| Abstract: | This article generalizes the model for the economic design of x̄-control charts of Duncan 4], starting from the more recent papers of Lorenzen and Vance 8] and Banerjee and Rahim 3]. The classical model of Duncan 4] and its several extensions including the unified model of Lorenzen and Vance 8] assumed exponentially distributed in-control periods and provided uniform sampling schemes. Banerjee and Rahim 3], however, assumed a Weibull-distributed in-control period having an increasing failure rate and used variable sampling intervals. The present article is an extension of the work of Banerjee and Rahim 3], where a general distribution of in-control periods having an increasing failure rate is assumed and the possibility of age-dependent repair before failure is considered. Several different truncated and nontruncated probability models are chosen. It is proposed that economic benefits can be achieved by adopting a nonuniform inspection scheme and by truncating a production cycle when it attains a certain age. Numerical examples are presented to support this proposition. Finally, the effect of model specification in the choice of failure mechanism is investigated. © 1993 John Wiley & Sons, Inc. |
