A Bootstrap Confidence Limit for Process Capability Indices
نویسنده
چکیده
The process capability indices are widely used by quality professionals as an estimate of process capability. The lower confidence limits of PCIs are difficult to be estimated by parametric methods for some non-normal distributed processes. The non-parametric but computer intensive Bootstrap techniques are utilized for these cases. The Percentile-t Bootstrap (PTB) method is used to estimate the confidence interval for PCIs of these non-normal distributed processes in the paper. A series of simulations using different distributions, parameters and sample size for the index Cpk was undertaken to compare the performance and reliability of PTB to SB, PB and BCPB. The results show that the PTB method is better to estimate lower confidence limits of PCIs for most non-normal distributed processes.
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