Actors

An actor represents an element that is external to the system. Typical actors that operate on real time, embedded systems are buses (for example, Ethernet or MIB), sensors, motors, and switches.

Actors are a type of UML classifier similar to classes and they can participate in sequences as instances. However, actors have the following constraints imposed on them:

• They cannot aggregate or compose any elements.
• They generalize only from other actors.
• They cannot be converted to classes, or vice versa.

IBM® Engineering Systems Design Rhapsody® can generate code for an actor, which can be used in simulation testing of the system you are building.