[论文解读] Quality of Open Source Systems from Product Metrics Perspective

Mamdouh Alenezi, Ibrahim Abunadi|arXiv (Cornell University)|Nov 10, 2015

Software Engineering Research参考文献 17被引用 3

一句话总结

本研究通过产品度量分析开源软件质量，重点关注缺陷密度作为关键指标。研究发现，较大的开源系统表现出更低的缺陷密度，且大多数度量指标与缺陷数量呈正相关——唯独凝聚度-耦合度比值呈负相关，表明代码结构设计影响缺陷易发性。

ABSTRACT

Software engineering and information systems practices seek ultimately to create the flawless product. One of the tools used to improve the quality of software development is the use of metrics. In this paper, metrics retrieved from open source software were analyzed for quality attributes. Defect density is considered a strong indication of the quality of software product. Few studies have taken into consideration the density of defects while looking into quality of software and proneness to defects. Analysis of this study has shown that defect density is relevant to different developers and different product sizes. Thus, open source project has shown to have low defect density and the larger the product the lower the defect density is. In addition, this study has shown that there are different metrics that correlate with each other indicating that some of these metrics have conceptual and practical relevance to each other. Another relationship was tested between the number of bugs and the metrics. Results indicated that most attributes had positive correlation with the number of bugs with exception to coupling between cohesion among methods of class.

研究动机与目标

• 使用产品度量评估开源软件质量，尤其关注缺陷密度作为质量指标。
• 研究缺陷密度如何随项目规模和开发者贡献而变化。
• 识别软件度量之间的关系及其与缺陷易发性的关联。
• 评估各种代码度量与报告缺陷数量之间的相关性。

提出的方法

• 从开源软件项目中收集产品度量，包括复杂度、耦合度、凝聚度以及与规模相关的属性。
• 以每千行代码（KLoC）的缺陷数量来衡量缺陷密度，以评估软件质量。
• 应用统计分析，检验缺陷密度与各种代码度量之间的相关性。
• 检验报告缺陷数量与各项度量（包括耦合度和凝聚度）之间的关系。
• 使用双变量相关性分析，确定度量与缺陷数量之间关联的强度和方向。
• 聚焦于开源系统，以确保数据可得性与实际应用价值。

实验结果

研究问题

• RQ1 不同规模的开源系统中，缺陷密度如何变化？
• RQ2 软件度量（如耦合度和凝聚度）与报告缺陷数量之间存在何种关系？
• RQ3 哪些产品度量在开源项目中与缺陷密度显著相关？
• RQ4 开发者特定因素如何影响开源系统中的缺陷密度？
• RQ5 代码结构度量在多大程度上可预测开源软件的缺陷易发性？

主要发现

• 较大的开源系统表现出更低的缺陷密度，表明规模扩大可提升质量。
• 与专有软件相比，开源项目的缺陷密度显著更低，表明其具有固有的质量优势。
• 大多数代码度量与缺陷数量呈正相关，表明数值越高，缺陷越多。
• 凝聚度-耦合度比值与缺陷数量呈负相关，表明更优的结构设计可降低缺陷发生概率。
• 若干度量（如复杂度和耦合度）在概念和实践层面均表现出较强的关联性。
• 本研究证实，缺陷密度是开源系统中软件质量的可靠指标。