Factors for Effective Use of Deployed Design Patterns

Design patterns have been advocated by many researchers and practitioners as a means to produce better solutions and reduce efforts in software maintenance. Previous studies use controlled experiments to compare the maintenance efforts by developers having different work experience with and without deployed design patterns. Many experiments primarily focus on the effect of one or two human factors, and have not explored the effects of many other relevant factors. We have performed an empirical study to investigate the relative importance of several factors that may affect the effective use of deployed design patterns. In this paper, we report our findings of the study involving 118 subjects to perform three change tasks on JHotDraw. Interestingly, we find that among the factors examined, both the level of expertise on design patterns and proficiency of the programming language are not significant in terms of maintenance time, while factors such as the familiarity with the application under maintenance are notably more important.