Research On Semantics Of UML Models Based On Denotational Semantics And RCOS

Unified Modeling Language (UML), which is good at describing, constructing and documenting software artifacts has been widely used in the process of modeling software-intensive systems. However, UML is half-formalized, which has formalized syntax structure while its semantic part is specified by the natural language. As the result, it is hard to analyse its semantic and check the consistency among the models.In order to solve the problem talked above, providing a formal semantic model for UML models is the best way. The approaches used to formalize UML model falls into two paradigms. One is the transformation approach in which certain UML diagrams are translated to an existing formalism. However, the problem still exists, which shows that the formalized models defined by different formalisms have the deficiency in some aspects, and also it has the inconsistency problem among the models.The other approach is direct approach in which providing the formal semantic models for UML diagrams directly and then provide the combination for different models as to check the consistency. Our work belongs to the second one. Firstly it introduces the Refinement Calculus of Object Systems (rCOS) whose syntax and semantic are based on the Hoare&He's UTP. Secondly, it gives a short introduction about the research of semantics and then constructs the formal models of the UML class diagram,sequence diagram,use case diagram,state diagrams and components diagram. Moreover, in order to support the MDA based development, we integrated the class diagram,sequence diagram,use case diagram and state diagram into the requirement model. We also specified this requirement model by means of the normal form of the rCOS. At last, we discussed the consistency checking among diagrams, and we also provided an example to verify the method we have provided above.We have given the semantic model of the component diagram by means of extenting rCOS in this work, and there would be more semantic model of UML diagrams derived from this framework which is the motivation of this thesis.