Distributional and Inferential Properties of Process Capability Indices

Um índice de capacidade para especificações unilaterais

“…Nos últimos anos, o uso de índices de capacidade nas indústrias de manufatura tem-se intensificado, além disso, esse procedimento tem recebido uma atenção substancial na literatura estatística voltada para o controle de qualidade. Veja, por exemplo, os trabalhos de Bissel (1990), Boyles (1991), Spiring (1991), Johnson (1992), Pearn & Johnson (1993), Kotz & Johnson (1992), Pearn & Kotz (1994), Chen (1994-95), Choi;Nam & Park (1996), Gupta & Kotz (1997), Pearn & Chen (1997), Kaminsky et al (1998), Wang & Chen (1998-99), Bothe (1999), Wen & Mergen (1999), Borges & Ho (2000, 2001 e muitos outros autores. Os índices mais freqüentemente usados para avaliar a capacidade do processo são C p e C pk , definidos respectivamente por:…”

Process Quality Analysis of Products

“…Kane [1], Chan et al [2], Choi & Owen [3], Boyles [4,5], Singhai [6], Pearn et al [7], and Chen [8] and others have all reported on this field. However, most studies were limited to discussing a process in terms of a single quality characteristic.…”

Testing capability indices for manufacturing processes with asymmetric tolerance limits and measurement errors

“…The C pm index suggested by Chan et al [6] involves the variation of production items with respect to the target value and the tolerance limits that are preset in the factory. Combining the advantages of these previous indices, Pearn et al [7] introduced the C pmk index. For a process with lower and upper tolerance limits LSL and U SL, and a target T set to the midpoint m = (LSL + U SL)/2 of the tolerance interval, Vännman [8] constructed a unified superstructure for the Correspondence: daniel.grau@univ-pau.fr four previous basic indices which can be defined as…”