3 Action semantics at the model level

Action semantics as a package for UML, helps to define the actions in models. Its goal is not to usurp the responsibility of all the other packages such as OCL, but to cooperate with them in a harmonious way. OCL, as a well established part of UML, is still used to specify logical expressions in the new UML configuration. Those logical expressions give the pre- and post-conditions of methods and guards of transitions. Action semantics, however, is used to specify the body of the methods, i.e. their behavior.