Controlling high quality manufacturing processes: a robustness study of the lower-sided tbe ewma procedure

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2008
Pehlivan, Canan
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In quality control applications, Time-Between-Events (TBE) type observations may be monitored by using Exponentially Weighted Moving Average (EWMA) control charts. A widely accepted model for the TBE processes is the exponential distribution, and hence TBE EWMA charts are designed under this assumption. Nevertheless, practical applications do not always conform to the theory and it is common that the observations do not fit the exponential model. Therefore, control charts that are robust to departures from the assumed distribution are desirable in practice. In this thesis, robustness of the lower-sided TBE EWMA charts to the assumption of exponentially distributed observations has been investigated. Weibull and lognormal distributions are considered in order to represent the departures from the assumed exponential model and Markov Chain approach is utilized for evaluating the performance of the chart. By analyzing the performance results, design settings are suggested in order to achieve robust lower-sided TBE EWMA charts.
Industrial engineering.
http://etd.lib.metu.edu.tr/upload/12609937/index.pdf
https://hdl.handle.net/11511/17912
Graduate School of Natural and Applied Sciences, Thesis

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Citation Formats
C. Pehlivan, “Controlling high quality manufacturing processes: a robustness study of the lower-sided tbe ewma procedure,” M.S. - Master of Science, Middle East Technical University, 2008.
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