CONFIDENCE INTERVALS AND SAMPLE SIZE DETERMINATION FOR C_pm

摘要

The capability index, C_pm sometimes called the Taguchi index, has the desirable characteristic of being sensitive to both dispersion and deviation of the process average from the engineering target. As a result, the proposed estimators of C_pm have a sampling distribution that is dependent on the non-central chi-square distribution. Hence, constructing confidence intervals, performing hypothesis testing or estimating sample size requirements necessitates manipulation of a rather complex functional expression, typically beyond the capabilities of practitioners who need readily available tools.