Results 171 to 180 of about 1,881 (223)
Some of the next articles are maybe not open access.
Estimation in Shewhart control charts: effects and corrections
Metrika, 2004The influence of the estimation of parameters in Shewhart control charts is investigated. It is shown by simulation and asymptotics that (very) large sample sizes are needed to accurately determine control charts if estimators are plugged in. Correction terms are developed to get accurate control limits for common sample sizes in the in-control ...
Albers, Willem, Kallenberg, Wilbert C.M.
openaire +2 more sources
The importance of time order with Shewhart control charts
Quality and Reliability Engineering International, 2017AbstractIn Phase I analysis, data are used retrospectively to check process stability and to establish limits that will be later used in Phase II for the prospective monitoring. It is clear that the results of Phase I analysis are of crucial importance for the right interpretation of control chart during Phase II. Many of recent papers devoted to Phase
V. Shper, Y. Adler
openaire +1 more source
A new sampling strategy for the Shewhart control chart monitoring a process with wandering mean
International Journal of Production Research, 2015 In many processes, such as in chemical and process industries, the observations of a quality characteristic to be monitored may be correlated, if sampling intervals are short.
Giovanni Celano +2 more
exaly +2 more sources
A Nonparametric Shewhart-Type Synthetic Control Chart
Communications in Statistics - Simulation and Computation, 2010In this article, we provide a nonparametric Shewhart-type synthetic control chart based on the signed-rank statistic to monitor shifts in the known in-control process median. The synthetic control chart is a combination of a signed-rank chart due to Bakir (2004) and a conforming run length chart due to Bourke (1991).
V. Y. Pawar, Digambar T. Shirke
openaire +1 more source
On the α-risks for shewhart control charts
Communications in Statistics - Simulation and Computation, 1992The performance of the usual Shewhart control charts for monitoring process means and variation can be greatly affected by nonnormal data or subgroups that are correlated. Define the αk-risk for a Shewhart chart to be the probability that at least one “out-of-control” subgroup occurs in k subgroups when the control limits are calculated from the k ...
C.S. Padgett, L.A. Thombs, W.J. Padgett
openaire +1 more source
Computation of the Performance of Shewhart Control Charts
IFAC Proceedings Volumes, 2004Abstract The perfonnance of a control chart in statistical process control is often quantified in terms of the Average Run length (ARL). The ARL enables a comparison to be undertaken between various monitoring strategies. These are often detennined through Monte Carlo simulation studies.
Pieter Mulder +2 more
openaire +1 more source
A New Combined Shewhart–Cumulative Sum S Chart for Monitoring Process Standard Deviation
Quality and Reliability Engineering International, 2016 The combined application of a Shewhart chart and cumulative sum (CUSUM) control chart is an effective tool for the detection of all sizes of process shifts as the scheme combines the advantages of a CUSUM at detecting small to moderate shifts and ...
Mu’Azu Ramat Abujiya +2 more
exaly +1 more source
2016
Process Control is the active correction of a process based on the results of process monitoring. Once the process monitoring tools have detected an assignable cause, this cause is removed to bring the process back into control. This chapter presents the process control techniques under fuzziness.
Cengiz Kahraman +2 more
openaire +1 more source
Process Control is the active correction of a process based on the results of process monitoring. Once the process monitoring tools have detected an assignable cause, this cause is removed to bring the process back into control. This chapter presents the process control techniques under fuzziness.
Cengiz Kahraman +2 more
openaire +1 more source
Design Considerations and Trade-offs for Shewhart Control Charts
2021When in-control parameters are unknown, they have to be estimated using a reference sample. The control chart performance in Phase II, which is generally measured in terms of the Average Run Length (ARL) or False Alarm Rate (FAR), will vary across practitioners due to the use of different reference samples in Phase I. This variation is especially large
openaire +3 more sources
Normality test by Shewhart control chart
Journal of Information and Optimization Sciences, 1999Abstract Transformed quantile-quantile (TQQ) and transformed probability-probability (TPP) plots are developed with control limits for the detection of deviations from the normal distribution. It will be shown that TQQ and TPP plots are useful methods for normality test when they are adopted with Shewhart control technique.
Jea-Young Lee +2 more
openaire +1 more source