Classes are a method of categorizing the functions and failure modes within a design so that states and tests can be automatically generated for a specific aspect of a signal. Two types of classes exist to categorize the various failure types:
Hierarchical Classes may be assigned to function classes to extend the class to lower-levels of the design. These need to be linked Manage Hierarchical Classes by the analyst to correspond with the entities of the lower model.
When to Use Classes
Classes may be used to define the coverage of tests or the set of active functions in an object state or design state. Classes should also be used when separate aspect of a signal along a single net need to be filtered when developing tests and states. The classic example is a flow-oriented system—such as a cooling system or a fuel system. The substance in circulation usually has multiple, separately testable characteristics, such as temperature, pressure and flow.
