if a direct interchange is working, return flows of empty pallets are directly connected to forward deliveries; thus, uncertainty in pallet quantity could be reduced. Otherwise when a postponed interchange system is applied, return flows are more uncertain even if a maximum delay period is allowed by the company. Uncertainty in quality of return products could also affect the performance of closed loop pallet management systems .when direct interchange is applied, the quality of the returned flows is less uncertain than in postponed one as the quality check process is carried out immediately on the delivery trip.