Abstract
Open source software (OSS) has become one of the modern software development methods. OSS is mainly developed by developers, volunteers, and users all over the world, but its reliability has been widely questioned. When OSS faults are detected, volunteers or users send them to developers by email or network. After the developer confirms the fault, it will be randomly assigned to the debugger who may be a developer, a volunteer, or a user. These open source community contributors also have the phenomenon of learning when removing faults. When the detected faults are removed, the number of introduced faults decreases gradually. Therefore, this study proposes a software reliability model with the decreasing trend of fault introduction in the process of OSS development and testing. The validity of the proposed model and the accuracy of estimating residual faults are verified by experiments. The proposed model can be used to evaluate the reliability and predict the remaining faults in the actual OSS development and testing process.