Evaluating the Likelihood of Bug Inducing Commits Using Metrics Trend Analysis

Continuous software engineering principles advocate a release-small, release-often process model, where new functionality is added to a system, in small increments and very frequently. In such a process model, every time a change is introduced it is important to identify as early as possible, whether the system has entered a state where faults are more likely to occur. In this paper, we present a method that is based on process, quality, and source code metrics to evaluate the likelihood that an imminent bug-inducing commit is highly probable. More specifically, the method analyzes the correlations and the rate of change of selected metrics. The findings from the technical debt dataset extracted data from SonarQube indicate that before bug-inducing commits, metrics that otherwise are not correlated, suddenly exhibit a high correlation or a high rate of change. This metric behavior can then be used for assessing an impending bug-inducing commit. The technique is programing language agnostic, based on metrics that can be extracted without the use of specialized parsers and can be applied to forewarn developers that a file, or a collection of files, has entered a state where faults are highly probable

Technical Debt Management: Definition of a Technical Debt Reduction Software Engineering Methodology for SMEs

In the past two decades, the metaphor of technical debt has gained significant importance in the field of software engineering. In general, the term is used to describe scenarios when instead of providing a proper solution for a given task, a sub-optimal implementation is used in order to gain short term benefits. Unfortunately, this kind of decisions can - and most of the time do - result in increased maintenance costs and poor evolvability in the long run. Over time, software practitioners further refined the initially source code-focused concept and started to apply the metaphor for a much wider range of software engineering inefficiencies, such as architectural defects, inappropriate documentation or low test coverage. Due to its similarity to financial debt, the analogy has also become a valuable communication tool in situations when there are less technical people involved in discussions. This master's thesis defines a technical debt reduction methodology, which can help SMEs to control the accumulation of technical debt. The proposed methodology can be thought of as a set of steps and good practices that facilitate the long-lasting productivity and profitability of SMEs. Since this field of research is relatively new, the need for publications addressing the topic is still rather high. Due to its numerous negative effects, it is crucial for companies to keep their debt levels as low as possible, which requires a systematic way of managing technical debt. Besides providing such a methodology, the document also intends to raise awareness about the nature and dangers of taking on unreasonable amounts of debt by examining the most important characteristics of the phenomenon. Finally, the thesis presents an industrial case study as well, which aims to showcase how some of the most necessary steps can be taken in practice