Comparison for the Economic Performance of Control Charts with the VSI and VSS Features

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Journal of Korean Society for Quality Management > Volume 30(2); 2002 > Article

Journal of Korean Society for Quality Management 2002;30(2): 99-.

VSI와 VSS 관리도의 경제적 효율 비교

박창순¹, 이재헌², 김영일³

¹중앙대학교 응용통계학과
²광주대학교 산업정보공학과
³중앙대학교 정보시스템학과

Comparison for the Economic Performance of Control Charts with the VSI and VSS Features

ABSTRACT

Variable sampling interval(VSI) and variable sample size(VSS) control charts vary the sampling rate for the next sample depending on the current chart statistic. This paper develops EWMA charts with the VSI and VSS features, and investigates the effectiveness of these charts in context of an economic model. The economic properties of these charts are evaluated by using Markov chain methods. The model contains cost parameters which allow the specification of the costs associated with sampling, false alarms, and operating off target. This economic model can be used to quantify the cost saving that can be obtained by using control charts with the VSI and VSS features instead of with the fixed sampling rate(FSR) feature, and can also be used to gain insight into the way that control charts with the VSI and VSS features should be designed to achieve optimal economic performance. The economic performance of X charts with the VSI and VSS features is also considered

Key Words: VSI;VSS;VSR;Economic Design;Markov Chain;