Cost analyses on warranty policies for systems subject to two types of warranty periods.

摘要

In general, a warranty is an obligation attached to products that requires the manufacturers to provide compensation for customer (buyer) according to the warranty terms when the warranted products fail to perform their intended functions [179]. A warranty is important to the manufacturer as well as the customer of any commercial product since it provides protection to both parties. As for the customer, a warranty provides a resource for dealing with items that fail due to the uncertainty of the product's performance and unreliable products. For the manufacturer, it provides protection since the warranty terms explicitly limit the responsibility of a manufacturer in terms of both time and type of product failure. Because of the role of the warranty, manufacturers have developed various types of warranty policy to grab the interest of the customers. However, manufacturers cannot extend the warranty period without limit and maximize warranty benefits because of the cost related to it.;Many researchers have investigated on the topic of warranty modeling and policy and expanded their studies of warranty in various different conditions, i.e., maintenance policies.;In this dissertation, we focus on the developments of warranty cost models with various maintenance policies as well as the warranty policy with post warranty periods for single-component and multi-component systems including parallel-series, series-parallel and k-out-of-n systems from the perspectives of consumer and manufacturer, maintenance policies and repair policies. First, the role, concept and other factors of the warranty policies, are introduced. We conduct the literature review and present the selected mathematical background that will be used throughout the dissertation.;We develop several warranty cost models and derive reliability measures for various systems including series-parallel, parallel-series, and k-out-of-n configurations based on the proposed alter- and mixed-quasi-renewal processes. We focus on the warranty cost analysis including repairable products with a given warranty period using the induction method. Additionally, we use the non-homogenous Poisson process and minimal repair to develop warranty cost models for the k-out-of-n systems in the warranty period subject to failure times and repair times (two dimensional model). We combine maintenance policies and several warranty policies such as failure repair/replacement warranty, pro-rata warranty and combination warranty into the cost analysis. Additionally, we investigate the maintenance policies with warranty period and post warranty period based on two dimensions such as failure times and repair times. Finally, we present concluding remarks and future research topics.