Research On The Application Of PCI Theory In The Production Of QS Welding Machine

At present, with the development of the real economy, customer demand for products become more and more strict, how to gain a foothold in the fierce market competition has been the problem of QS company. This article focuses on the quality control of welding machine production in QS company.The analysis of process capability index (PCI) is very important in the process of quality control of production. In general, the output of the process is assumed to be normally distributed, but the non normal distribution is found everywhere in reality. The study of process capability index under non normal condition has important significance for the quality control of the actual production. Through in-depth study, we can enrich the theoretical knowledge of process capability index, and can play a certain guiding significance for QS company.Through in-depth understanding of QS's mode of production, this paper does research on the quality control of multi varieties and small batch production mode, focus on the process capability index of multi varieties and small batch production mode calculation method, in order to achieve better quality control.This article from two aspects. On the one hand, it is from the non normal direction. On the basis of fully understanding the related theory of process capability, the calculation methods of five kinds of non normal process capability indices are compared. Then, by using the Monte Carlo method, combined with the above method, select the lognormal distribution and Weibull distribution data for statistical analysis. Finally, the Matlab program is written to simulate the settlement, and get the results: in the actual application process due to the restrictions of many factors, it is more desirable to use the partial state process capability index Cs method.On the other hand, the quality control of multi varieties and small batches is mainly studied. In view of the limitation of traditional statistical process control, the Bootstrap correlation method is proposed, and the process capability index and its confidence interval calculation based on Bootstrap correlation method are mainly studied. This part is also based on Matlab programming, the different distribution of different sample size, data analysis and comparison, the conclusions are as follows: t percentile Bootstrap (Percentile-t Bootstrap PTB) method than the other two methods in the treatment of many varieties of small batch of more advantages, process the ability index of the estimated value and the confidence interval is more accurate.Finally, combining the skewness of process capability index Cs and t percentile Bootstrap method, and the use of actual production in QS welding, good application. At the same time, the paper puts forward the general flow of the process capability analysis of QS company. The proposed process will play a guiding role in the production of QS company.