David, I've heard you shoot down the reuse value statement many times. Aren't you forgetting the value that companies get from reusing assets that exist in their IT Infrastructure? Isn't the whole point about agility delivering value without building completely new systems from scratch and leveraging what works? Consequently, it's hard to separate reuse from agility.

Maybe the issue isn't reuse, but reusability. (If hair-splitting were an Olympic event, that statement might qualify for a gold medal.)

Isn't it reusability that gives SOA its agility, the idea that the various chunks can be easily plugged together and rearranged to meet evolving requirements?

(Continued on my blog)

Just to clarify a bit, when I wrote about wasted money, I was talking about the ill-concieved marketing and sales efforts of some SOA software vendors and SIs. I don't think companies are wavering in their committment to SOA, but I do agree that vendors rely too much on IT cost savings from code reuse in their marketing of SOA.

IT cost savings are a red herring. Companies can save 100% of IT costs by not using computers at all. The real benefit of a new technology like SOA is how much more money it saves, or makes for the rest of the business.

Agreeing with the last sentence in Ian's post, I believe the ultimate value of investing in SOA will be best measured in business terms. By creating an IT organzition that is more responsive to the business, the business will be able to deliver something before their competitor, consolidate key business processes from an acquisition or merger faster, respond to a new compliance requirement faster, deliver better customer service, etc. This responsiveness may be achieved through service re-use, faster adjustment to service changes, faster integration of new capability, or other aspects. I think the big demand from customers should be, and is becoming, show me the benefits of SOA in business terms. This forces IT and business to have to align, which is a good thing. We should shift the focus from what is the right technical benefit to market and focus on business benefits. This is how, in my opinion, we can accelerate support for SOA inside an enterprise.

I do agree with Dave's notion regarding the Reuse issue, but blame the reason for it being second place as a drive to SOA in the lack of tools in the SOA world enabling easy reuse of the current IT assets. No automatic tool for classifying IT components by Business Context - allowing the reuse by business needs.
Most of the vendors do ignore the legacy issue, trying to sell you new products for "new world".

One way of getting re-use may be through new technology at an SOA endpoint that supports greater business-IT agility.

Our work illustrates one approach to this. We work on a kind of Wiki and SOA endpoint for applications written as business rules in open, executable English.

From the rules, the system can generate and run complex SQL, and can explain the results in English, at the business level.

The system is online at wwww.reengineeringllc.com, and shared use is free.