Recently while going through a set of questions asked by my fellow colleagues to a customer regarding an RFP, I saw this question. This was an RFP for a packaged software implementation and the question was asked in the context of integration requirements with the other applications in the enterprise.
I brought this, to point out how product vendors and system integrators confuse customers with questions like this. Understanding of the concept is of paramount importance for its adoption. Dave Linthicum has clearly emphasized this in his blog, where he talks about the need for the vendors (I would add the System Integrators) to got o SOA School.
There are some other industry leader who have rightly pointed out how SOA has become a "goal" rathor than a "mean" to achieve business agility. There are certain organizations who talk about ROI of SOA initiative etc... IMHO, rather than starting SOA initiatives, which has become a new name of implementing web services and implementing a service registry (or may be implementing an ESB), organizations should try and inculcate the style in the organization. Microsoft Enterprise Architect Nick Malik has written a very good post (http://blogs.msdn.com/nickmalik/archive/2007/01/16/your-soa-is-jabows-just-a-bunch-of-web-services-and-i-can-prove-it.aspx) ,in which he points out, where the maximum benifits of SOA lie in an enterprise.
A few lines from his post..
"IT projects provide tools for business processes. They automate parts of a business process or collect information or reduce errors. The point is… which processes? In the past, traditional IT only succeeded with the processes that changed rarely"
"The problem is that there is a long list of business processes that occur frequently but that are more difficult to automate because they change frequently"
"That is the SOA sweet spot"
In most of the cases we do not try to understand the customer requires and what are his pain points before suggesting a solution. Therefore, "SOA" has become "magic wand" for the sales guys and consultants.