In an interview, Loraine Lawson asked Gartner Vice President Nick Gall, who is credited with first describing Web-oriented architecture (WOA), to give business and IT leaders the bottom line about the WOA versus SOA debate.
When asked about the origins of the term WOA, Gall said
The earliest entry I can find is back in fall of 2005. I presented at a conference to use the term and Whit Andrew - another one of our vice presidents - blogged about my use of the term WOA [... After observing how web services were emerging outside of ] Gartner's clients - semi-large corporations.
He observed that the architectural style that came closest to resembling this emerging style were RESTful services. but "REST raised a lot of hackles and there was a lot of misunderstanding about what REST really meant". and so a new term was coined. He said,
WOA meant to me was a more Web-centric style of doing Web services: Simpler, less complex, less vendor-driven, just a catch-all for this different style that was emerging.
And he succinctly describes the architectural style with the equation "WOA = SOA + REST + WWW". He described WOA in terms of how the architectural constrains are layered in relation to SOA.
A sub-style of the overall SOA style. A Web service that would count as a WOA should aspire to adhere to all the constraints of REST. But it doesn't have to be 100 percent RESTful. [...]
SOA is an architectural style with essentially five constraints. If your architecture has all five of those characteristics - it's modular, distributable, describable, sharable and loosely coupled - you get the SOA stamp of approval.
WOA goes a little bit further and says adhere to the constraints of REST as well, and those are perfectly compatible. Every one of the constraints of REST, in essence, gives you guidance for how to do the big five [constraints] of SOA.
The traditional SOA found in most enterprises, , he said, as one in which WS*, SOAP, WSDL and related technologies are deployed a certain way and stated that "it's not perfect, but you can describe it. But there's no name for it". He calls this style of SOA, Style X. He elaborated,
SOA is this umbrella term with the big constraints. So far there have been two major sub styles. One is this Style X, which we don't have the name for yet but is this distributed object like, IDL-like, style. And the other major style for SOA is WOA style. Of all the approaches to SOA, WOA has demonstrated the high degrees of sharability and loose coupling [...] And those really are two competing styles. We could do a comparison about the strengths and weaknesses of the WOA style of SOA and this X Style.
He stated that Gartner was researching the strengths and weaknesses of each of the styles currently. When asked How [CIO's] could tell if they should focus on SOA or WOA [and] How they should make sense of all this debate? Gall advised,
Focus in on the two key criteria: sharing and loose coupling. [...] look[ing] back [...] if I haven't seen a large degree of sharing, I would deem that project a failure. [...] I also want to make sure that I get [business process] agility out of it.
He closes the interview with a warning to the CXO's. He said,
If they simply focus on the technology towards doing that, they will get nothing. It's all about focusing on the architecture required for sharing and the architecture required for flexibility and different ways of filling that gap.
Be sure to check out the full interview. What kind of SOA adoption are you seeing in the Enterprise? Let us know
