Integrating software quality models into risk-based testing

Risk-based testing is a frequently used testing approach which utilizes identified risks of a software system to provide decision support in all phases of the testing process. Risk assessment, which is a core activity of every risk-based testing process, is often done in an ad hoc manual way. Software quality assessments, based on quality models, already describe the product-related risks of a whole software product and provide objective and automation-supported assessments. But so far, quality models have not been applied for risk assessment and risk-based testing in a systematic way. This article tries to fill this gap and investigates how the information and data of a quality assessment based on the open quality model QuaMoCo can be integrated into risk-based testing. We first present two generic approaches showing how quality assessments based on quality models can be integrated into risk-based testing and then provide the concrete integration on the basis of the open quality model QuaMoCo. Based on five open source products, a case study is performed. Results of the case study show that a risk-based testing strategy outperforms a lines of code-based testing strategy with regard to the number of defects detected. Moreover, a significant positive relationship between the risk coefficient and the associated number of defects was found.