The effects of test driven development on internal quality, external quality and productivity: A systematic review

• This paper examines articles published between 1999 and 2014.
• A total of 1107 articles were collected and 27 were studied in depth.
• The studies have shown an increase in productivity in the academic environment, but a decrease in an industrial scenario, when using TDD.
• Most of the studies (76%) have identified an increase in the internal software quality and even more (88% of the studies) identified an increase in external software quality when using TDD.

Context: Test Driven Development (TDD) is an agile practice that has gained popularity when it was defined as a fundamental part in eXtreme Programming (XP).Objective: This study analyzed the conclusions of previously published articles on the effects of TDD on internal and external software quality and productivity, comparing TDD with Test Last Development (TLD).Method: In this study, a systematic literature review has been conducted considering articles published between 1999 and 2014.Results: In about 57% of the analyzed studies, the results were validated through experiments and in 32% of them, validation was performed through a case study. The results of this analysis show that 76% of the studies have identified a significant increase in internal software quality while 88% of the studies identified a meaningful increase in external software quality. There was an increase in productivity in the academic environment, while in the industrial scenario there was a decrease in productivity. Overall, about 44% of the studies indicated lower productivity when using TDD compared to TLD.Conclusion: According to our findings, TDD yields more benefits than TLD for internal and external software quality, but it results in lower developer productivity than TLD.