Multi-Objective joint maintenance and inventory optimization model with considering obsolescence and incremental discounts for spare parts

Many researches have studied joint maintenance and inventory optimization systems in order to find the best approach to simultaneous determination of spare part numbers and age replacement policies. Previous studies have not considered the risk of obsolescence that may occur when the spare parts are held for a long time. Obsolescence results in a partial or total loss of value of the spare parts. In this paper, we propose a new multi-objective model for preventive replacement of parts that are subject to obsolescence over a planning horizon. The objectives considered in the model are corrective replacement and its consequences, residual lifetime objective, obsolescence time objective, and Investment. Additionally, the incremental discounts are considered in the model to obtain results that are more realistic. Genetic Algorithms are a popular meta-heuristic that is particularly well-suited for this class of problems Thus, the multi objective Genetic Algorithm is used to solve the proposed model. Finally, a numerical example is provided to illustrate the use of this model.