The parameter can naturally be more complex than
just a single value, like an object having additional properties, a graph, or even a set
of graphs. In Fig. 10.6, the display function showing clockTime illustrates such a
parameter selection. The design on the left shows time in minutes, seconds, and
milliseconds, whereas the application on the right shows time in hours, minutes, and
seconds. This choice of the central time unit is made from the list of possible
prede?¬?ned values.
Rather than having separate properties for illustrating variation, the main language
concepts can be applied to describe variation. Every model element added to the
speci?¬?cation can originate from the variation. If we again use the watch case, since it is
the best case of a product line among the examples in Part III, placing an object type
like ???Alarm??? means that the application has alarm functionality. Further, variation can
be represented with model connections. By connecting the alarm element, we can
describe how the alarm is set and what happens when an alarm rings. In the same way,
the transition relationships illustrate the variation in execution order within each
application. The same transition relationship is also used to specify execution order
among the applications for a particular product. For example, Fig.
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