Work Product (Artifact): Signal
This work product specifies an asynchronous stimulus from one object or instance to another.

The purpose of a signal is to provide one-way asynchronous communication from one object or instance to another.

Signals are a specialization of Artifact: Event that can have operations, attributes, and relationships.

Container Artifact
RolesResponsible: Modified By:
Input ToMandatory:
  • None
Optional: External:
  • None
Representation OptionsUML Representation: Signal. Also commonly represented as a class stereotyped <<signal>>. 

Signals are used to define entities for asynchronous messaging. They are suitable for communication in distributed and concurrent systems. Avoid naming signals in a 'receiver-specific' manner - this limits their generality and usefulness, bearing in mind that signals may be broadcasted to a set of objects. The important thing is to communicate the interesting occurrence the sender has detected (which prompted it to send the signal). A signal may also have a list of parameters which are represented as its attributes. Operations may be provided on a signal to access these attributes.

Since Signals are a specialization of Work product: Event, signal tailoring is dependent on the tailoring for Work product: Event. For example, the Work product: Event information can be captured in textual form (such as a table in the Software Architecture Document), while the Signal-specific properties are captured in a visual model.

More Information