I often talk to folks who believe that SOA is about creating services. While that is partially true it isn’t the complete picture. The goal of SOA is not service creation but business transformation. Creating a service is a necessary but not sufficient condition for SOA success. You create services to orchestrate legacy capabilities, execute business rules, and manipulate enterprise data.
But, all these are done within the context of business objectives (at least you need to aspire to do that!)
Succeeding with SOA involves utilizing services – multiple kinds of services – to implement functionality, automate business processes, and achieve business objectives. As a by product if you follow reuse-friendly techniques and practices you will build up a service inventory that can be leveraged for future projects. But building up a service inventory isn’t the primary objective – it is a by product of executing SOA right. It means designing, implementing, productionizing, and governing services that are of value to your business, to your domain.