Since a smooth manufacturing process and good product quality mainly depend on machines and equipment, every effort should be applied to enhance the reliability of working equipment and system. Even though plenty of researches have been done on system reliability analysis techniques for enhancing productivity and maintenance action, there is no enough study that shows its effect on product quality. Thus, this study aims to investigate the effect of system reliability on product quality using a risk analysis method that utilizes two methods namely, fault tree analysis and process failure mode effect analysis for PVC pipe product which had the highest portion of scrap due to different manufacturing failure reasons in case of Amhara pipe factory. Fault tree analysis is used to structure the logical relation of the system; whereas Process Failure mode and effect analysis is used to assess the risk of each operational step. A total of 56 operational failure modes and 104 failure causes are conducted. Out of them 31 and 41 are responsible for PVC product quality characteristics respectively which indicates that the reliability of the system has a considerable effect on the product quality. Based on pareto analysis, the RPN greater than 192 identified as 20% of causes. The criteria used for selecting a control mechanism were: RPN greater than 192, critical, product related failure mode and product effect contribution. Based on these criteria Preventive, Condition based, and Corrective maintenance strategies were used. For preventive maintenance action the four criteria were used. For condition-based maintenance action product related failure modes and product effect contribution were considered. For the corrective maintenance action, a failure mode having RPN greater than 192, less critical and non-product related failure mode were considered. The research has a great contribution to overcome quality related problem of the company. In addition, the research is unique in method of combining FTA and PFMEA. Key words: Fault Tree Analysis (FTA), Process Failure Mode and Effect Analysis (PFMEA), Product Quality