Three-dimensional warranty and post-warranty maintenance of products with monitored mission cycles

This article explores the use of advanced digital technologies as a support in enhancing reliability management during the warranty stage. While previous studies have focused on the influence of monitored mission cycles on product reliability, they have overlooked the importance of failure numbers in warranty management. This article proposes a practical approach that combines mission cycles and failure numbers to model warranties and improve reliability management. The integration of these factors in warranty models, as well as the investigation of post-warranty maintenance policies, remains unexplored. To address this gap, we develop three types of three-dimensional warranties that incorporate limitations into mission cycles, failure numbers, and warranty duration. These warranties aim to effectively manage product reliability during the warranty stage while controlling warranty costs. The warranty costs and service periods of the developed warranties are derived and analysed. Subsequently, taking into account the limited mission cycles and the planned working time in the post-warranty stage, three post-warranty maintenance policies are investigated to manage product reliability during the post-warranty stage. The average cost rates of the proposed post-warranty maintenance policies are calculated from a perspective of the life cycle, and the structural properties of the optimal policies are explored both analytically and numerically. Finally, the proposed models are illustrated, and numerical comparisons of different policies are conducted by unifying the dimensions of the measures.