A warranty is a contractual obligation incurred by a manufacturer (vendor or seller) in connection with the sale of a product. In broad terms, the purpose of warranty is to establish liability in the event of a premature failure of an item or the inability of the item to perform its intended function.One of the commonly used warranty policies, especially for electronic and mechanical products, is Free Replacement Warranty (FRW). Under FRW, the warrantor agrees to repair or replace any failed item up to time W (the length of the warranty period), from the time of purchase, at no cost to the consumer.An effective warranty servicing strategy is essential in reducing manufacturers’ warranty servicing costs and increasing profits from product sales. Warranty claims are not always due to product failures. They can also be caused by two types of humanfactors. On the one hand, consumers might claim warranty due to misuse and/or failures caused byvarious human factors. Such claims might account for more than 10% of all reported claims. On theother hand, consumers might not be bothered to claim warranty for failed items that are still underwarranty, or they may claim warranty after they have experienced several intermittent failures. Thesetwo types of human factors can affect warranty claim costs. So,The humanfactorplays an importantroleinmodeling thewarranty. We propose two models to estimate the expected warranty cost when the two typesof human factors are included. This paper is applying a 2-phase approach to find costs of tow failures. In first phase, cost of fatal failure is found and in the second phase we demonstrate algorithm for intermittent failures. Because of these two failures have difference in structure, so their costs optimizing must be different. For first phase, it has been assumed two repairs that called minimal repair and imperfect repair. In contrast, for solving the second phase we have utilized linear programming. Finally, Numerical examples are given to validate the results derived.