A variable sampling interval EWMA t chart with auxiliary information – A robustness study in the presence of estimation error
| Autor: | Ming Ha Lee, Michael B. C. Khoo, Peh Sang Ng, Sajal Saha |
|---|---|
| Rok vydání: | 2022 |
| Předmět: |
General Engineering
Process (computing) Sampling (statistics) Interval (mathematics) Variable sampling Engineering (General). Civil engineering (General) Auxiliary information Average time to signal Standard deviation Exponentially weighted moving average t chart Chart Robustness (computer science) Statistics Variable sampling interval Expected average time to signal EWMA chart TA1-2040 Mathematics |
| Zdroj: | Alexandria Engineering Journal, Vol 61, Iss 8, Pp 6043-6059 (2022) |
| ISSN: | 1110-0168 |
| DOI: | 10.1016/j.aej.2021.11.033 |
| Popis: | This article proposes the variable sampling interval (VSI) exponentially weighted moving average (EWMA) t chart for the process mean using auxiliary information (AI) (denoted as the VSI EWMA t-AI chart). The proposed chart allows different sampling intervals to be adopted based on prior process quality. The average time to signal (ATS) and expected average time to signal (EATS) criteria are used to evaluate the performance of the proposed chart. Numerical analyses are conducted and the results show that the proposed VSI EWMA t-AI chart surpasses the EWMA t-AI chart in the detection of all sizes of shifts in the process mean when there are no changes (or estimation error) in the process standard deviation. Additionally, the proposed VSI EWMA t-AI chart is found to be more robust than the VSI EWMA X ¯ -AI chart when there are changes in the process standard deviation. |
| Databáze: | OpenAIRE |
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