CUSUM control charts with variable sampling interval for monitoring the ratio of two normal variables. (17th December 2019)

• Record Type: Journal Article
• Authors: Nguyen, Huu Du; Tran, Kim Phuc; Heuchenne, Henri L.
• Is Part Of: Quality and reliability engineering international. Volume 36:Number 2(2020)
• Page Start: 474
• Page End: 497
• Publication Date: 2019-12-17
• Subjects: CUSUM -- Markov chain -- ratio distribution -- statistical process control -- VSI; Reliability (Engineering) -- Periodicals; Quality control -- Periodicals; High technology -- Periodicals; 620.00452
• DOI: 10.1002/qre.2595
• Languages: English
• ISSNs: 0748-8017

Abstract

Abstract: In many industrial manufacturing processes, the ratio between two normal random variables plays a key role in ensuring quality of products. Thus, monitoring this ratio is an important task that is well worth considering. In this paper, we combine a variable sampling interval (VSI) strategy with a cumulative sum (CUSUM) scheme to create a new type of control chart for purpose of tracking the ratio between two normal variables. The average time to signal ( A T S ) and the expected average time to signal ( E A T S ) criteria are used to evaluate the performance of the new VSI CUSUM RZ control chart. The numerical results show that the proposed control chart has much more attractive performance in comparison with the standard CUSUM‐RZ control chart and the VSI EWMA‐RZ control chart.