Discovering services in the Services Registry 
In Service-Oriented Architecture you have one or more service providers on the one side and one or more service consumers on the other. The service providers offer certain business functions as services and publish their interfaces.
The services are to be described in such a way that they can be found easily and used in various applications. Consumers use several services that may come from multiple service providers to create new functions: this is called “service composition” or “service orchestration”.
Central Services Registry
When using services we distinguish between the service provider and the service consumer. In the simplest case, we can assume that the service provider – the person who provides the services – knows the service consumer and informs the latter where the services can be found. However, this contradicts the idea of a global service platform. What makes using Web services attractive is the idea that applications can be built from services that are available in a central registry, in this case in the Services Registry.
The Services Registry (SR) is a registry for Web services, which is located centrally within an SOA landscape. The SR contains information about services provided in that landscape, with references to the services’ relevant WSDL metadata and to the locations of the callable service endpoints. The registered services are classified using semantic-rich classification systems to enable browsing of services by classification.
The Services Registry is a central place for developers to find available Web services that they can reuse. Administrators can find available service endpoints and manage connections between consumer and provider systems. The Services Registry provides support for SAP and non-SAP applications.
The Services Registry ensures visibility in an SOA landscape providing answers to questions such as:
Where are services located in the landscape?
Which services are modeled but not yet implemented?
Which services are already configured and can be called?
Are services that I have published in the Services Registry being used?
How can I define different user-specific views in the Services Registry?
ES Workplace
The Enterprise Services Workplace in the SAP Developer Network (SDN) provides a central source of information for getting to know enterprise services. It also features a publicly available Services Registry. You can integrate this registry with SAP NetWeaver Developer Studio, and import WSDL documents from the ES Workplace's registry into a consumer application for processing.
A query user interface of the Services Registry has been embedded in the respective tools in the development environment. Developers can retrieve WSDL files of the services published on the ES Workplace directly and select them for consumption.
Access to ES Workplace Services Registry: http://sr.esworkplace.sap.com
Prerequisites
The UDDI Server and the central Services Registry have been configured in your system landscape.
More information: Configuring the Services Registry
Features
You can search or browse the Services Registry by classifications to find available service definitions.
More information: Searching and Browsing Service Definitions
Before using a service endpoint you can test it.
More information: Testing Service Endpoints
You can search or browse the Services Registry by classifications to find service groups.
A service group bundles all service calls that are provided by the same logical service provider. If a service definition is assigned to a service group it indicates that the service is used by a consumer.
More information: Searching and Browsing Service Groups
Additional Administrator's Tasks:
Classify service definitions using existing classification systems.
More information: Classifying Services
Publish third-party service definitions to the Services Registry to make them visible in your SOA landscape. Provide a link to the documentation of the service and classify the service definition.
More information: Publishing Service Definitions Using the Services Registry
Create new classifications in your central Services Registry.
More information: Managing Classification Systems
To restrict the view of users to certain service definitions, define permissions.
More information: Defining Services Registry Permissions
Synchronize the content of your test and productive central Services Registry.
More information: Importing or Exporting Services Registry Content
Detect unavailable service endpoints that are published to the Services Registry.
More information: Cleaning the Services Registry
Remove service definitions from the Services Registry.
More information: Removing Services from the Services Registry
Use the Services Registry APIs.
More information: APIs