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 paper, we develop a process control approach to detect linear trends in the process mean. A statistic based on the deviation between the target mean and the expected mean of the process is used in the development of the new approach. The statistic is shown to have a Chi-square distribution. The approach is described and its performance is compared with Cumulative Sum (CUSUM), Exponentia...

Control charts are widely used for process monitoring. They show whether the variation is due to common causes or whether some of the variation is due to special causes. To detect large shifts in the process, Shewhart-type control charts are preferred. Cumulative sum (CUSUM) and exponentially weightedmoving average (EWMA) control charts are generally used to detect small and moderate shifts. Sh...

Automated public health records provide the necessary data for rapid outbreak detection. An adaptive exponentially weighted moving average EWMA plan is developed for signalling unusually high incidence when monitoring a time series of nonhomogeneous daily disease counts. A Poisson transitional regression model is used to fit background/expected trend in counts and provides “one-day-ahead” forec...

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...

We characterize the commercial behavior of a group of companies in a common line of business, or network, by applying small ensembles of classifiers to a stream of records containing commercial activity information. This approach is able to effectively find a subset of classifiers that can be used to predict company labels with reasonable accuracy. Performance of the ensemble, its error rate un...

The LTPD plans for acceptance sampling which minimize the mean inspection cost per lot of the process average quality when the remainder of the rejected lots is inspected were originally designed by Dodge and Romig for the inspection by attributes. The sampling plans for the inspection by variables were then proposed and it has been shown that such plans are in many situations in practice more ...

EWMA control charts designed for monitoring the variance or the mean and the variance of a normally distributed variable are either based on the log transformation of the sample variance S or provide only rough ARL results. Gan (1995), as the most prominent example for the simultaneous case, calculated ARL values precisely for X̄-lnS EWMA schemes. The results in Knoth and Schmid (2002) for X̄-S o...

Charts for Autocorrelated Processes Hyun Cheol Lee Samsung Electronics, Semiconductor Business Quality Assurance Dept. Banwol-Dong, Hwasung-City Gyeonggi-Do, Korea 445-701 Phone: 82-31-208-4717 Fax: 82-31-208-6699 Email: [email protected] Daniel W. Apley (Corresponding Author) Department of Industrial Engineering and Management Sciences Northwestern University Evanston, IL 60208-3119 Phone: 8...