Research On The Improvement Of Car Seat Design Quality In X Company’s R&D Stage

The Six Sigma tool DMAIC(Define,Measure,Analyze,Improvement,Control)are generally used in existed processes or existed produced,DFSS(Design For Six Sigma)is more suitable for new product and process.Currently,X company’s seat development phase is using DMAIC to solve the technical problems,such as: electric adjustment is not sensitive,cushion’s final dimension has deviation,excessive volatiles.Such as these issues caused a lot of time to fulfill the needs of plant process.Since quality tool: DFSS was not involved in early stage,there was a lack of interpretation of the “abstract” demand from consumers in the research and development stage,and the key of design will be lost from customer’s satisfaction.This thesis mainly from the perspective of customer needs,through introducing the background of X company and product to raise existing problems: the seat space comfort cannot be quantified and no priority in development.Through the IDDOV in DFSS quality tool,it includes: Identify,Define,Development,Optimize,and Verify.It’s a specific research tools,and further clarifies the research value and practical significance of the application in Six Sigma design by following specific steps.Identify phase: use fishbone diagram to find all the technical factors affecting the seat,use stratification to filter out the possible factors,then to use the questionnaire to understand the satisfaction,and finally find the customer attention content through check-sheet.Define phase: Based on six key factors,it will be expanded into 9 customer requirements.Through QFD(Quality Function Development),the customer attention will be reduced to 4 change items.Finally,2 items can be determined through the Quadrifid Graphs Model to improve customer satisfaction immediately.Development stage: Based on 2 items,to expand them through the system diagram layer by layer,and through the design requirement between seat,vehicle,and the dimension requirement between the seat and the adjuster,we can get the key information of adjuster.Optimize phase: Based on the parameters of the adjuster,DFMEA was used to evaluate the risk level,and can get the content which need to be improved urgently.Verify phase: Through the customer survey of improved products and comparison with previous products to verify IDDOV measures.