Balancing Transport Efficiency and Bilateral Exchange Debts in Pallet Pooling

Pallet pooling systems enable the shared use of returnable transport items across multiple independent clients. A central operational challenge in such systems is the joint management of physical pallet flows and persistent bilateral imbalances arising from repeated exchanges between small companies. In this work, we address this challenge by introducing the Pallet Pooling Problem, a mathematical formulation that simultaneously minimizes total transport distance and deviations from existing bilateral pallet debts. Recognizing that operational priorities differ across industries, we discuss alternative objective functions that provide a flexible decision-support framework. We further present an open-source, optimal solution approach for the Pallet Pooling Problem, which scales to large instances and is easily adaptable. The approach is validated on operational data of a German SME.