forward and reverse flows have to be coordinated aiming to optimize inventory and logistics costs, and to provide high service levels (de la Fuente et al., 2008). Problem complexity arises when the LSP is working in a supply chain where a coordination process between forward and reverse flows is essential (Gnoni et al., 2003; Pokharel and Mutha, 2009): demands of empty pallets required by inbound deliveries from upstream customershave to be synchronized with ones required for deliveries to downstream customers (Bogataj and Bogataj, 2003).