Code cloning inflates maintenance costs and can lead to inconsistent changes to code. This paper presents the results of a large-scale case study that was undertaken to find out if inconsistent changes to cloned code can represent faults.

Testing and development are increasingly performed by different organizations. Poor alignment between the two threatens to increase costs. In this paper, we propose a conceptually simple approach to uncover methods that were changed but never executed during testing.

Software systems contain unnecessary code, which causes unnecessary costs. We present tool-support that employs dynamic analysis of deployed software to detect unused code as an approximation of unnecessary code, and static analysis to reveal its changes during maintenance.

Cloned code is considered harmful for two reasons:  (1) multiple, possibly unnecessary, duplicates of code increase maintenance costs and, (2) inconsistent changes to cloned code can create faults and, hence, lead to incorrect program behavior.

The economic benefit of a certain development process or particular activity is usually unknown and indeed hard to predict. However, the cost-effectiveness of process improvements is of paramount importance and the question how profitable certain activities are needs to be answered.

Regression testing analyzes whether software maintenance has inadvertently broken existing functionality. We present a casestudy that demonstrates the challenges that regression testselection techniques face when applied to manual system tests.

Modern software systems often contain a considerable amount of third-party code, as they build on a significant number of external libraries. We propose a structured approach to assess the third-party library usage in software projects and identify potential problems.

Static code analysis often reveals thousands of quality defects, which makes it hard to prioritize. Our approach recommends to remove specific defects like code clones, which provides developers a starting point for refactorings.