The Korean Journal of Applied Statistics (응용통계연구)

The Korean Statistical Society (한국통계학회)
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A Control Chart Method Using Quartiles for Asymmetric Distributed Processes

비대칭 분포를 따르는 공정에서 사분위수를 이용한 관리도법

  • Park Sung-Hyun (Department of Statistics, Seoul National University) ;
  • Park Hee-Jin (Department of Statistics, Seoul National University)
  • Published : 2006.03.01
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Abstract

This paper proposes a simple control chart method which can be practically used for asymmetric process data where the distribution is unknown. If we use the Shewhart type control charts which are based on normality assumption for the asymmetric process data, the type I error could increase as the asymmetry increases and the effectiveness of control chart to control variation decreases. To solve such problems, this paper suggests to calculate the control limits based on the quartiles. If we obtain the control limits by such quartile method, the type I error could decrease and it looks much more practical for asymmetric distributed process data.

본 연구에서는 분포를 알 수 없고 비대칭인 공정자료에 실용적으로 적용할 수 있는 간단한 관리도법을 제안하였다. 비대칭 분포를 따르는 공정자료에 정규성 가정에 기초한 슈하르트 관리도를 그대로 적용하면 비대칭성이 증가할수록 제 1종 오류를 범할 확률이 증가할 가능성이 높아지며 변동을 관리하는데 효율성이 떨어지게 된다. 이러한 문제를 해결하기 위해 본 연구에서 제시한 관리도는 관리한계선을 사분위수에 기초하여 정하는 방안을 제시하고 있다. 이러한 방법으로 관리한계선을 그릴 경우 제 1종 오류도 감소하게 되고, 비대칭분포를 하는 공정자료에 대하여 매우 실용적이라고 하겠다.

Keywords

References

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