Statistically constrained economic design of the EWMA control chart

Douglas Montgomery, James C C Torng, Jeffery K. Cochran, Frederick P. Lawrence

Research output: Contribution to journalArticle

80 Citations (Scopus)

Abstract

This paper presents a statistically constrained economic model for the optimal design of an exponentially weighted moving average (EWMA) control chart for controlling process means. The optimum design parameters include the sample size, control limit width, sampling interval, and EWMA weight. The parameters are obtained by minimizing a total cost function proposed by Lorenzen and Vance, subject to additional statistical constraints on average run length (ARL) or average time-to-signal (ATS). Sensitivity analysis of the minimum costs as they are affected by various ATS bounds shows that the cost is more sensitive to smaller out-of-control bounds on ATS or ARL, but relatively insensitive to larger bounds. Investigation of economic statistical design for the EWMA chart reveals that adding constraints does not significantly increase the cost and does provide better protection against shift sizes other than those expected. Cost comparisons between optimal economic designs and optimal economic statistical designs show no significant cost increase when imposing statistical constraints on the cost model.

Original languageEnglish (US)
Pages (from-to)250-256
Number of pages7
JournalJournal of Quality Technology
Volume27
Issue number3
StatePublished - Jul 1995

Fingerprint

Exponentially Weighted Moving Average Control Chart
Economic Design
Average Time to Signal
Economics
Costs
Exponentially Weighted Moving Average
Average Run Length
Process Mean
Economic Model
Cost Model
Chart
Sensitivity Analysis
Cost Function
Sample Size
Cost functions
Sensitivity analysis
Control charts
Exponentially weighted moving average
Economic design
Interval

ASJC Scopus subject areas

  • Management Science and Operations Research
  • Industrial and Manufacturing Engineering
  • Statistics and Probability

Cite this

Montgomery, D., Torng, J. C. C., Cochran, J. K., & Lawrence, F. P. (1995). Statistically constrained economic design of the EWMA control chart. Journal of Quality Technology, 27(3), 250-256.

Statistically constrained economic design of the EWMA control chart. / Montgomery, Douglas; Torng, James C C; Cochran, Jeffery K.; Lawrence, Frederick P.

In: Journal of Quality Technology, Vol. 27, No. 3, 07.1995, p. 250-256.

Research output: Contribution to journalArticle

Montgomery, D, Torng, JCC, Cochran, JK & Lawrence, FP 1995, 'Statistically constrained economic design of the EWMA control chart', Journal of Quality Technology, vol. 27, no. 3, pp. 250-256.
Montgomery, Douglas ; Torng, James C C ; Cochran, Jeffery K. ; Lawrence, Frederick P. / Statistically constrained economic design of the EWMA control chart. In: Journal of Quality Technology. 1995 ; Vol. 27, No. 3. pp. 250-256.
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