An Empirical Study of the Impact of Waterfall and Agile Methods on Numbers of Requirements-Related Defects

[Background] Agile methods are characterized as flexible and readily adaptable. The need to keep up with multiple high-priority projects and the demand for short time-to-market could explain their increasing popularity. However, whether or not the use of agile methods jeopardizes product quality is a concern. [Problem] This study compares the impact of waterfall and agile software development methods on software quality using defect data from several software development projects in one company. [Context] The company switched from waterfall to agile methods in 2012. [Research Method] The study compares post-deployment requirements-related defect data from projects using waterfall and agile methods. [Conclusion] The results suggest that switching from a waterfall method to and agile method, as they are practiced, may increase the number of requirements-related defects generated in the developed software.