Solving Order Batching/Picking Problems with an Evolutionary Algorithm

We present an evolutionary algorithm to solve a combination of the Order Batching and Order Picking problems. This integrated problem consists of selecting and picking up batches of various items requested by customers from a storage area, given a deadline for finishing each order according to a delivery plan. We seek to find the plan that minimizes the total cost of picking the goods, proportional to the time devoted to traverse the storage facility, grabbing the good and leaving it at the dispatch area. Earliness and tardiness induce inefficiency costs due to the excess use of space or breaching the delivery contracts. The results of running the algorithm compare favorably to those reported in the literature.