EA - IT Architecture V2 > Architecture Specification > Describing information exchanges > Describing a service interface > Creating a service interface
Creating a service interface
You can create a service interface:
• from a library,
• from a diagram using service interactions, for example.
Whatever the point of origin, you can create service interface in standard mode or using a service interface template.
*For more details on service interfaces, see Using a Service Interface Template.
Creating a service interface in standard mode from a diagram 
To create a service interface in standard mode, in a diagram, from a service interaction:
1. In the objects toolbar for a diagram, click Service interaction
2. Draw a link between the two communication entities.
3. In add service interaction window, click the arrow at the right of the field Service interface and select Create a service interface.
The creation window appears.
4. Select the Creation Mode: Standard Creation.
*For more details on service interface template use, see Creating a service interface from a service interface template.
5. Enter the service interface name in the Name field.
6. Click OK.
7. In the service interaction creation dialog box, enter the name of the service interaction using the name of the service interface and click Add.
The service interaction and the service interface are created.
Building a Service Interface Diagram (BPMN)
Creating a Service Interface Diagram (BPMN) 
A service interface is represented by a Service Interface Diagram (BPMN).
To create a Service Interface Diagram (BPMN) from an interaction service:
1. From the Environment navigation menu, open the exploration area Container > Libraries.
2. Unfold the desired library, and then the Service interfaces folder.
The list of service interfaces accessible from the library appears.
3. Select the associated service interface and, in its pop-up menu, click Create Diagram
4. In the dialog box, select Service Interface Diagram (BPMN)
The diagram opens with service interface frame and the two roles representing consumer and the supplier.
*A role is a participant in an interaction service, workflow or process. It can be the initiator, that is the requester of a service, or it can represent a sub-contractor carrying out processing outside the service. A role is an integral part of the object that it describes, and is not reusable. It can subsequently be assigned to an org-unit internal or external to the organization or to an IT component. Examples: client, traveler.
The events, gateways and sequence flows of your diagram follow the BPMN standard.
*For more details on events, gateways and sequence flows, see Managing events, gateways and sequence flows
Defining a Service operation or a Service interface 
In a service interface diagram (BPMN), operations are described by:
• Service interfaces used
• Service operations used
*A service interface use is associated to a service interface. It enables representation of complex exchanges.
*A service operation use represents the usage of a service operation in an service interface.
To create a used service interface used:
1. Select the Service Interface Used button and click in the diagram within the service interface frame.
The service interface appears in the diagram.
2. Open the Characteristics property page of the service interface.
3. Click the arrow to the right of the Specification of a service interface used box.
4. Select Connect service interface from the drop-down list and choose the service interface that you want to use.
*The Service operations page provides access to the list of components of the exchange contract.