Joint optimization of two-dimensional preventive maintenance parameters, technology level and product price under continuous usage rate and agent warranty services

An efficient two-dimensional warranty model with the possibility of extending after-sale services to the end of the product life is developed in which services in the extended warranty period are assigned to an agent as a transaction side. To control product failures, two factors are taken into account in the proposed model: (1) the manufacturing technology level which results in a different reliability outcome for the product; and (2) a two-dimensional maintenance policy with respect to customers' usage rate. In addition, in order to adapt the model to reality, we depart from the literature by considering the continuous nature of the usage rate variable. Finally, in order to confirm the effectiveness of the model, some comparative studies are carried out. The obtained results reveal that preventive maintenance (PM) activities lead to a considerable rise in cost savings. Besides, in comparison with one-dimensional PM policies based on product age and usage, using a two-dimensional PM policy improves the economic criteria. Furthermore, the presence of the agent has a great impact on reducing the customer's cost as well as the failure rate after the basic warranty period.