Routing automated lane-guided transport vehicles in a warehouse handling returns

Faced with high return rates, many e-commerce retailers are considering novel technical solutions to expedite the processing of returned items in their warehouses. One such solution consists lane-guided transport (LGT) vehicles. These small, electric vehicles follow optical markers on floor, picking up boxes at a depot and dropping them off workstations, releasing logistics workers focus productive task actually instead carrying through warehouse. types systems simple set from perspective; however, routes warehouse floor still need be carefully planned. This gives rise following routing problem. Given stations served multiple depots by fleet LGT vehicles, which doing what type work should visited route? Only one route per is allowed, but may use same route. Moreover, since cannot changed short notice, we consider an infinite planning horizon where demand rate depends they assigned do (e.g., handling defective or refurbishing). We develop decomposition heuristic, solves instances derived industry data near-optimality less than minute. also show that location rather unimportant for overall system performance, count can have significant influence.