Economic optimization of acceptance interval in conformity assessment: 2. Process with unknown systematic effect

In this paper, optimization of acceptance interval in conformity assessment using the expression of the revenue that we showed in part 1 of this study is proposed under the condition of a systematic effect component being present in the measurement uncertainty. Systematic effect components are caused by unknown biases. Using the distribution based on the uncertainty information of the bias, we can develop the distribution of the revenue. Our idea is to set a percentile of the revenue distribution as the target of the maximization to reflect the systematic effect component in the optimization of the acceptance interval. We provide an equation for the optimum acceptance interval that can be numerically solved with little burden. We found that the choice of the probability for the percentile is an essential task in the optimization. Our proposed method incorporating the systematic effect seems to be sufficiently practical to be applied to actual processes.