Control charts are themost extensively used technique to detect the presence of special cause variations in processes. They can be classified intomemory andmemoryless control charts. Cumulative sum and exponentially weightedmoving average control charts are memory-type control charts as their control structures are developed in such a way that the past information is not ignored as it is done i...

In this article, a novel acceptance-sampling plan is proposed to decide whether to accept or reject a receiving batch of items. In this plan, the items in the receiving batch are inspected until a nonconforming item is found. When the sum of two consecutive values of the number of conforming items between two successive nonconforming items falls underneath of a lower control threshold, the batc...

Correlated binary data are encountered in many areas of medical research, system reliability and quality control. For monitoring failures rates in such situations, simultaneous bivariate cumulative sum (CUSUM) charts with the addition of secondary control limits are proposed. Using an approach based on a Markov chain model, the run length properties of such a monitoring scheme can be determined...

In this paper, we first propose a maximum likelihood estimator (MLE) of a change point in highyield processes, where the only assumption is that the change belongs to a family of monotonic changes. Following a signal from the cumulative count of conforming (CCC) control chart, the performance of the proposed monotonic change-point estimator is next evaluated by comparing its performances to the...

usually, in monitoring schemes the nominal value of the process parameter is assumed known. however, this assumption is violated owing to costly sampling and lack of data particularly in healthcare systems. on the other hand, applying a fixed control limit for the risk-adjusted bernoulli chart causes to a variable in-control average run length performance for patient populations with dissimilar...

OBJECTIVE This study aims to compare different control charts to monitor the nosocomial infection rate per 1,000 patient-days. METHODS The control charts considered in this study were the traditional Shewhart chart and a variation of this, the Cumulative Sum and Exponentially Weighted Moving Average charts. RESULTS We evaluated 238 nosocomial infections that were registered in the intensive...

The purpose of this article is to present an optimization model for designing an acceptance sampling plan based on cumulative sum of run length of conforming items. The objective is to minimize the total loss including both the producer and consumer losses. The concept of minimum angle method is applied to consider producer and consumer risks in the optimization model. Also the average number o...