Effect of measurement errors on the VSI (X)over-bar chart

摘要

Measurement errors often exist in quality control applications. In this paper, the performance of the variable sampling interval (VSI) (X) over bar chart is investigated when measurement errors exist using a linearly covariate error model. It is shown that the performance of the VSI (X) over bar chart is significantly affected by the presence of measurement errors. The effect of taking multiple measurements, for each item in a subgroup, on the performance of VSI (X) over bar chart is also investigated in this paper. An example is provided in order to illustrate the application of the VSI (X) over bar chart with measurement errors.