Deterministic Inventory Lot-Size Models with Time-Varying Demand and Cost under Generalized Holding Costs

摘要

In this paper, we generalize the EOQ model by Khouja and Park to allow for not only time-varying demand but also unequal cycle time. We prove that there exists a unique optimal replenishment schedule and show that the total relevant cost is a convex function of the number of replenishments, which simplifies the search for the optimal number of replenishments to find a local minimum. Therefore, a simple iterative algorithm to obtain the optimal replenishment number and time scheduling is provided. In addition, an easy and simple heuristic algorithm to obtain the optimal solution for the lot-sizing model by Khouja and Park is also proposed. Finally, numerical examples for illustrating the model are provided.