Individual T-2 Control Chart for Compositional Data

The usual Hotel ling T-2 control chart is not appropriate for monitoring processes where the quality characteristic is a mixture. The composition of mixtures are vectors of positive elements that represent parts of a whole, to which standard multivariate techniques are not appropriate due to their r...

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Bibliographic Details
Authors: Vives Mestres, Marina, Daunis-i-Estadella, Pepus, Martín Fernández, Josep Antoni
Format: article
Status:Versión enviada para evaluación y publicación
Publication Date:2014
Country:España
Institution:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repository:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:10256/10932
Online Access:http://hdl.handle.net/10256/10932
Access Level:Open access
Keyword:Anàlisi multivariable
Multivariate analysis
Description
Summary:The usual Hotel ling T-2 control chart is not appropriate for monitoring processes where the quality characteristic is a mixture. The composition of mixtures are vectors of positive elements that represent parts of a whole, to which standard multivariate techniques are not appropriate due to their restricted sample space. There are many applications where a mixture is monitored against time, such as in the chemical industry, product composition, impurity profile, or gas components analysis. In this paper, a multivariate control chart for individual compositional observations based on the T-2 statistic is proposed and compared with the typical one in terms of average run length. We show how results are more consistent with compositional data nature and illustrate implementation in a real-world example