| Statistical process control is a theory technique of using statistical methods tomonitor the production process. Its core idea is prevention and the most important tool isthe control chart. Through anglicizing and tracing to the inspection data in the productionprocess to distinguish normal and abnormal fluctuations, in order to timely warning toreducing defection, and to improve production efficiency. But the traditional qualitycontrol chart can not satisfy the needs of corporate diversity. To improve the efficiency andeffectiveness of controls, it is required to improve the control chart. This paper introducesthe conventional control charts, dynamic control charts, control charts with warning limitsand do further research based on the variable sampling interval control charts and variablesample size. Its main results are as follows:First, the paper improved mean control chart with warning limits based on theexisting dynamic control charts and designed variable sampling intervals mean controlchart with warning limits. It gave the average chain length of the algorithm, and calculatedthe average time to signal. Comparing with conventional control charts and other controlchart, the improved control chart has a higher efficiency.Secondly, the paper described variable sampling intervals median control chart withwarning limits and compared with the corresponding conventional control charts. Theresults show that the average time to signal of variable sampling interval control charts isshorter. And the efficiency of the mean control chart is lower than median control chartFinally, the paper constructs the mean control chart with variable sample size andsampling interval, using the average time to signal to measure the efficiency of the controlchart, and comparing with the conventional control charts, control charts with variablesampling intervals and variable control chart compares the sample size, it is proofed thatvariable control with two parameters is more effective. |
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