Software Reliability Prediction for Open Source Software Adoption Systems Based on Early Lifecycle Measurements

Various OSS(Open Source Software)s are being modified and adopted into software products with their own quality level. However, it is difficult to measure the quality of an OSS before use and to select the proper one. These difficulties come from OSS features such as a lack of bug information, unknown development schedules, and variable documentations. Conventional software reliability models are not adequate to assess the reliability of a software system in which an OSS is being adopted as a new add-on feature because the OSS can be modified while Commercial Off-The-Shelf (COTS) software cannot. This paper provides an approach to assessing the software reliability of OSS adopted software system in the early stage of a software life cycle. We identify the software factors that affect the reliability of software system using the COCOMOII modeling methodology and define the module usage as a module coupling measure. We build the fault count models using the multivariate linear regression and performed the model evaluation. Early software reliability assessment in OSS adoption helps to make an effective development and testing strategies for improving the reliability of the whole system.