5 Conclusion

Action semantics is a very powerful tool to formally specify the behavior of UML models. When it is standardized, it will form a new package for UML, which is capable of rigorously modelling behavior and at the same time interacts with other components harmoniously. Model design at both the modelling level and the meta-modelling level will then change dramatically.

As all kinds of actions defined in the basic action semantics are discussed above, it is obvious that action semantics still has flaws, and disputes still exist on some critical subjects. This is natural for such a new development thing in such an evolving field.