Average Run Lengths of EWMA Control Charts for Monitoring a Process Standard Deviation

Abstract

AbstractA program is presented that generates a table of ARL's for a one-sided EWMA control chart on a process standard deviation. The combination of smoothing parameter λ and constant upper control limit multiplier K that produces the minimum ARL for a specified increase in the standard deviation can be determined from that table. Additional informationNotes on contributorsMarc D. HamiltonMr. Hamilton is a Consultant in the Manufacturing Management Division.Stephen V. CrowderDr. Crowder is a Senior Member of the Technical Staff in the Statistics, Computing, and Human Factors Division.