Software Quality Assurance Practice Exam

In the context of software quality assurance, what does the term 'defect density' refer to?

1. The number of defects relative to project size

2. The severity of defects in the system

3. The ratio of tests executed to tests passed

4. The frequency of bug reports over time

The correct answer is: The number of defects relative to project size

Defect density is a critical metric in software quality assurance that measures the number of defects identified in a software component relative to its size, which is typically expressed in lines of code (LOC), function points, or other quantifiable measures. This metric provides a quantitative assessment of software quality, allowing teams to determine how many defects exist per unit of measurement. The rationale behind using defect density is that it helps in identifying areas of the software that may require more attention during testing and quality control processes. A higher defect density could indicate that a specific module or component may be more prone to errors or complexity, thus requiring further investigation, rework, or additional testing efforts. The other options refer to different concepts within software quality assurance but do not accurately represent the specific meaning of 'defect density.' While the severity of defects speaks to the impact of bugs, the ratio of tests executed to tests passed pertains to testing effectiveness, and the frequency of bug reports focuses on the reporting aspect rather than the inherent quality measured by defect density. Thus, the chosen answer appropriately encapsulates the essence of what defect density signifies within the discipline of software quality assurance.