The Studey Of Statistical Process Control In Multi-Specification & Small-Batch Production

Quality Control is an important aspect in Quality Management. It means the job technology and activities adopted to achieve the quality request and aims to inspect the process, find and eliminate the problems of every phase. It carries through the principle of prevention to assure product quality and economic benefit. Statistical Process Control (SPC) is the important method of Quality Control, and Control Chart is the critical technology of SPC. Because the traditional Control Chart brought in Mass Production and rigid production environment can hardly be applied in small-batch production. As the popularization of traditional Control Chart, how to apply the SPC method and make the classical Quality Control technology into the individual production means a lot.The character of small-batch production is lack of data and product quality information, and we cannot adopt the conventional control method. So there is a necessity to study the Quality Control in small-batch production and put forward a more efficient method. Following is the main contents of this paper:Firstly, point out the importance of Quality Control in nowaday society and look back the evolution of Quality Control and Quality Control method; introduce the produce, progress, meanings and essential of SPC, and make emphases on the study and development of SPC in multi-specification and small-batch production home and abroad.Secondly, introduce the theory basis of SPC, which includes the probability statistics of normal distribution and the basic knowledge of t distribution.Thirdly, introduce the basic theory of Control Chart, which includes the produce of Control Chart, the function of Control Chart, and point out how to use Control Chart to judge whether the process is in stabilization or not.Fourthly, analyze the disadvantage of traditional mean Control Chart in small-batch production condition, and by constructing unitary normal linear model, the mathematical models for the unitary Quality Control characteristics are established. Fifthly, point out the meaning of multivariate Quality Control study, and by constructing multi-normal linear model, the mathematical models for the multivariate Quality Control characteristics are established.