전통적인 Demerit 관리도는 일반적으로 자동차, 컴퓨터, 핸드폰 등 하나의 복잡한 제품에서 다양한 유형의 결점들이 동시에 발생하는 공정을 모니터링하기 위하여 사용된다. 관리도에서 공정 평균의 작은 변동을 빠르게 감지하기 위한 방법으로 EWMA기법은 매우 효과적이다. 본 연구에서는 EWMA 기법 보다 공정 평균의 작은 변동에 더 좋은 성능을 보이는 GWMA기법과 전통적인 Demerit 관리도(1928)를 결합한 Demerit-GWMA(generally weighted moving average) 관리도를 제안하였으며 그 관리도의 수행도를 평가하였다. 그 수행도 평가 결과, Demerit-GWMA 관리도는 공정 평균의 작은 변동을 감지하는데 classical Demerit 관리도, Demerit-EWMA. 관리도에 비하여 더 민감하다.

When the production run is short and process parameters change frequently, it is difficult to monitor the process using traditional control charts. In such a case, the coefficient of variation (CV) is very useful for monitoring the process variability. Th

When the production run is short and process parameters change frequently, it is difficult to monitor the process using traditional control charts. In such a case, the coefficient of variation (CV) is very useful for monitoring the process variability. The CV control chart is an effective tool to control the mean and variability of process simultaneously. The CV control chart, however, is not sensitive at small shifts in the magnitude of CV. The CV-EWMA(exponentially weighted moving average) control chart which was developed recently is effective in detecting a small shifts of CV. Since the CV-EWMA control chart scheme can be viewed as a weighted average of all past and current CV values, it is very sensitive to small change of mean and variability of the process. In this paper, we propose an FIR(Fast initial response) CV-EWMA control chart to improve the sensitivity of a CV-EWMA scheme at process start-up or out-of-control process. Moreover, we suggest the values of design parameters and show the results of the performance study of FIR CV-EWMA control chart by the use of average run length( ). Also, we compared the performance of FIR CV-EWMA control chart with that of the CV-EWMA control chart and we found that the CV-EWMA control chart gives longer in-control ARL and much shorter out-of-control ARL.

Complex products may present more than one type of defects and these defects are not always of equal severity‘ These defects are class ified according to their seriousness and effect on product quality and performance. So, demerit systems are very effecti

Yield is a very important measure that can expresses simply for productivity and performance of company. So, yield is used widely in many industries nowadays. With the development of the information technology and online based real-time process monitoring

Complex Products may present more than one type of defects and these defects are not always of equal severity. These defects are classified according to their seriousness and effect on product quality and performance. Demerit systems are very effective sy

The control chart is widely used statistical process control(SPC) tool that searches for assignable cause of variation and detects any change of process. Generally, ？맴詠？ control chart and ？맴詠？ are most frequently used. When the production run is short and

  Ultra-high voltage transformer industry has characteristic of small quantity batch production system by other order processing unlike general mass production systems. In this industry, observance of time deadline is very important in market competitive

Recently we developed the eZ Six Sigma software for education of Hanyang University in 2004. This eZ Six Sigma software focused on educational parts. In this paper, we present introduction and Contents of this Software. This software will be helpful to improvement of Six Sigma educational environment.

In statistical process control applications, variable sample size (VSS) chart is often used to detect the assignable cause quickly. However, it is usually assumed that only one assignable cause results in the out-of-control in the process. In this paper,

Recently we developed the eZ Six Sigma software for education of Hanyang University in 2004. This eZ Six Sigma software focused on educational parts. In this paper, we present introduction and Contents of this Software. This software will be helpful to improvement of Six Sigma educational environment.

CUSUM control charts are widely used in process with small shifts since they have reasonable detection capability for small shifts. CUSUM control charts, however, are less effective in detection for recurring cycles or frequent small shifts in process. With Shewhart control charts, we have applied the variety of run rules to check the stability of process in addition to the situations that some points fall outside the control limits. In this paper, we propose the Z-CUSUM control chart.

Cusum control chart are widely used in process with small shifts. Because of cusum control chart has reasonable detection capability for small shifts. But Cusum control chart has unreasonable detection capability for recurring cycles or quickly change of small shifts. In Shewhart control charts with recurring cycles or quickly change of small shifts, when a point falls outside Shewhart control limits, the process is out of control. But, if assignable causes occur in process and the points falls inside its control limits, process can be considered in-control. For this situations, Shewhart control charts are used zones method ( ex＞ A, B, C ... ). ( We say ‘runs rules’ ) This paper investigated cumulative sum control chart for this some situations.

We developed the software named as Management Quality Renovation Software in 2002 as a government project supported by the Korean Standards Association. In this paper, we present our ways to help small and medium sized industries improve quality by Management Quality Renovation software.