A Confidence Interval Estimation Method for Process Capability Index with Bias

Abstract:

Process capability index (PCI) has been widely applied in manufacturing industry as an effective management tool for quality evaluation and improvement, whose calculation in most existing research work is premised on the assumption that there exists no bias. In this paper, the bias of gauge which exerts an effect on the calculation of PCI is indicated inevitable. The influence on PCI caused by the bias is analyzed by constructing a comparative ratio R between the empirical process capability index and the PCI. A confidence interval estimation method is proposed to solve the underestimation problem of PCI.

• Periodical: Advanced Materials Research (Volume 1039)
• Pages: 622-626
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1039.622
• Online since: October 2014
• Authors: Zai Fang Zhang, Xiao Song Wu, Rui Miao, Bei Xin Xia*
• Keywords: Bias, Confidence Interval Estimation, Process Capability Index

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