Todd Biske: Outside the Box

I recently attended a conference with a colleague who is new to the world of SOA. We had some conversations after a couple of case studies about whether what was presented was SOA or not. This reminded me of the IQPC conference in Chicago where I spoke. Interestingly, nearly every presenter there began with a definition of SOA. Why is this? I’ve given it some thought, and realized that one of the most critical steps in implementing SOA is actually defining what it means to your enterprise.

One of the classic examples for Web Services is the supply chain model. In this case, services are exposed to partner organizations. This is an example of what David Linthicum calls “Outside-In SOA.” In looking just at one partner’s services, what are the reasons for this service? Clearly, ease of integration is one. How about reuse? That’s a common goal for SOA, although in this case, it would be reuse by multiple partners rather than multiple internal applications. What’s interesting then, is that for this company, the definition of the enterprise must be extended to include at least some portion of the external partners’ enterprises as well.

Continuing to extend this same example, let’s look inside. It is entirely possible that these services at the edge may yield the benefits of SOA, but that the internal view of the enterprise is not service-oriented at all. The implementations behind these services could each be their own stovepipe solution without any elements of service composition whatsoever. In many of these case studies, we simply don’t know.

What I told my colleague was that these case studies were indeed examples of service-oriented architecture applied to a particular problem space, or put another way, a service-oriented application. Everyone has to start somewhere, and these types of problems are well-suited to a service-oriented approach. Achieving a service-oriented architecture, or as Jeff Schneider’s has titled his blog, the service-oriented enterprise, is a far more daunting challenge, and one that will take careful planning driven from the business strategy. Until then, continue to look for the opportunities to apply service-oriented approaches where you can.