Service identification is not only about finding services that are already there, but also about identifying services that your organization needs but do not yet exist. These services can then be bought or developed. Identification can also result in the need to modify existing services, for example adding additional operations, or promoting existing IT assets into services. The latter is the case when the implementation is already there, but not yet exposed as a service, the service interface and possibly the contract are missing.
Service identification is an iterative process, meaning that you can't identify all the services in one large project all at once. Start small and realize the initially identified services before gradually expanding your service landscape in subsequent iterations.
There are generally two approaches to identifying services—top-down and bottom-up. Let's go into some more detail now.