Controle on-line por atributos para o número de não-conformidades no item inspecionado com base em uma sequência de inspeção

• Autor(a) principal: Rocha, Andre Luiz Sena da
• Data de Publicação: 2010
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFRN
• Texto Completo: https://repositorio.ufrn.br/jspui/handle/123456789/15019
• topic: Controle on-line de processos por atributos; Número de não conformidades; Processo de poisson; Cadeia de markov; Limite de advertência; On-line control process for attributes; Non-conformities; Poisson process; Markov chain; Warning limit; CNPQ::ENGENHARIAS::ENGENHARIA DE PRODUCAO

This paper proposes a procedure to control on-line processes for attributes, using an Shewhart control chart with two control limits (warning limit and control limit) and will be based on a sequence of inspection (h). The inspection procedure is based on Taguchi et al. (1989), in which to inspect the item, if the number of non-conformities is higher than an upper control limit, the process needs to be stopped and some adjustment is required; and, if the last inspection h, from all items inspected present a number of non-conformities between the control limit and warning limit. The items inspected will suffer destructive inspection, being discarded after inspection. Properties of an ergodic Markov chain are used to get the expression of average cost per item and the aim was the determination of four optimized parameters: the sampling interval of the inspections (m); the constant W to draw the warning limit (W); the constant C to draw the control limit (C), where W £ C, and the length of sequence of inspections (h). Numerical examples illustrate the proposed procedure