An X and EWMA chart for individual observations An X and EWMA Chart for Individual Observations SUSAN L.ALBIN and LAN KANG Rutgers,The State University of New Jersey.Piscataway.NJ08855 GERALD SHEA Erron Research and Engineering Company.Florham Park,NJ07932 in that both insinge.easily interpreted graph. small shifts in the process mean and large shifts in the process standard deviati Introduction trol ae many indstrial situations where it does not make snse to periodically collect a sampl control cha in the rts:the mple. (19))However.in these texts and elsewhere be Individual observation control charts are ofter carecoineg used to monitor chemical processes where.for ex ponentia average (EV IA)cha can use combinations of these charts and run rules. y.Keats.Bo While there is a wealth of knowledge the al ternatives for monitoring processes with individual unit is measured.They are also cost of measuire of charts andrun rues is most practical and use Dr.Albin is a Pr combinations of the X chart,MR chart.EWMA ring Associate.He is a Member of e-alarm.We als Vol.29.No.1.January 1997 41 Journal of Quality Technology Reproduced with permission of the copyright owner.Further reproduction prohibited without permissionReproduced with permission of the copyright owner. Further reproduction prohibited without permission. An X and EWMA chart for individual observations Albin, Susan L; Kang, Lan; Shea, Gerald Journal of Quality Technology; Jan 1997; 29, 1; ABI/INFORM Global pg. 41