Alex Kriegel, an active enterprise architect, picked up on my JBOWS (Just a Bunch of Web Services) theme written back in 2005, and shared with us a great analogy that he says has served him well in explaining the difference between JBOWS and full-functioning SOA:
It all started with frustration on Alex's that people just weren't getting the message that putting up some Web services doesn't magically gel into a service oriented architecture: "I found myself explaining – time and again – to the managers on every level why Web services do not equal SOA," he says.
Thus, this metaphor to which the business can relate: mail delivery systems.
JBOWS: Brittle, non-scalable. "If you need to deliver a package from point A to point B, a courier service would be one option. It is fast, it is reasonably secure and it is reliable; you can even trace the way the parcel will be delivered to the recipient, All you need to know is the exact location (address) of the point B. Oh, and you need to pay the courier.
SOA: Economies of scale, built-in fault tolerance. "The second option would be USPS – United States Postal Service. It is a lot cheaper than private courier; it is reasonably fast, reasonably secure and reliable. It also could forward your mail should your intended recipient have moved without notifying you beforehand."