No study to date has used laboratory critical values to evaluate variations in patient adverse events. We retrospectively analyzed a database of critical values to determine their distribution by hospital unit over time. The data were drawn from the Ohio State University Medical Center Information Warehouse (Columbus) for a 58-month period. Critical values were plotted over time on statistical ...

Designs of the double sampling (DS) X chart are traditionally based on the average run length (ARL) criterion. However, the shape of the run length distribution changes with the process mean shifts, ranging from highly skewed when the process is in-control to almost symmetric when the mean shift is large. Therefore, we show that the ARL is a complicated performance measure and that the median r...

A memory-type control chart is an important tool of statistical process for monitoring small to moderate shifts in the manufacturing process. Using prior information by Bayesian approach helpful charts. In this paper, a new hybrid exponentially weighted moving average (HEWMA) suggested under theory using ranked set sampling (RSS) schemes posterior and predictive distribution with informative di...

The Multivariate EWMA control chart, MEWMA, Lowry, Woodall, Champ and Ridgon [1] and its univariate version EWMA, may be designed to efficiently detect small shifts in the mean vector of a set of p quality characteristics of a production process. However, this work presents a method for the optimal design of MEWMA and EWMA charts parameters to control processes where it is not convenient to det...

Abstract:
 In many real-world applications, the data to be used in a control charting method are not crisp since they approximated due environmental uncertainties, these situations, fuzzy numbers and linguistic variables grab such uncertainties. That is why use of chart, which used, justified. As an exponentially weighted moving average (EWMA) scheme usually detect small shifts, this paper ...

Disease monitoring and surveillance play a crucial role in control and eradication programs, as it is important to track implemented strategies in order to reduce and/or eliminate a specific disease. The objectives of this study were to assess the performance of different statistical monitoring methods for endemic disease control program scenarios, and to explore what impact of variation (noise...