Are suggestions from coupled file changes useful for perfective maintenance tasks?

Background. Software maintenance is an important activity in the development process where maintenance team members leave and new members join over time. The identification of files which are changed together frequently has been proposed several times. Yet, existing studies about coupled file changes ignore the feedback from developers as well as the impact of these changes on the performance of maintenance and rather these studies rely on the analysis findings and expert evaluation. Methods. We investigate the usefulness of coupled file changes during perfective maintenance tasks when developers are inexperienced in programming or when they were new on the project. Using data mining on software repositories we identify files that are changed most frequently together in the past. We extract coupled file changes from the Git repository of a Java software system and join them with corresponding attributes from the versioning and issue tracking system and the project documentation. We present a controlled experiment involving 36 student participants in which we investigate if coupled file change suggestions influence the correctness of the task solutions and the required time to complete them. Results. The results show that the use of coupled file change suggestions significantly increases the correctness of the solutions. However, there is only a minor effect on the time required to complete the perfective maintenance tasks. We also derived a set of the most useful attributes based on the developers' feedback. Discussion. Coupled file changes and a limited number of the proposed attributes are useful for inexperienced developers working on perfective maintenance tasks where although the developers using these suggestions solved more tasks, they still need time to understand and organize this information.