An effective warranty servicing strategy should be made considering both warranty cost and product availability. Based on the two-dimensional free repair warranty, a strategy combining the imperfect preventive maintenance and minimal repair is proposed where the imperfect preventive maintenances are implemented in a special subregion of the warranty and all other failures are repaired minimally...

achieving optimal production cycle time for improving manufacturing processes is one of the common problems in production planning. during recent years, different approaches have been developed for solving this problem, but most of them assume that mean quality characteristic is constant over production run length and sets it on customer’s target value. however, the process mean may drift from ...

the problems of sequential change-point have several important applications in quality control, signal processing, and failure detection in industry and finance. we discuss a bayesian approach in the context of statistical process control: at an unknown time $tau$, the process behavior changes and the distribution of the data changes from p0 to p1. two cases are considered: (i) p0 and p1 are fu...

In general, a newly purchased item or system is warranted for a specific period. When the system fails during the warranty period, it is repaired free of charge. Even if the system is repairable, there exists some warranty services under which the manufacturer replaces the failed system during the warranty period. This study considers a case where a manufacturer offers an additional warranty se...

Some examples of absurd uniformly minimum variance unbiased estimators are discussed. Two reasons, argued in the literature, for having such estimators are lack of enough information in the available data and property of unbiasedness. In this paper, accepting both of these views, we show that an appropriate choice of loss function using a general concept of unbiasedness leads to risk unb...

We consider the problem of outsourcing warranty repairs to outside vendors when items have priorities in service. The manufacturer has a contract with a fixed number of repair vendors. The manufacturer pays a fixed fee for each repair done by a vendor which is independent of the repair type and priority class but depends on the vendor. There are a fixed number of items under warranty, and each ...

I this paper, we study a firm that faces demand from two sources: demand for new items and demand to replace failed items under warranty. We model this setting as a multiperiod single-product inventory problem where the demands for new items in different periods are independent and the demands for replacing failed items depend on the number and ages of the items under warranty. We consider back...

The quality loss function developed by Genichi Taguchi considers three cases, nominal-thebest, smaller-the-better, and larger-the-better. The methodology used to deal with the larger-thebetter case is slightly different than the other two cases. This research employs a term called target-mean ratio to propose a common formula for all three cases to bring about similarity among them. The target-...