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ExecutionSpecification on Sequence diagram
The ExecutionSpecification is a graphical notation used in a UML Sequence diagram to represent the execution of action within a lifeline of an object. It is visualized as a thin long rectangle placed on a Lifeline. It is also referred to as a ‘Focus of Control’.
There are two types of ExecutionSpecifications:
Behavior ExecutionSpecification – represents the execution of a behavior.
Action ExecutionSpecification – represents the execution of an action.
A graphic depicting ExecutionSpecification on Sequence diagram
How to draw an ExecutionSpecification
1 You can draw an ExecutionSpecification on a Sequence diagram by selecting the symbol from the Draw toolbar, and placing it on a lifeline – an ExecutionSpecification will only afix itself to a Lifeline – it cannot be drawn into space.
2 When placed on a Lifeline, you can drag on the handlebars of the ExecutionSpecification to adjust its length, to model the active length of the Lifeline representing an object.
3 The top of the ExecutionSpecification rectangle typically coincides with the receipt of a message. The bottom of the rectangle coincides with the completion of an action and can be marked with a return message.
4 You can draw an ExecutionSpecification on top of an existing ExecutionSpecification – nesting them – to denote an object sending a message to itself, or receiving a call back from another object.
5 Optionally, you can hide the name of the ExecutionSpecification by right-clicking on the symbol, and then choosing Display Mode (or View > Display Mode) – then in the Display Mode dialog select either the Symbol Type On Diagram tab or the Selected Symbol tab, toggle on Enabled, and Hide Symbol Name.
See also
Lifelines on Sequence diagram
Messages on Sequence diagram
Generic Line on Sequence diagram
GeneralOrdering on Sequence diagram
Combined fragment on Sequence diagram
ConsiderIgnoreFragment on Sequence diagram
Constraints on Sequence diagram
Coregions on Sequence diagram
Interaction on Sequence diagram
InteractionOperand on Sequence diagram
InteractionUse on Sequence diagram
Observation on Sequence diagram
State Invariant on Sequence diagram
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Sequence diagram