A hybrid metaheuristic routing algorithm for low-level picker-to-part systems

An application of an adapted Harmony Search (HS) algorithm is proposed in this study in order to minimize manual warehouses’ pickers travel distance. Firstly, the distance matrix has been determined through a hybrid algorithm, and then HS is used to compute the pickers' travel distance, developing a MATLAB® simulation model. This model performance is tested on twenty-five scenarios, resulting from variable length of the order pick lists and different manual storage configurations. Thirty picklists are evaluated for each scenario, for a total of 750 simulations. The results provided by the algorithm, compared with those returned by a metaheuristic algorithm and two heuristic routing policies, suggest that HS provides better outputs results than the remaining algorithms. The algorithm is also very efficient from a computational perspective; as order picking is an operational decision, the short computational time allows the pickers route to be defined even in real-time if needed.