Organizational volatility and post-release defects: a replication case study using data from Google Chrome

The quality of software projects is affected by developer turnover. Mockus studied organizational volatility in the context a large switching software project at Avaya. We replicate his model of the impact of organizational volatility on post-release defects. At the time of Mockus's study, Avaya was experimenting with outsourcing and layoffs were prevalent. In contrast, we study volatility on the Chrome web-browser, which is growing rapidly in terms of popularity and team size. Where possible, we use the same factors as Mockus: the number of co-owners, the number of developers joining and leaving the organization, the number of co-changing directories, developer experience and, instead of LOCs, the churn. Our investigation is conducted at the directory instead of the file level. The control variables, including churn, number of co-owners, and expertise all conform with the consensus in the literature that more changes, more co-owners, and lower expertise lead to an increase in customer reported post-release defects. After normalizing by the highly correlated number of co-owners, the number of developers who leave and join both reduce the number of post-release defects. We discuss this unexpected result.