Abstract:Storage unit design is the basis for distribution center planning.Firstly, based on the safe loading, this paper builds three models to designthe storage unit size. The first model, with the purpose of stacking themaximum number of boxes onto a pallet’s single-layer, is used to calculate thesingle-layer stacking number. The second one, with the purpose of maximumsurface utilization percentage, is used to select the length and width ofpallet. And the third one, with the purpose of maximum utilization percentagein height, is used to determine the height of the storage unit. Secondly, thispaper establishes two models to calculate characteristic values, which areaverage stacking number calculation model based on storage volume and ratedweight calculation model. Finally, the paper introduces the application of thisoptimization design method to the distribution center planning of a clothingenterprise. We get the optimal storage unit design scheme for improving cubeutilization, which shows that this optimization design method is effective.
Keywords:Distribution center; Storage unit; Optimization design; Stacking;Pallet
1. Introduction
Storage unit design is the basis forplanning storage area and selecting equipment, and it is very important to thedistribution center planning. At present, wide range of package sizes and lackof systemic theory and method in storage unit design, make the distributioncenter planning difficult, moreover reduce working efficiency, create resourceswaste and increase operation cost.
Some scholars have begun to engage in theresearch on palletizing of storage and transportation, such as the dynamiccharacteristics of assembly packaging unit at the vertical drive, the relationshipof pallet design and palletizing resonating under the sine drive, thedevelopment of mixed stacking algorithm and the automatic loading system. Inaddition, the system softwares used in packaging design and pallet loading havebeen developed, such as CAPE PACK (for pallet stacking packaging design) andTRUCKFILL (for the optimization design of truck and container loading)developed by CAPE Systems Group.[1-6]
In the base of studying the influencefactors of storage unit design, this paper explores a systemic method used instorage unit optimization design in order to ensure safe storage and maximizepallet surface and storage space. And the application of this optimizationdesign method in the distribution center planning of a clothing enterprise is introduced.
2. Designprinciple of storage unit
In order to design an optimal storageunit scheme, which ensures safe storage and utilizes the storage space sufficiently,two objectives are required: load intensity can guarantee cargos security, and thesurface utilization percentage of pallet and the utilization percentage inheight are both maximum. The research of storage unit optimization designincludes the following two points: storage unit size design (including palletlength and width, storage unit height); storage unit characteristic valuescomputation (including average stacking number and rated weight). In thisstorage unit optimization design method, we assume that each storage unit reservesidentical cargos. First of all, we can determine the value range of the storageunit sizes according to some conditions such as national standards and presentstatus of the enterprise. Then the mathematical models are set up, which arebased on the objective function with maximum utilization percentage in thevalue range. Calculate the models and get the size of storage unit. Finally,count average stacking number and rated weight. The optimization design principleis shown in Fig. 1.