Hotelling’s t² control charts based on robust estimators

Under the presence of multivariate outliers, in a Phase I analysis of historical set of data, the T² control chart based on the usual sample mean vector and sample variance covariance matrix performs poorly. Several alternative estimators have been proposed. Among them, estimators based on the minim...

Full description

Autores:
Yáñez Canal, Sergio
González Alvarez, Nelfi Gertrudis
Vargas Navas, José Alberto
Tipo de recurso:
Article of journal
Fecha de publicación:
2010
Institución:
Universidad Nacional de Colombia
Repositorio:
Universidad Nacional de Colombia
Idioma:
spa
OAI Identifier:
oai:repositorio.unal.edu.co:unal/37603
Acceso en línea:
https://repositorio.unal.edu.co/handle/unal/37603
http://bdigital.unal.edu.co/27687/
Palabra clave:
Multivariate Control Charts
MVE Estimators
Outliers
S Estimators.
Rights
openAccess
License
Atribución-NoComercial 4.0 Internacional
Description
Summary:Under the presence of multivariate outliers, in a Phase I analysis of historical set of data, the T² control chart based on the usual sample mean vector and sample variance covariance matrix performs poorly. Several alternative estimators have been proposed. Among them, estimators based on the minimum volume ellipsoid (MVE) and the minimum covariance determinant (MCD) are powerful in detecting a reasonable number of outliers. In this paper we propose a T² control chart using the biweight S estimators for the location and dispersion parameters when monitoring multivariate individual observations. Simulation studies show that this method outperforms the T²control chart based on MVE estimators for a small number of observations.