Designing random collaborative warranty and customizing maintenance strategies for systems subject to mission cycles

Existing warranties are made by manufacturers subjectively and unilaterally with the aims of cutting costs, increasing sales volumes, and so on. However, they fail to meet users' individual needs such as effectively managing reliability or ensuring higher and stable production capacities. In response to this situation, the current paper puts forward random collaborative warranty models subject to mission cycles. In these models, manufacturers and users jointly set terms to fit users' actual needs. These warranties not only fulfill personalized needs but also function as value-added services, thus creating profit-making opportunities for manufacturers. Moreover, aiming to effectively manage the post-warranty reliability of systems, the paper devises post-warranty maintenance strategies such as trivariate random replacement with preventive maintenance and bivariate random combination replacement. The strategies' terms are based on different usage rate scenarios of the post-warranty system, which are determined by whether limited missions are completed before a specific time. The proposed solutions are modeled quantitatively, and numerical analyses are conducted on some typical aspects to uncover the underlying mechanisms and derive valuable insights. One notable finding is that users can achieve lower repair costs if they actively apply the two-scale approach following the 'whichever expires last' principle.