Activation Bar
An Activation Bar in a UML Sequence Diagram represents the time period during which a participant (Lifeline) is active or performing an operation. In Modeldraw, you can use Activation Bars to show when objects are processing or controlling the flow of the program.
Understanding Activation Bar
An Activation Bar represents the active period of a Lifeline. Key characteristics include:
It shows when a participant is executing an operation
It is drawn as a thin rectangle on top of a Lifeline
Its length indicates the duration of the activation
It can be nested to show recursive calls or multiple levels of activation
An Activation Bar is represented in UML by a rectangular box placed on a Lifeline.
Activation Bars are crucial in Sequence Diagrams for:
Showing the flow of control between participants
Indicating the relative time and duration of operations
Representing nested calls and complex interactions
Creating an Activation Bar
To create an Activation Bar in Modeldraw:
Select the Activation Bar tool from the toolbox
Click on the Lifeline where you want the activation to start
Last updated