Last month, Burton Group analyst Richard Watson took a critical look at how reuse of services in SOA is calculated. He concluded that these calculations often overstate the savings you can use from reusing services.

But CTO and IT consultant Mike Kavis says there's one big exception: Service reuse can deliver a “big ROI” when you're using it to integrate with external companies or business partners.

Kavis' company is a technology aggregator, acting as a sort of virtual middleman between companies involved in moving products and those that sell products. Reusing services lets them bring on new customers quickly and easily, Kavis writes:

We want each one of these external entities to use the same standard interfaces that we build and reduce the need for customization and exception processing. Reuse to us comes in the form of standard messages that are configurable. The huge benefit here is that we can quickly connect to new customers and/or partners by reusing our standard interfaces and making minor configuration changes to accommodate certain allowable customizations.

He adds it also makes the integration process “repeatable, simple, and standard” because there is one common, well-defined interface. Reuse also gave the company a competitive edge by supporting faster deployments.

As soon as I read his story, I gave myself a big dope slap, because I remembered a similar reuse situation I'd written about last year. Craig Sutter, technical director for VetSource, shared how his company shifted to a service-oriented architecture so it could reuse services from its e-commerce platform. VetSource sells veterinarian pharmaceuticals, but it wanted to allow clinics to set up their own online retail sites for consumers that basically connected back to VetSource. In doing so, the company hoped to reuse as much of its existing e-commerce platform as possible, so it switched to a service-oriented approach.

It wasn't a no-code solution, but SOA did help VetSource bring new clients online faster. It also simplified integration and allowed VetSource to respond to new business requirements faster.

So, despite the pooh-poohing of reuse, there are great examples where reuse of services did pay off, both in terms of simplifying integration and speedier deployments. From the examples I've seen, the key factor is whether you're hoping reuse will happen internally or you're planning to reuse services exerternally to better connect with partners or customers as part of a broader business strategy.