Research On Reducing Seals Cost Of LQ Company Based On Lean Six Sigma

In order to solve the high cost problem of the elastomer bellows seals including high procurement cost,backward process technology,and low production efficiency in LQ company,this thesis studied and improved the high cost problem of the seals through the successful application of lean six sigma DMAIC methodologies and tools.In Define phase,the thesis defined the customer’s demands through the key quality characteristics CTQ tree diagram,confirmed the study range by SIPOC diagram,determined the SMART objectives,established the study team and made the DMAIC plan.In Measure phase,the thesis adopted SAP financial analysis module to measure the standard cost of the seals,determined three high cost key factors by Pareto principle,analyzed the measurement system of the seals and measured current CPK process capability status of the seals.In Analyze phase,the thesis analyzed the root causes of three high cost key factors.Firstly,the thesis deeply analyzed the process technology of primary rings by 5-Why method and verified that the wear resistance of the moulded material primary rings was better than that of the grinding material primary rings by the hot water comparison test of the materials.Secondly,the thesis analyzed the process of seal heads pressing assembly through brain storming tool,developed the automatic pressing assembly equipment replacement of manual assembly.Thirdly,through the comparative analysis with the benchmarking of American and Chinese factory,the thesis updated the seals packaging from cartons package into trays package and verified the reliability of the trays package.In Improve phase,the thesis verified that the production process capability and quality of the moulding rings were more stable and controllable than that of the grinding rings by the Xbar-R control chart and CPK process capability analysis tools.The thesis determined the optimal parameters of the automatic pressing assembly equipment by DOE two-level full factors experiment and the height of the pressing assembly surface met the standard requirements of the LQ company.In Control phase,the thesis monitored that the process capability and the seals quality of the moulding rings and the automatic pressing assembly equipment and verified they were stable and controllable by the Xbar-R control chart.The study created the inspection control procedure documents for the moulding primary rings and the standard operation procedure documents for the automatic pressing assembly equipment and the trays package.Finally,on the premise of improving the quality of the seals,finance department calculated the cost saving achievement of the seals,the result of this study exceeded the expected objective of the elastomer bellows seals cost reduction project.This thesis studied and solved the high cost problem of the elastomer bellows seals in LQ company and verified that the effectiveness of Lean Six Sigma DMAIC methodologies and tools to solve the practical problem of the seals high cost in LQ company.The thesis provided the best practice and laid the good foundation for further in-depth application of Lean Six Sigma methods and tools to solve complex and difficult problems of the enterprises.