TY - JOUR
T1 - Optimal T2 Control Chart with a Double Sampling Scheme - An Alternative to the MEWMA Chart
AU - Faraz, Alireza
PY - 2012/11
Y1 - 2012/11
N2 - Recent studies have shown that a double sampling (DS) scheme yields improvements in detection times of process shifts over variable ratio sampling (VRS) methods that have been extensively studied in the literature. Additionally, a DS scheme is more practical than some of the VRS methods since the sampling interval is fixed. In this paper, we investigate the effect of double sampling on cost, a criterion as important as detection rate. We study economic statistical design of the DS T 2 chart (ESD DS T 2) so that designs are found that are economically optimal but yet meet desired statistical properties such as having low probabilities of false searches and high probabilities of rapid detection of process shifts. Through an illustrative example, we show that relatively large benefits can be achieved in a comparison with the classical T 2 chart and the statistical DS T 2 charts with our ESD DS T 2 approach. Furthermore, the economic performance of the ESD DS T 2 charts is favorably compared to the MEWMA and other VRS T 2 control charts in the literature.
AB - Recent studies have shown that a double sampling (DS) scheme yields improvements in detection times of process shifts over variable ratio sampling (VRS) methods that have been extensively studied in the literature. Additionally, a DS scheme is more practical than some of the VRS methods since the sampling interval is fixed. In this paper, we investigate the effect of double sampling on cost, a criterion as important as detection rate. We study economic statistical design of the DS T 2 chart (ESD DS T 2) so that designs are found that are economically optimal but yet meet desired statistical properties such as having low probabilities of false searches and high probabilities of rapid detection of process shifts. Through an illustrative example, we show that relatively large benefits can be achieved in a comparison with the classical T 2 chart and the statistical DS T 2 charts with our ESD DS T 2 approach. Furthermore, the economic performance of the ESD DS T 2 charts is favorably compared to the MEWMA and other VRS T 2 control charts in the literature.
KW - Hotelling's T control chart
KW - MEWMA
KW - double sampling (DS)
KW - economic statistical design (ESD)
KW - genetic algorithm (GA)
UR - http://www.scopus.com/inward/record.url?scp=84867900942&partnerID=8YFLogxK
U2 - 10.1002/qre.1268
DO - 10.1002/qre.1268
M3 - Article
SN - 0748-8017
VL - 28
SP - 751
EP - 760
JO - Quality and Reliability Engineering International
JF - Quality and Reliability Engineering International
IS - 7
ER -