D.C.MONTGOMERY.J.B.KEATS.G.C.RUNGER,AND W.S.MESSINA TABLE4.Averag Run Lenths for the Rules in Table3.Standard Deviations f the Run th are Given in Parenthesis Mo Trend EPC and EPC and EPC and EWMA EWMA CUSUM 入=0.1 入=0.4 h=5k=0.5 0.05 119.9 119.8 149.2 (1.61) (1.23) (1.47 0.10 109.7 73.5 109.2 1.39 (0.70) (1.06) 0.25 60.8 33.9 (0.68) (0.30) 62品 0.50 32.1 17.4 24.2 (0.36) (0.15) (0.24 1.00 14.3 9.1 10.0 (0.17 (0.07） (0.09) Summary mical and s plants and in computer inte- desirable results.EP an important too to ons fom to that o provement procese of the s itself,and Acknowledgment an be used to identify and subsequently eliminate and su s and the Editor for aps a n References ,O.D.(1976).Time Series and Forecasting.But- We described and illustrated a simple ndo Gregor Box,G.E (1990)model of the erim nt we shov a p cal Pr es certain e ernal assignable causes.Bot h sus tained shifts and nds SPC o: me Theory of Sampling.John Wi- mo ation fro in a system ey &Sons,New York,NY. MIT Center for engin eering)control is a simple but highly effective way to integrate thes Minc,W.E.(13).The We conclude that prope for LTIN,F.W.;HARN,G.J.;and TUCKER,W.T.(1989 The contro at the ASQC Fall Technical Con models,including proportional-integra -diferent erence,Ho ston,TX (PID)contr (see K NTER, aga (19 f Ou y18 ,pp.203-210, fective.We concluded tha in many HUNTER,J.S.(198)."A Point-Plot Equ nt to the Joural of Quality Technology Vol.26,No.2,April 1994