Developers change source code to add new functionality, fix bugs, or refactor their code. Many of these changes have immediate impact on quality or stability. However, some impact of changes may become evident only in the long term. The goal of this thesis is to explore the long-term impact of changes by detecting dependencies between code changes and by measuring their influence on software quality, software maintainability, and development effort. Being able to identify the changes with the greatest long-term impact will strengthen our understanding of a project's history and thus shape future code changes and decisions. Categories and Subject Descriptors D.2.8 [Software Engineering]: Metrics--impact measures, effort measures, maintainability measures Keywords Software engineering, metrics, long-term impact of changes, change dependencies