The Design of the ARL‐Unbiased S2 Chart When the In‐Control Variance Is Estimated. (12th November 2013)

• Record Type: Journal Article
• Authors: Guo, Baocai; Wang, Bing Xing
• Is Part Of: Quality and reliability engineering international. Volume 31:Number 3(2015:Apr.)
• Page Start: 501
• Page End: 511
• Publication Date: 2013-11-12
• Subjects: process variance -- average run length -- S2 chart -- unbiased control chart; Reliability (Engineering) -- Periodicals; Quality control -- Periodicals; High technology -- Periodicals; 620.00452
• DOI: 10.1002/qre.1608
• Languages: English
• ISSNs: 0748-8017

Abstract

Abstract : The S 2 chart has been known as a powerful tool to monitor the variability of the normal process. When the variance of the process is unknown, it needs to be estimated by Phase I samples. It is well known that there are serious effects of parameter estimation on the performance of the S 2 chart based on known parameter assumption. If the effects of parameter estimation are not considered, it can lead to an increase in the number of false alarms and a reduction in the ability of the chart to detect process changes except for very small shifts in the variance. Based on the criterion of average run length (ARL) unbiased, a S 2 control chart is developed when the in‐control variance is estimated. The performance of the proposed control chart is also evaluated in terms of the ARL and standard deviation of the run length. Finally, an example is used to illustrate the proposed control chart. Copyright © 2013 John Wiley & Sons, Ltd.