Diseño y mejora de gráficos de control multivariantes para atributos. Un enfoque basado en teoría difusa

[EN] The Statistical Process Control (SPC) is a method used to control the quality characteristics of a product during the production process, determine whether the manufacturing process is or not stable and improve its capacity through the reduction of variability. One of the main tools used in the...

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Detalles Bibliográficos
Autor: Pastuizaca Fernández, María Nela
Tipo de recurso: tesis doctoral
Fecha de publicación:2016
País:España
Institución:Universitat Politècnica de València (UPV)
Repositorio:RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
Idioma:español
OAI Identifier:oai:riunet.upv.es:10251/65073
Acceso en línea:https://riunet.upv.es/handle/10251/65073
Access Level:acceso abierto
Palabra clave:Control de Calidad
Gráficos de control
Hotelling T2
Multinomial multivariante
Teoría difusa
ARL
ESTADISTICA E INVESTIGACION OPERATIVA
Descripción
Sumario:[EN] The Statistical Process Control (SPC) is a method used to control the quality characteristics of a product during the production process, determine whether the manufacturing process is or not stable and improve its capacity through the reduction of variability. One of the main tools used in the SPC is the control chart. Often the quality of a product is measured through various quality characteristics generally correlated. Multivariate Control charts are a response to the need for quality control in such situations. If the quality characteristics are qualitative, sometimes it happens that the product quality is defined by linguistic variables and product units are also classified by linguistic forms into several categories, depending on the degree of fulfillment of expectations, creating a situation of fuzzy classifications. The control charts proposed in the literature to deal with such situations are mostly based on simulation and using approximation techniques which hinder the practical application thereof. This thesis addresses this issue proposing a multivariate control chart for quality characteristics of multi-type attributes correlated based on the T2 control chart of Hotelling, using a fuzzy approach. The results of the proposed control charts before are improved by establishing a more formal way of measuring and evaluating quality in these diffuse situations. A method is also proposed to assess the performance of control chart proposed, by deter mining the average run length (ARL), in both in-control state and the out-of-control state. For this, algorithms which use Monte Carlo simulation are developed and implemented in R. Additionally, the sensitivity of the control chart faced with the choice of the membership functions of linguistic variables is analyzed.