Optimal Operation of Vending Machines

In this study, we address the operational policy problem faced by a seller managing a portfolio of vending machines. The objective of our study is to develop a mathematical model that optimally manages the operations of multi-item vending machines distributed across various locations to maximize profit. Our proposed model takes a comprehensive approach by simultaneously considering several key aspects such as pricing, inventory management, capacity planning, and route optimization while addressing demand uncertainty using a scenario-based approach. In particular, we aim to answer several key questions: which items should be available at each location and how many towers should be allocated for each item; what the optimal inventory level of these items should be at the beginning of each period; whether any transfers between locations are required during each time period; and what the price of each item should be at each location and for each period. The objective of our modeling approach is to determine a pricing policy that effectively balances demand and inventory. Numerical experiments are conducted to evaluate the robustness and efficiency of the model’s solutions.