Rolling Horizon Models for Inter-Depot Empty Container Repositioning

Abstract

Export customers requesting empty containers in the hinterland areas are serviced by maintaining sufficient inventory at each regional depot. The supply-demand imbalance at the regional level is stabilized by repositioning empty containers between inland depots. We propose an inter-depot empty container repositioning problem and a heuristic real-time decision algorithm to solve it. Initially, single-period travel time is considered and three models: Allocation Problem (AP), Value Approximation Model (SPL-VA), and Node Decomposition Heuristic (NDH-SP) are presented. The system is simulated over a certain time horizon by generating real-time supply and demand values, and the system’s evolution is studied under each of the proposed models. The VA models perform better than the AP with modest computational effort. The NDH-SP is further generalized to accommodate multi-period travel times. By simulating this algorithm with a demand rejection policy, we observe that maximum demand satisfaction is obtained by allowing medium-sized demand queues at the depots.