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Tim Weilkiens

"Systems Engineering with SysML/UML: Modeling, Analysis, Design"

Why does a customer enter their PIN?
The goal is to deactivate the electronic drive-away protection. Formulating it from
the customer ??™ s view, we call this use case activate car ( Figure 2.33 ). As seen in the
fi gure we can also show the information fl ow in the use case diagram.
Next we look at the information fl ow usage right from the reservation system
to the on-board computer. We recognize that it merely responds to a request of
the on-board computer, but doesn ??™ t start a new fl ow. But who or what started the
pertaining fl ow? In an attempt to trace back the fl ow, we hit the customer who
started the fl ow by placing their customer card on the card reader. The result is
the car being unlocked. Describing it from the customer ??™ s view, we call the use
case unlock car ( Figure 2.34 ).
You will notice at the latest when getting to the detailed modeling of your use
case fl ows (see Section 2.4.5) that the fl ow after the one called unlock car is not
yet complete. After this fl ow there is only a predefi ned time interval available for
entering the PIN and removing the car key from the holder.


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