Search Results - subject:"PROCESS CONTROL"

Testing hypothesis on stability of expected value and variance

Konczak, Grzegorz; Wywial, Janusz - In: Operations Research and Decisions 1 (2006), pp. 73-83

process control. The critical values for these statistics have been found using numerical integration. The tables with …

Persistent link: https://www.econbiz.de/10008777298

A bootstrap view on dickey-fuller control charts for AR(1) series

Steland, Ansgar (contributor) - 2006

Dickey-Fuller control charts aim at monitoring a random walk until a given time horizon to detect stationarity as early as possible. That problem appears in many fields, especially in econometrics and the analysis of economic equilibria. To improve upon asymptotic control limits (critical...

Persistent link: https://www.econbiz.de/10003309053

Effect of Estimation of the Process Parameters on the Control Limits of the Univariate Control Charts for Process Dispersion

Maravelakis, Petros - 2006

Control charts are extensively used in many real world applications. Since process parameters are rarely known, common practice is to estimate them. Then, the control limits are modified and become actually random variables. In this paper, we deal with the univariate control charts for...

Persistent link: https://www.econbiz.de/10012779034

Identifying the Out of Control Variable in a Multivariate Control Chart

Maravelakis, Petros - 2006

The identification of the out of control variable, or variables, after a multivariate control chart signals, is an appealing subject for many researchers in the last years. In this paper we propose a new method for approaching this problem based on principal components analysis. Theoretical...

Persistent link: https://www.econbiz.de/10012779055

An Examination of the Robustness to Non Normality of the Ewma Control Charts for the Dispersion

Maravelakis, Petros - 2006

The EWMA control chart is used to detect small shifts in a process. It has been shown that, for certain values of the smoothing parameter, the EWMA chart for the mean is robust to non normality. In this article, we examine the case of non normality in the EWMA charts for the dispersion. It is...

Persistent link: https://www.econbiz.de/10012780188

Multivariate Statistical Process Control Charts and the Problem of Interpretation : A Short Overview and Some Applications in Industry

Bersimis, Sotiris - 2006

Woodall and Montgomery in a discussion paper, state that multivariate process control is one of the most rapidly … developing sections of statistical process control. Nowadays, in industry, there are many situations in which the simultaneous … which several related variables are of interest are collectively known as Multivariate Statistical Process Control (MSPC …

Persistent link: https://www.econbiz.de/10012780593

Control Charts for the Lognormal Distribution

Maravelakis, Petros; Panaretos, John; Psarakis, Stelios - 2006

Control Charts are the main tools of Statistical Process Control. They are used for deciding whether a process is …

Persistent link: https://www.econbiz.de/10014054272

Effect of Estimation on the Univariate Control Charts for Process Dispersion

Maravelakis, Petros; Panaretos, John; Psarakis, Stelios - 2006

Control charts are extensively used in many real world applications. Since process parameters are rarely known common practice is to estimate them. Then, the control limits are modified and become actually random variables. In this paper, we deal with the univariate control charts for dispersion...

Persistent link: https://www.econbiz.de/10014054283

The causes of never events in hospitals

Gitlow, Howard; “Amy” Zuo, Qun; Ullmann, Steven G.; … - In: International Journal of Lean Six Sigma 4 (2013) 3, pp. 338-344

Purpose – The purpose of this paper is to posit that it is possible to identify contributing factors for “never events,” preventable adverse events in the healthcare setting, and to develop “best practices” to prevent them. Design/methodology/approach – This paper focuses on three...

Persistent link: https://www.econbiz.de/10014782635

A case of implementing SPC in a pulp mill

Rantamäki, Jukka; Tiainen, Eeva‐Liisa; Kässi, Tuomo - In: International Journal of Lean Six Sigma 4 (2013) 3, pp. 321-337

paper is to contribute to the body of knowledge on applying statistical process control (SPC) methods in a pulp mill …

Persistent link: https://www.econbiz.de/10014782700