Relationship between design patterns defects and crosscutting concern scattering degree: an empirical study

Design patterns are solutions to recurring design problems, aimed at increasing reuse, code quality and, above all, maintainability and resilience to changes. Despite such advantages, the usage of design patterns implies the presence of crosscutting code implementing the pattern usage and access from other system components. When the system evolves, the presence of crosscutting code can cause repeated changes, possibly introducing defects. This paper reports an empirical study, in which it is showed that, for three open source projects, the number of defects in design-pattern classes is in several cases correlated with the scattering degree of