Rourke on SOA

Services cost quite a bit to create and deploy, but they are also expensive to maintain and scale. It is very tempting to audit the use of services and charge-back to the departments that are reusing your services. This approach can be very successful in an established, enterprise-scale SOA but it can be disastrous in a company’s early SOA years.

There are many barriers to reuse and to creating a reuse culture. We are all familiar with NIH syndrome (not invested here), connectivity challenges, upgrades tied to dependencies, and potential performance mismatches. Charging for service use adds another challenge. Internal budgets for service reuse don’t exist. Pricing for service reuse will need to be debated and sorted out. And, frankly, the fact that it will cost money to use a given service might just be the excuse folks are looking for to not reuse that service, and to instead write their own version.

Tracking service use is another major challenge. Beyond the organizational changes required to track service use and formally charge other departments, the technology required to do that tracking is major obstacle. Unless you are using a service container or service virtualization platform that provides this functionality out of the box, you will need to adopt a complex service management platform far earlier than otherwise.

Avoid these headaches and start out with a different approach. Create an SOA center of excellence (something you should do anyway) and force each and every department or business unit to share funding for this new group. The center of excellence (COE) should be tasked with:

• building the first SOA projects
• building the infrastructure services
• training other groups who want to build services
• new software purchases required for SOA
• distributing funds to other groups who are building services
• maintenance and scaling of the early services

It is important that services catche on outside the COE, so make sure the funding strategy forces the distribution of funds to other groups who are building out reusable services.

Over time, the funding for this new group should fall off and companies should move to a charge-back model. The first few years an organization builds out services and builds their culture of reuse are very important. Starting with a charge-back model will stifle the adoption of true SOA.