The Study Of The Quality Improvement Of SPC Application For Company D

Statistical process control(SPC)is an effective method to control the product quality during the production process.Especially in recent years,with China becoming the main market of the world's enterprises competition,product quality and cost are becoming the indispensable competitiveness of the company.The effective use of SPC quality control method is an effective means to improve the competitiveness of the enterprises.This thesis focuses on the high defect rate of D company's product qualified rate in the process of production.After the comprehensive understanding and deep analysis of the reasons for the high defect rate of product qualified rate,and based on the Six Sigma DMAIC procedure,SPC technology is used to deal with the data selecting from the manufacture procedure.Base on the analysis of the verification of sampling method,the control of the sampling cost and the improvement of inspection efficiency,this thesis assesses the repeatability and reproduction of the person and inspection instruments by the measure system analysis,which solidified the base of data collection and dealing.In order to find the potential quality issues of the products,failure-mode effective analysis(FMEA)is used to screen out the key causes of low pass rate,and the key cause is identified and analyzed by presume inspection.SPC measurement,P control chart,exponentially weighted moving-average(EWMA)and process capability index(CP_K)are used to improve the quality of the key factor which affect pass rate,and Xbar-R is also used to monitor and verify the improvement measures after stable production.After using these improvement actions in the production and assembly process,the CP_K of key components increased from 0.64 to 1.03,the pass rate increased from60%to 95%;the assembly plant yield rate increased to 96%,which achieved the forecast goal.Through the research of this thesis,we can summarize the experience of SPC application and quality management,and extend to other enterprises,to contribute to the quality improvement,brand creation,transformation and upgrading of some small and medium-sized enterprises.