In various industrial contexts, there is a need for online monitoring of quality characteristics represented as the ratio of two normal random variables. This includes scenarios such as maintaining the correct proportion between ingredients or elements in a product, assessing product performance before and after specific operations like chemical reactions, and monitoring chemical or physical properties computed as ratios. This paper introduces two new Phase II Shewhart monitoring schemes for monitoring the ratio of population means of bivariate normal distributions when parameters are known and unknown, respectively. Notably, the size of each sample unit can vary across different subgroups, enhancing the adaptability of the chart implementation in diverse manufacturing settings. We use the average run length (ARL) for evaluating the Phase II performance of the proposed monitoring schemes. Simulation results are provided to demonstrate the statistical performance of the investigated monitoring schemes under the known and unknown parameter cases. Two real‐data examples are presented for illustration.
The shifted (or two‐parameter) exponential distribution is a well‐known flexible probability model for skewed data, such as failure times or survival times due to its two‐parameter representation. Control charts for monitoring a process that is modeled according to a shifted exponential distribution have been studied...
D. Antzoulakos, K. G. Fountoukidis, A. Rakitzis· Quality and Reliability Engi...· 0 citations
This study presents a new cumulative quantity control chart, called the Generalized Rayleigh cumulative quantity control chart (
GRCQC
-chart), that can be used for monitoring time between events (TBE) data in high-yield manufacturing processes. It uses the inverse cumulative distribution function of Generalized Ra...
Zaheer Ahmed, Muhammad Aslam, Emad Alyan et al.· Frontiers in Applied Mathema...· 0 citations
This paper addresses the critical challenge of monitoring process location and scale parameters when the underlying distribution is unknown and the magnitude of potential shifts is unspecified. We propose a new Distribution‐Free Double Smoothing Exponentially Weighted Moving Average (DDSE) scheme, which incorporates...
An-An Tang, Fan Dong, Yuan-Man Ma et al.· Quality and Reliability Engi...· 0 citations
Monitoring the ratio of two normally distributed quality characteristics is important in a range of industrial applications. This study quantifies the effect of measurement error on two one‐sided Synthetic‐RZ charts for detecting downward and upward shifts in that ratio. The proposed framework combines a correlated l...
K. D. Tran, T. Nguyen, Kim Phuc Tran· Quality and Reliability Engi...· 0 citations
In this research, an attribute control chart is developed in order to monitor the product lifetimes having odd exponential half‐logistic distribution (OEHLD) with truncated life tests. The novelty of the suggested scheme is in truncation time that is assumed to be a multiple of the median of lifetime distribution ins...
M. Ali, Nasrullah Khan, M. Aslam· Quality and Reliability Engi...· 0 citations
Statistical modeling of lifetime and reliability data has gained significant interest in the last few decades because of its potential use in various disciplines, including engineering, biomedical sciences, agriculture, and medicine. For portraying complex data behaviors, especially when the hazard rate demonstrates no...
Chainarong Kesamoon, W. Panichkitkosolkul· Science and Technology Indon...· 0 citations
We use cookies to run the site and, with your consent, for analytics and to show ads.
See our Cookie Policy.
