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4 Modeling Use Cases
FIGURE 2-64
A continuous activity for ??? show car usage data. ???
?«continuous?»
act Show car usage data
Car movement
data
Determine car
usage data
Car movement data
Time
Show car
usage data
Car usage
data {stream}
Car usage
data
End usage
updating
?«discrete?»
{rate1/minute}
Display
on/off
?«controlOperator?»
Enable/disable
display
?«overwrite?»
But what if one of the subsystems for phone, radio, or navigation wants to use
the usage data display? The signal display on/off switches the usage data display
accordingly. More specifi cally, the subsequent action is responsible for this. This
action is a so-called control operator , which means that it is capable of starting or
stopping other actions.
To better understand have a look at the detailing 16 of this action in Figure 2.65 .
The action has an output value of type ControlValue . This type is defi ned in SysML
FIGURE 2-65
Detailing ??? display on/off. ???
?«controlOperator?»
act Enable/disable display
Display on/off
{probability0.


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