Answers are grounded in this paper and cite their sources.
A modified Shewhart-exponentially weighted moving average X-bar statistical control scheme is evaluated. It is characterized by the use of a Shewhart component requiring two (or more) plotted points beyond reduced width (i.e., less than three-sigma) control limits to give an out-of-control signal. Schemes with both better average run length profiles and better early false-signal characteristics than those associated with standard Shewhart-runs rules schemes are suggested.
No takes yet. Share an insight, caveat, or question.
Morton Klein (1997) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: