The identification of services, that meet the business requirements, is a vital first step in a service-oriented architecture (SOA). In order to achieve this, however, a major challenge is to bridge the gap between business process models and service deployment artifacts. Because of this gap, business analysts, who should formulate the requirements to new services, often do not understand those artifacts. Or non-functional requirements to services are not defined, because they usually are not part of business process models. And finally, business process activities are not suitable to be mapped on services, because they are context-sensitive and generally not reusable. An extensive literature review showed that hardly any research contributions are concerned with this issue. For this purpose a new method is developed, which is focusing on the identification, specification and the management of business functions. Business functions are seen as the abstract building blocks of a business process, which need to be realized and automated by services. They are described in a business language and help both business people to precisely define the requirements to new services, and service developers to identify and deploy adequate services.