, letting the business stakeholders help drive out the service architecture)."
Jason Bloomberg also weighed in on Guerrilla SOA, noting that while he supports the approach in principle, doing so without an overall plan and governance in place, runs "the risk of building incompatible or redundant services." He advises.
However, Jim Webber sticks to his guns. "Good SOA (Guerrilla or otherwise) is about incrementally delivering business processes packaged as services. The nice thing about this is that any duplication and refactoring happens at the business process level (the source of truth) and the business gets to decide what services are deployed to meet support their objectives."
Jim also observes that "at the technical level we still need to build those services, so our jobs aren't going away. But all that governance stuff is surprisingly as much a business decision as it is the duty of your friendly local-neighborhood enterprise architect."
Let me add to Jim's argument that it's likely that many companies out there, if not a majority, will not have top-level support for a comprehensive, well-governed enterprise service-oriented approach. Instead, many SOA efforts will be mired in organizational politics, finger pointing, or simply a general sense of cluelessness on the part of management. 'Yes, we want business agility and all that good stuff, but we're not going to give you any money or support -- just make do with what you've got.'
The evolution of SOA will be up to movers and shakers in the ranks from various departments to put or pull the pieces together, one by one, to demonstrate the viability of these approaches. For many companies, Guerrilla SOA may be the only way.