Bermawi P. Iskandar

A new repair-replace strategy for items sold with a two-dimensional warranty

For repairable items, the manufacturer has the option to either repair or replace a failed item that is returned under warranty. In this paper, we look at a new warranty servicing strategy for items sold with two-dimensional warranty where the failed item is replaced by a new one when it fails for the first time in a specified region of the warranty and all other failures are repaired minimally. The region is characterised by two parameters and we derive the optimal values for these to minimise the total expected warranty servicing cost. We compare the results with other repair-replace strategies reported in the literature.

A repair-replace strategy based on usage rate for items sold with a two-dimensional warranty

Abstract When a repairable item fails under warranty, the manufacturer has the option of either repairing the failed item or replacing it with a new one. In this paper, a repair–replace strategy is discussed for the manufacturer of a product sold with a two-dimensional warranty. The strategy is based on a specified region of the warranty defined in terms of age and usage with the first failure in the region rectified by replacement and all other failures being minimally repaired. An accelerated failure time (AFT) model is used to allow for the effect of usage rate on item degradation.

Last time buy decisions for products sold under warranty

Manufacturers supplying products under warranty need a strategy to deal with failures during the warranty period: repair the product or replace it by a new one, depending on e.g. age and/or usage of the failed product. An (implicit) assumption in virtually all models is that new products to replace the failed ones are immediately available at given replacement costs. Because of the short life cycles of many products, manufacturing may be discontinued before the end of the warranty period. At that point in time, the supplier has to decide how many products to put on the shelf to replace failed products under warranty that will be returned from the field (the last time buy decision). This is a trade-off between product availability for replacement and costs of product obsolescence. In this paper, we consider the joint optimization of repair-replacement decisions and the last time buy quantity for products sold under warranty. We develop approximations to estimate the total relevant costs and service levels for this problem, and show that we can easily find near-optimal last time buy quantities using a numerical search. Comparison to discrete event simulation results shows an excellent performance of our methods.

Warranty Servicing with Imperfect Repair for Products Sold with a Two-Dimensional Warranty

In this paper, a new servicing strategy servicing strategy with imperfect repair is defined and studied for the manufacturer of a product sold with a two-dimensional warranty. The strategy is based on a specified region region of the warranty defined in terms of age and usage, with the first failure in the region rectified by an imperfect repair and all other failures being minimally repaired. Product failures are modeled using an accelerated failure time (AFT) model that allows for the effect of usage rate on item degradation.

AN OPPORTUNITY-BASED AGE REPLACEMENT POLICY CONSIDERING WARRANTY

This study discusses an opportunity-based age replacement policy for a system which has a warranty period (0, S]. When the system fails at its age x≤S, a minimal repair is performed. If an opportunity occurs to the system at its age x for S<x<T, we take the opportunity with probability p to preventively replace the system, while we conduct a corrective replacement when it fails on (S, T). Finally if its age reaches T, we execute a preventive replacement. Under this replacement policy, the design variable is T. For the case where opportunities occur according to a Poisson process, a long-run average cost of this policy is formulated under a general failure time distribution. It is, then, shown that one of the sufficient conditions where a unique finite optimal T* exists is that the failure time distribution is IFR (Increasing Failure Rate). Numerical examples are also presented for the Weibull failure time distribution.

Maintenance Service Contracts for Equipment Sold with Two Dimensional Warranties

Abstract HeThis paper deals with maintenance service contracts for equipment (such as dump trucks) sold with two dimensional warranties. We consider a situation where an agent offers several maintenance contract options and the owner of the equipment has to select the optimal option. As the availability of the equipment is a critical measure for attaining the owner’s business objectives, the maintenance contract options offered need to ensure a high availability of the equipment. We study three maintenance service options considering the availability target from both the owner and OEM point of views and use a non-cooperative game formulation to determine the optimal price structure (i.e., the contract price and repair cost) for the OEM and the optimal contract option for the owner.

Comments on “Maintenance policies with two-dimensional warranty”

Chen and Popova [Res. Engng Syst. Saf. 77 (2002) 61] discuss maintenance policies for items sold with a two-dimensional warranty. However, their paper fails to give a proper review of the literature and it also contains errors. In this note we first review the relevant literature and then comment on the errors in their analysis

Performance-based maintenance contract for equipments used in mining industry

In this paper, we study performance based maintenance contracts for dump trucks operated in a mining industry. The service contract is characterised by two dimensional limits - one limit representing age and the other limit usage. In a performance based service contract uses an attractive incentives to motivate the the agent to increase the equipments performance beyond the target, and this in turn gives benefit for both the owner of the trucks and the Agent of service contract. In this paper, we study performance based maintenance service contracts for equipment used in a mining industry and the equipment is sold with two dimensional warranties and the perfomances considered includes availability and safety measures. We consider a situation where an agent offers several service contract options and the owner of equipment has to select the optimal option. We obtain the optimal strategy (pricing structure) for the agent and the optimal option for the owner using a stackelberg game formulation in which the agent is as a leader and the owner as a follower.

Two Dimensional Maintenance Contracts for a Fleet of Dump Trucks Used in Mining Industry

In this paper, we study two dimensional maintenance contracts for a fleet of dump trucks operated in a mining industry. The two-dimensional contract is charaterised by two parameters (i.e. age and usage limits) which define a region. Two different shapes of the contract region are studied, where one region favors the customer, and the other the service provider. The maintenance service contracts studied is the performance based contract which offers incentives to motivate a service provider (an agent) to increase the equipment’s performance beyond the target. This in turn gives benefit for both the owner of the trucks and the agent of service contract. The decision problem under study is that an agent offers several two dimensional service contract options and the owner of the trucks has to select the optimal option. We use a Nash game theory formulation in order to obtain a win-win solution – i.e. the optimal strategy (pricing structure) for the agent and the optimal option for the owner.

Performance-based maintenance contract for a fleet of dump trucks used in mining industry

In this paper, we study two dimensional maintenance contracts for a fleet of dump trucks operated in a mining industry. We consider performance based service contracts which offer attractive incentives to motivate a service provider (an agent) to increase the equipments performance beyond the target. This in turn gives benefit for both the owner of the trucks and the Agent of service contract. The situation under study is that an agent offers several two dimensional service contract options and the owner of the trucks needs to select the optimal option. We use a stackelberg game formulation in which the agent is as a leader and the owner as a follower to obtain the optimal strategy (pricing structure) for the agent and the optimal option for the owner.