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Monitoring correlated processes with binomial marginals

Weiss, Christian - In: Journal of Applied Statistics 36 (2009) 4, pp. 399-414

Few approaches for monitoring autocorrelated attribute data have been proposed in the literature. If the marginal process distribution is binomial, then the binomial AR(1) model as a realistic and well-interpretable process model may be adequate. Based on known and newly derived statistical...

Persistent link: https://www.econbiz.de/10004992274

Optimal exponentially weighted moving average (EWMA) plans for detecting seasonal epidemics when faced with non-homogeneous negative binomial counts

Sparks, R. S.; Keighley, T.; Muscatello, D. - In: Journal of Applied Statistics 38 (2011) 10, pp. 2165-2181

Exponentially weighted moving average (EWMA) plans for non-homogeneous negative binomial counts are developed for detecting the onset of seasonal disease outbreaks in public health surveillance. These plans are robust to changes in the in-control mean and over-dispersion parameter of the...

Persistent link: https://www.econbiz.de/10009279036

A Sequential Markov Chain Monte Carlo Approach to Set-up Adjustment of a Process over a Set of Lots

Colosimo, B. M.; Pan, R.; Castillo, E. del - In: Journal of Applied Statistics 31 (2004) 5, pp. 499-520

We consider the problem of adjusting a machine that manufactures parts in batches or lots and experiences random offsets or shifts whenever a set-up operation takes place between lots. The existing procedures for adjusting set-up errors in a production process over a set of lots are based on the...

Persistent link: https://www.econbiz.de/10005492098

Modelling of unexpected shift in SPC

Zeifman, Michael; Ingman, Dov - In: Journal of Applied Statistics 32 (2005) 4, pp. 375-386

Optimal statistical process control (SPC) requires models of both in-control and out-of-control process states. Whereas a normal distribution is the generally accepted model for the in-control state, there is a doubt as to the existence of reliable models for out-of-control cases. Various...

Persistent link: https://www.econbiz.de/10005458434

Generally weighted moving average control charts with fast initial response features

Chiu, Wen-Chih - In: Journal of Applied Statistics 36 (2009) 3, pp. 255-275

The generally weighted moving average (GWMA) control chart is an extension model of exponentially weighted moving average (EWMA) control chart. Recently, some approaches have been proposed to modify EWMA charts with fast initial response (FIR) features. We introduce these approaches in GWMA-type...

Persistent link: https://www.econbiz.de/10004992271

Modified Shewhart Charts for High Yield Processes

Chang, Tee Chin; Gan, Fah Fatt - In: Journal of Applied Statistics 34 (2007) 7, pp. 857-877

The conventional Shewhart p or np chart is not effective for monitoring a high yield process, a process in which the defect level is close to zero. An improved Shewhart np chart for monitoring high yield processes is proposed. A review of control charts for monitoring high yield processes is...

Persistent link: https://www.econbiz.de/10005492092

An NP Control Chart Using Double Inspections

Wu, Zhang; Wang, Qinan - In: Journal of Applied Statistics 34 (2007) 7, pp. 843-855

degree and achieves the performance improvement without requiring extra inspection (testing whether a unit is conforming or …

Persistent link: https://www.econbiz.de/10005492097

On the Superiority of a Variable Sampling Interval Control Chart

Mahadik, Shashibhushan B.; Shirke, Digambar T. - In: Journal of Applied Statistics 34 (2007) 4, pp. 443-458

The paper establishes the analytical grounds of the uniform superiority of a variable sampling interval (VSI) Shewhart control chart over the conventional fixed sampling interval (FSI) control chart, with respect to the zero-time performance, for a wide class of process distributions. We provide...

Persistent link: https://www.econbiz.de/10005492129

Adjusted-loss-function charts with variable sample sizes and sampling intervals

Wu, Zhang; Tian, Yu; Zhang, Sheng - In: Journal of Applied Statistics 32 (2005) 3, pp. 221-242

Recent research has shown that the control charts with adaptive features are quicker than the traditional static Shewhart charts in detecting process shifts. This article presents the design and implementation of a control chart based on Adjusted Loss Function (AL) with Variable Sample Sizes and...

Persistent link: https://www.econbiz.de/10005492177

The random intrinsic fast initial response of one-sided CUSUM charts

Luceno, Alberto; Puig-Pey, Jaime - In: Journal of Applied Statistics 33 (2006) 2, pp. 189-201

starting point following the natural or intrinsic probability distribution of the CUSUM statistic. By definition, this … probability distribution remains stable as the chart is used. The probability that the chart starts at zero according to this …-length probability distributions for one-sided CUSUM charts initialized using this random intrinsic fast initial response (RIFIR) scheme …

Persistent link: https://www.econbiz.de/10005458205