Guiding the Application of Design Patterns Based on UML Models

Software design patterns are documented best practice solutions that can be applied to recurring problems. Although well documented, there are often opportunities to apply them which are overlooked by software designers. This can be the result of inexperience, the sheer complexity of the system, or the fact that design patterns do not always constitute intuitive designs. In this paper, we present a structured methodology for semi-automating the detection of areas within a UML design of a software system that are good candidates for the use of design patterns. This is achieved by the definition of detection rules formalized using the OCL and using a decision tree model. The approach is illustrated on an example GoF design pattern. A prototype tool was developed to show the feasibility of the approach in practical situations, and is used on a case study, producing encouraging results