An Interaction element is used to describe a system, representing its interactions at varying levels of detail, for review not only by design professionals but also by end users and stakeholders. An Interaction element can contain the following types of diagram:
An Interaction element in Enterprise Architect is treated as a behavior of the classifier it is encapsulated within. It can have parameters and return types, which are modeled using the Behavior tab of the Interaction element's Properties dialog. The element is interpreted as a method of the containing Class in the generated code (see the Generate Code From Behavioral Model topic).
An Interaction element can also be set as the classifier for an Interaction Occurrence in a Sequence diagram, or for a Call Behavior Action in an Activity diagram. Establishing such an association (between a behavior and a behavior call) facilitates adding arguments that can be individually mapped to the associated behavior's parameters.
The behavioral code generation engine expects the Sequence diagram and all its associated messages and interaction fragments to be encapsulated within an Interaction element (such as setupUSB in the example below).
(The IO Class shown above is available in the EAExample model, under Systems Engineering Model | Implementation Model | Software.)