Worked on strengthening the diff and merge workflow in the MontiCore/cd4analysis repository by addressing a critical bug in association handling. Focused on the Syn2SemDiff class, implementing logic in Java to accurately detect deleted and modified associations, including support for reversed directions and abstract classes. Applied code refactoring and software design principles to remove unused dependencies and introduce safeguards that skip abstract-class associations during retrieval. These changes improved the correctness of association comparison and merging, reducing false positives and negatives in downstream processing. The work emphasized maintainability and robustness, ensuring more reliable results for complex model analysis scenarios.