For example, Figure 2.88 shows the variants for the customer
identifi cation feature in the domain knowledge model, which are required
because we have different access systems. If you compare this version with the
model in Figure 2.67 in Section 2.5 you will see that it involves some work to
create the model structures required. In fact, an independent domain block came
into being from the pinCheckCode attribute.
You also have to fi nd suitable abstractions in the design in order to be able
to map your variants. This means that you describe the things that vary versus a
common basis. If you enrich the model elements by adding information, such as
cost, time, performance, and so on, you can compare your variants in different perspectives.
This allows you to achieve a good information basis for your decision in
favor of the solution that best meets your goals ( Figure 2.89 ).
2.8.2 Model Simulation
SysML offers a rich choice of elements to support an executable model. What we
need are structures (block diagrams), behavior descriptions (activities, interactions,
state machines), and elementary instructions (action model).
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