Control charts are generally used for process control, but the role of traditional control charts have been limited in case of a non-contaminated process. Traditional x-s control chart has not been activated well for such a problem because of trying to control processes as center line and control limits changed by the contaminated value. This paper suggests modified x-s control chart based on robust estimation. In this paper, we consider the trimmed mean of the sample means and the trimmed mean of the sample standard deviations. By comparing with ARL value, the responding results are decided. The comparison resultant results of traditional control chart and modified control chart are contrasted.

1. 서 론
 2. 이론적 배경
  2.1 Shewhart의 3σ법 관리도
  2.2 로버스트 추정치
 3. 수정된 x-s 관리도의 설계
 4. 실험 및 분석
  4.1 공정변화 설계
  4.2 수치 예
 5. 결 론
 Acknowledgement
 References
 ORCID

• 정영배(인천대학교 산업경영공학과) | Young-Bae Chung Corresponding Author
• 김연수(인천대학교 산업경영공학과) | Yon-Soo Kim