Properties and performance of one-sided cumulative count of conforming chart with parameter estimation in high-quality processes |
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| Authors: | Jing-Er Chiu Chih-Hsin Tsai |
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| Institution: | Department of Industrial Engineering and Management , National Yunlin University of Science and Technology , Yunlin , 64002 , Taiwan, ROC |
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| Abstract: | The one-sided cumulative count of conforming (CCC) chart is a useful method to monitor nonconforming fraction in high-quality manufacturing processes. The nonconforming fraction parameter is assumed to be known when implementing a one-sided CCC chart. In this study, we investigated the impact of estimated nonconforming fraction, pcirc] 0, in a one-sided CCC chart. The run length distribution is derived as well as the conditional probability of a false alarm rate (CFAR), conditional average run length (CARL) and its standard deviation (CSDRL). Simulation results are conducted to evaluate the effect of pcirc] 0 in a one-sided CCC chart. The results show that values of CFAR, CARL and CSDRL are close to the nominal values for a large sample. The impact of estimation errors was also studied. We find that CFAR decreases for large pcirc] 0. Thus, a large value of pcirc] 0 is suggested for fewer false alarms. |
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| Keywords: | one-sided design CCC chart high-quality process geometric distribution parameter estimation average run length |
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