A novel optimal single machine replacement policy using a single as well as a two-stage decision making process is proposed based on the quality of items produced. In a stage of this policy, if the number of defective items in a sample of produced items is more than an upper threshold, the machine is replaced. However, the machine is not replaced if the number of defective items is less than ...

In this paper we consider an imperfect production system which produces good and defective items and assume that defective items can be reworked. Due to the nature of rework process we do not restrict the rework rate to be equal to normal production rate or constant and assume that it is a random variable with an arbitrary distribution function. We also assume as it is true in most real world s...

The paper determines the optimum qualities and prices of two substitute products for a manufacturer cum retailer in an imperfect production process over a random planning horizon for maximum profit. In this Economic Production Lot-size (EPL) process, items are produced simultaneously, defective production commences during the out-of-control state after the passage of some time from the commence...

Uncertainty theory has got quite attention after it was pioneered by Baoding Liu in 2007. Uncertainty is the newest area among the concepts to express imprecise quantities which can be expressed by the ambiguity of human language. Such an unpredictable value can be neither accurately described by probability theory nor fuzzy logic. In inventory models, costs are very prominent part of the syste...

Usually it is assumed that all items in a lot are of good quality, but in reality this assumption may not always be pertinent. Thus, the inspection of lots becomes essential in almost all organizations. Moreover, its role becomes more vital when the items are deteriorating in nature. Owing to this fact, this paper investigates the impact of initial inspection on retailer’s pricing and ordering ...

Medical researchers may be interested in disease processes‎  ‎that are not‎ ‎directly observable‎. ‎Imperfect diagnostic‎ ‎tests may be used repeatedly to monitor the‎ ‎condition of a patient in the absence of a gold standard.‎ ‎We consider parameter identifiability and estimability‎ ‎in a Markov model for alternating binary longitudinal ‎responses that may be misclassified.‎ ‎Exactly ...

This paper deals with an integrated model for the joint determination of economic production quantity and preventive maintenance (PM) level for an imperfect process having a general deterioration distribution with increasing hazard rate. The effect of PM activities on the deterioration pattern of the process is modeled using the imperfect maintenance concept. It is assumed that, after each PM, ...