Impact of Agile Practices on Digital Continuous Delivery Projects

Using System Dynamics, the author investigates the impact of four popular agile practices on the quality of digital continuous delivery projects considering the intricacies and dynamics of a typical continuous delivery project. Specifically, the impact of Test Driven Development (TDD), Pair Programming, On-site Customer Involvement and Pair Testing are investigated. Simulation results showed that TDD, pair programming, and on-site customer involvement improve the pre-delivery quality of continuous delivery projects by 30.6%, 8.5%, and 60% respectively, while pair testing improves the post-delivery quality of continuous delivery projects by 9.86%. Statistical tests confirmed the effectiveness of these practices, except pair programming whose impact was statistically insignificant. The PCDM was further explored to determine the cost-effectiveness of pair programming, pair testing, and TDD by calculating the Return on Investment (ROI) of each of the practices. The ROI for TDD, pair programming, and pair testing were 0.34, -0.60 and -0.64 respectively. Hence, from an economic perspective, only TDD is worth adopting in digital continuous delivery projects.