Research On Order Batch Problem Of Subcontracting System

As a kind of manual order-picking system, put systems’major operation is to distribute the pre-picked items to the designated customers, which are particularly popular in case a large number of customer order lines have to be picked in a short time window. In view of the characteristics of limited storing time of items, this thesis mainly researches on the order batching problem of put systems. First of all, introduce the background, purpose and significance of this topic in detail and make a review of research, offering the indispensable theoretical support to research. Second, construct a multi-aisle model of put systems based on static order-picking systems, state operation assumption for put systems, and choose total travel distance as the key performance indicator. Third, describe order batching problem for put systems and build a bi-level programming model, providing the model foundation to following proposed solution algorithm. Upper-level model’s objective function is total travel distance, while lower-level model figure out the order batching problem of each batch set, according to solution passed by upper-level model and the given order batching method. Then, propose MADS-RHA for bi-level programming model, in which Mesh Adaptive Direct Search (MADS) is responsible for solve the upper-level model, while Route Heuristic Algorithm (RHA) is used for figuring out the lower-level model. Finally, design a simulation experiment based on a case, then through comparisons between GA-RHA and MADS-M1LP and sensitivity analysis, the results shows that the proposed solution is superior in both convergence rate and optimization ability.