Once you have initially created the service interface, you define its functionality by creating a series of operations. Generally, an operation represents an interaction with a single program entry point. In the Interface Mapper you work with one operation at a time. A single service interface typically contains multiple operations.
For COBOL program-based service interfaces, the operations are packaged together in one service, but each operation is independently executable (i.e., only one operation is invoked per service execution).