An empirical investigation of the impact of architectural smells on software maintainability
Rodi Jolak, Simon Karlsson, Felix Dobslaw · Journal of Systems and Software · 2025
In recent years, interest in the potential influence of architectural smells on software maintainability has grown. Yet, empirical evidence directly linking maintainability quality attributes — such as modularity and testability — with architectural smells is scarce. This study analyzes seven architectural smells across 378 versions of eight open-source projects. We developed a tool to gather data on architectural smells, associated projects, and package-level quality attributes. The empirical findings reinforce that certain architectural smells indeed correlate with specific quality attributes - a notion previously backed merely by argument. Most architectural smells negatively correlated with project-level testability but not project-level modularity. While there is not a consistent negative correlation with testability at the package level, many smells display a pronounced negative association with the maintainability quality attributes. • The size of projects has a significant impact on both modularity and testability. • Architectural smells show a negative relationship with testability. • Addressing Dense Structure smell can improve modularity and testability. • Addressing God Component smell can improve modularity and testability. • Addressing Scattered Functionality smell can improve modularity and testability.