Warranty cost analysis under imperfect repair

Abstract

Increasing market competition forces manufacturers to offer extensive warranties. Faced with the challenge of keeping the associated costs under control, most companies seek efficient rectification strategies. In this study, we focus on the repair strategies with the intent of minimizing the manufacturer’s expected warranty cost expressed as a function of various parameters such as product reliability, structure of the cost function and the type of the warranty contract. We consider both one- and two-dimensional warranties, and use quasi renewal processes to model the product failures along with the associated repair actions. We propose static, improved and dynamic repair policies, and develop representative cost functions to evaluate the effectiveness of these alternative policies. We consider products with different reliability structures under the most commonly observed types of warranty contracts. Experimental results indicate that the dynamic policy generally outperforms both static and improved policies on highly reliable products, whereas the improved policy is the best performer for products with low reliability. Although, the increasing number of factors arising in the analysis of two-dimensional policies renders generalizations difficult, several insights can be offered for the selection of the rectification action based on empirical evidence.