A manufacturing process cannot be released to production until it has been proven to be stable. Also, we cannot begin to talk about process capability until we have demonstrated stability in our process. This means that the process variation is the result of random causes only and all assignable or special causes have been removed. In complicated manufacturing processes, such as drilling proces...

Some quality control schemes have been developed when several related quality characteristics are to be monitored. The familiar multivariate process monitoring and control procedure is the Hotelling’s T 2 control chart for monitoring the mean vector of the process. It is a direct analog of the univariate shewhart x̄ chart. As in the case of univariate, the ARL improvements are very important par...

Lindley distribution is a continuous with various applications some of which are in medicine, genetics, epidemiology, biology, finance and actuarial sciences, ecology, meteorology, sociology, demography, agriculture, hydrology, geosciences, reliability engineering, life testing survival analysis, airborne systems communications, environmental studies modeling describing human mistakes, strikes,...

We propose a new multivariate CUSUM control chart, which is based on selfadaption of its reference value according to the information of current process readings, to quickly detect the multivariate process mean shifts. By specifying the minimum magnitude of the process mean shift in terms of its non-centrality parameter, our proposed control chart can achieve an overall performance for detectin...

Background. Statistical process control (SPC) can be an effective complement to healthcare-associated infection (HAI) surveillance. Since this use of SPC somewhat differs from its manufacturing origins, some issues warrant exploration to maximize SPC’s value in detecting outbreaks and reducing HAIs. Little empirical investigation has been conducted to develop a framework for managing signals fr...

The exponentially weighted moving average (EWMA) control chart is a memory-type known to be more efficient in detecting small and moderate shifts the process parameter. double EWMA (DEWMA) an extension of that effective than latter detection small-to-moderate shifts. This paper proposes new distribution-free (or nonparametric) triple (TEWMA) based on Wilcoxon rank-sum (W) statistic improve abil...

BACKGROUND Comparison of outcomes requires adequate risk adjustment for differences in patient risk and the type of intervention performed. Both unintentional and intentional misclassification (also called gaming) of risk factors might lead to incorrect benchmark results. Therefore, misclassification of risk factors should be detected. We investigated the use of statistical process control tech...

although control charts are very common to monitoring process changes, they usually do not indicate the real time of the changes. identifying the real time of the process changes is known as change-point estimation problem. there are a number of change point models in the literature however most of the existing approaches are dedicated to normal processes. in this paper we propose a novel appro...