원문정보
초록
영어
In a multivariate normal production process Np(μ, ∑), a chart combining three EWMA charts with accumulate-combine method for μ , variance components of ∑ , and off-diagonal elements of ∑ , into a EWMA (exponentially weighted moving average) chart is considered, which is called a combined EWMA chart. Through simulation work, the proposed combined EWMA chart’s numerical performance and properties are examined. The simulation results show that the proposed combined EWMA chart, which is simultaneously monitoring all the process parameters of multivariate normal production process, works effectively in the perspective of means, variances and correlation coefficients. In addition, the combined EWMA chart is extended to VSI chart.
목차
1. Introduction
2. Control Statistic for Multivariate Normal Process with Accumulate-Combine Method
2.1 Control Statistic for μ
2.2 Control Statistic for Variances in ∑
2.3 Control Statistic for CorrelationCoefficients in Σ
3. Combined Control Chart and Types of Shifts
4. Numerical Performances and Concluding Remarks
References