In this study, a new approach has been proposed for selecting appropriate maintenance strategies. For this purpose, decision making grid (DMG) has been developed. Sigma level and process capability indexes have been used based on the metric of mean time between failures (MTBF). The proposed...

In quality control, we may confront imprecise concepts. One case is a situation in which upper and lower specification limits (SLs) are imprecise. If we introduce vagueness into SLs, we face quite new, reasonable and interesting processes, and the ordinary capability indices are not appropriate...

Purpose – The purpose of this paper is to develop an yield-based process capability index (PCI), C py , to overcome the shortcomings of existing PCIs that limit their use and lead to inaccurate measures of quality conformance under a variety of common conditions. Design/methodology/approach...

Purpose – The purpose of this paper is to propose a set of process capability indices (PCIs) which are based on robust and agile statistics such that they may be applicable irrespective of the process status. Design/methodology/approach – The four popular PCIs – Cp, Cpk, Cpm and Cpmk –...

We propose and study a class of regression models, in which the mean function is specified parametrically as in the existing regression methods, but the residual distribution is modeled nonparametrically by a kernel estimator, without imposing any assumption on its distribution. This...

This paper estimates the drift parameters in the fractional Vasicek model from a continuous record of observations via maximum likelihood (ML). The asymptotic theory for the ML estimates (MLE) is established in the stationary case, the explosive case, and the boundary case for the entire range...