Since The Control Chart Theory And Its Applications

The purpose of the statistical process control is to build and maintain the process atan acceptable and stable level, and to ensure that products and services meet therequirements. To achieve this, the main statistical tool is the control chart. A basicassumption of conventional control charts is that observations from the process atdifferent times are independent random variables. But in fact many processes displayinherently auto correlated behavior. As a result, using conventional control charts for asmooth autocorrelation process, there will be false alarms. The process will make a wrongjudgment. The quality management and quality control will be seriously misled, and theeffect of control charts will be diminished, or even the process will be out of control. Thepaper systematically studied the theory of conventional and auto-correlated control chart, and in order to show the influence of auto-correlated phenomenon on the quality control, various related process control charts are analyzed. Using residual chart, theauto-correlated economic time-series is analyzed, and the early warning of futureeconomic running quality is carried on.The main content of this paper is as follows:The first chapter expounds the purpose of this paper, and introduces the history ofthe control chart and the latest developments.The second chapter systematically introduces the principle, design, classification, and abnormality criteria of the control chart.The third chapter introduces three conventional control charts: mean (?) and range(R) chart, individual (X) and moving range (R_s) chart, exponentially weighted movingaverage (EWMA) control chart.The fourth chapter introduces two auto-correlated control charts: residual chart, improved exponentially weighted moving average control chart.The fifth chapter contrasts the application of different control charts in auto-correlated process.The sixth chapter uses residual control chart to monitor the GDP of China from 1952to 2004; and judges the performance of macroeconomic and forecasts it for the future.The seventh chapter summarizes the full paper and proposes the further researchwork.