The Efficiency Of Remote Order-picking System With SBS/RS Technology

With the continuous development of e-commerce,people have higher and higher requirements for logistics efficiency.The order in e-commerce presents the characteristics of a large variety of products and small batch,which aggravates the difficulty of warehouse selection.Automated warehouse system,with its efficient and rapid picking ability,gradually replaces the traditional manual warehouse,and is widely used in production,distribution,retail and other links.Some researchers have provided single model studies that either investigate the performance of order picking systems or the performance of storage systems.In fact,they do not exist alone in the actual picking process,so it is very necessary to study the integrated system.Classified storage for different types of goods can improve the picking efficiency of the system.Commands can be divided into single-command and dual-command.Different commands also have an impact on the system picking efficiency.This paper studies SBS/R-ROPS and E-SBS/R-ROPS.Most of the researches on SBS/R-ROPS and E-SBS/R-ROPS focus on random storage strategy,but classification storage strategy can improve system efficiency for different types of goods.Therefore,it is necessary to study SBS/R-ROPS and E-SBS/R-ROPS under the classified storage strategy.In the existing research on classified storage strategy,SBS/R-ROPS is only studied in the single-command.In fact,the dual-command operation that the storage system executes the storage command first and then executes the retrieval command is more widely used.Therefore,it is necessary to conduct researches on SBS/R-ROPS and E-SBS/R-ROPS combining different commands and classified storage strategies.In this paper,SBS/R-ROPS and E-SBS/R-ROPS are studied under the classified storage strategy.Based on the travel time model,the mathematical analytical formula of average service time of lifts and shuttles with different command under the classified storage strategy are constructed.Furthermore,the open loop queuing network models of SBS/R-ROPS and E-SBS/R-ROPS are constructed based on the queuing network theory.The decomposition method is used for approximate solution.The validity of the model is verified by simulation.The queuing network model is used to explore the influence of the number of p icking stations,the number of channels and the single and double instruction mode on the SBS/R-ROPS efficiency,such as the completion time of picking orders,the utilization rate of shuttle vehicles and the utilization rate of lifts,under the classified storage strategy,and to carry out a comparative analysis of different storage strategies.The SBS/R-ROPS and E-SBS/R-ROPS configurations were optimized considering the two objectives of minimizing order picking time and minimizing cost.Given the order arrival rate and ABC curve parameter values,the number of aisles,floors,columns,partition configurationand the number of picking stations of shelves are determined to meet the customer's storage requirements.SBS/R-ROPS and E-SBS/R-ROPS multi-objective optimization models are established.In order to solve nonlinear discrete multi-objective problems,NSGA-? algorithm is used to solve the model,and an example is analyzed.The Pareto solution set obtained can provide decision support for the warehouse designer.Under different classification storage strategies,different ABC curve parameter values,different number of picking stations,different number of aisles and different picking systems,the system picking efficiency of dual-command is better than that of single-command,and dual-command can improve the system efficiency by 5%-18% compared with single-command.Under different commands and different picking systems,the system efficiency under the classified storage strategy is better than that under the random storage strategy,and the system efficiency under the classified storage strategy can be improved by 15%?48%compared with the random storage strategy.Shuttle utilization under classified storage strategy is less than random storage strategy,and lift utilization is less than or equal to random storage strategy.In the planning and design of SBS/R-ROPS and E-SBS/R-ROPS,the research of this paper provides decision-making basis for determining the system configuration,such as the number of aisles,floors and columns of shelves,and the number of picking stations.In terms of operation optimization,it provides decision basis for determining the partition configuration and instruction mode of classified storage strategy.In terms of equipment integration,the company provides two solutions of shuttle vehicle and non-shuttle vehicle,which can provide decision-making basis for storage designers.