Abstract-Defect remains in the whole life of software because software is developed by humans and 'to err is human'. The main goal of well-organized software defect management process is to produce quality software with the least number of defects to reduce the impact of problems in the organization. Defect management process includes three levels which are defect detection, defect analysis and defect prevention to eliminate and mitigate the potential defects. At first level test the software work product until the entire defects are identified and fixed. The second level is defect analysis in this level previously identified defects are analyzed and time is spent to look their root causes and why they were not detected earlier. The ultimate goal of third level defect prevention is to prevent the defects from recurring in the future. The research question of this study is how to produce quality software with the least number of defects? A well establish a defect management process is one of the success factors of producing a software system within the time and budget. In this paper author have proposed a defect management process model and finds observations by applying the proposed model in one of the case organization. The major contribution of this study is to establish a defect management process model in an organization to reduce the number of defects and produce a quality software product.Index Terms-Defect management process model, ITIL defect management model, defect detection, defect analysis, defect prevention, radial analysis, ODC, MR classification, ODC-CC, RCA, FMEA, FTA.