Normalizing OCL Constraints in UML Class Diagram-Based Metamodels - AND/OR Clauses

Software modeling means producing diagrams. A software diagram, such as a UML class diagram, in general, not refined enough to provide all the relevant aspects of a specification. We need a mechanism to describe additional constraints about the objects in the model. The object constraint language (OCL) is a formal language, OCL expressions are unambiguous and make the model more precise and more detailed. The navigations contained by the constraints increase the complexity of the constraint evaluation. This paper introduces the concept of AND/OR clauses and provides algorithms - constraint relocation and constraint decomposition - to eliminate navigation steps from the OCL constraints appearing in UML class diagram-based models