05227189

j

05227189 Fournier, B. Rupin, N. Bigerelle, M. Najjar, D. Iost, A. Comments on the mixture detection rule used in SPC control charts. Commun. Stat., Simulation Comput. 36, No. 6, 1321-1331 (2007). 2007 Taylor \& Francis, Philadelphia, PA EN average run length mixture statistical process control test for special causes type-I error Western electric rules

doi:10.1080/03610910701569630

Summary: When calculating independently the false alarm rate of the eight usual runs rules used in statistical process control (SPC) charts, it appears that the proposed rule designed to detect mixture patterns corresponds to a Type-I error strongly lower than the seven other rules. This discrepancy is underlined and the mixture rule is shown to be useless both for in-control and out-of-control processes. Thus a modification of the mixture detection rule is proposed and the impact of this new mixture rule is then illustrated and discussed using Monte Carlo calculations.