Pattern-based model refactoring for the introduction association relationship

Refactoring is an important software development process involving the restructuring of a model to improve its internal qualities without changing its external behavior. In this paper, we propose a new approach of model refactoring based on the combined use of UML, B and CSP. UML models are described by class diagrams, OCL constraints, and state machine diagrams. We detail a refactoring pattern that allows for the introduction of an association relationship between two existing classes. We illustrate our proposal by giving a case study involving the SAAT (Software Architecture Analysis Tool) system.