Improving Product Quality Based on QFD and FMEA Theory

This research is based on Quality Function Deployment (QFD) and Failure Mode and Effects Analysis (FMEA) to improve the quality of electro-fusion fittings. QFD is an effective tool to explore customer demand. In this study, QFD is used to identify the key technical characteristics that affect customer satisfaction of electro-fusion fittings, and then AHP is used to rank the key technical characteristics of customer satisfaction. FMEA is a systematic activity in the product design stage and process design stage to analyze the subsystems, parts and processes of the product one by one, and then find out all potential failure modes and analyze their possible consequences, so as to take necessary measures in advance to improve product quality and reliability. In this study, FMEA is used to analyze the causes and consequences of possible failure modes in the process of improving the quality of electro-fusion fittings. CRs were then transferred to specific technical attributes (TAs) by House of Quality (HoQ). Manufacturing processes of electro-fusion fittings were analyzed by FMEA and relative solutions were given to failure models with high Risk Priority Number (RPN) indices. By the integration of FMEA into QFD, the product qualification ratio of electro-fusion fittings has increased by 12% based on the improvement of the technical design and manufacturing processes.