The traditional control charts have a problem that a control limits are placed to depend on the accuracy of estimate of parameters. This problem caused high false alarm rate. In this paper, we review the uncertainty of control limits and propose the methods which have more reliable control limits using a coefficient of variance. Further more, we present a efficient methods that can control a different type of quality characteristics at the same time. The Weibull distribution is used to modeling the control chart. This type control chart may be useful tools in the short production runs.

ABSTRACT 
1. 서론 
2. 변동계수(CV)의 특성 
3. CV를 이용한 변동의 비교 
4. CV-chart 의 설계 
5. 와이블 분포의 모수 추정 
6. 관리도의 적용 
7. 수행도 평가 
8. 결론 
참고문헌

• 이만식 | Yi Man Sic
• 강창욱 | Kang Chang Wook