두 가지 복합 이상원인 영향이 있는 공정에 대한 VSS Xbar 관리도의 경제적 설계

Abstract

In statistical process control applications, variable sample size(VSS) X bar chart is often used detect the assignable quickly.However, it is usually assumed that only one assignable cause results in the out-of-control in the process. In this paper, we propose the algorithm to minimize the function of cost per unit time and compare the economic design and the statistical design by use of the value of cost per unit time. We consider double assgnable causes to occur with compound in the process and adopt the Markov chain approach to investigate the statistical properties of VSS X bar chart. A procedure that can calculate the control chart`s parameters is proposed by the economic design.