一种以减少能耗为目标的储位指派方法

在某些假设前提下,以一定时期内从某个储位取出某种品项人力所做的总功最小为目标,建立了人工拣货系统中简单往返拣货的线性规划模型,并用简单实用的密度-周转率索引算法来求解模型。理论证明密度-周转率索引算法所求解为模型的最优解。最后用算例验证了模型的有效性。     

基于COI与作业负荷平衡的多巷道仓库储位分配策略

储位分配策略直接影响仓储货品的拣选效率与仓库绩效。传统基于物料周转率(COI)的储位分配方法将出入库频率高的货物存储于距离出入口近的储位上,在多巷道分布的仓库当中,这可能导致部分巷道作业拥堵和事故发生率高等。为提升仓储货品拣选效率和减少巷道作业不平衡带来的负面影响,本研究将基于COI储位分配方法与巷道作业平衡改进策略相结合,通过定性解析与模型分析,提出绝对分巷道存储模型和相对平均与最大值控制模型两种储位分配改进方法。通过实例数据分析,两种新方案对行走距离增加值可控制于千分之一以内,而新最优可行解对完善仓储策略和进一步提升仓储企业效率有着重要作用。     

快速分拣区域储位空间分配策略对比分析

研究了快速分拣区域储位空间的优化分配策略,同时分析了企业常用的等时间分配策略和等空间分配策略的原理及模型。以某配送中心快速分拣区域为例,比较了3种储位分配策略的差别,验证了优化空间分配策略在节约补货成本方面的优越性。     

基于遗传算法的分区拣选系统储位优化实证研究

目的研究零售连锁企业区域配送中心分区拣选系统下的储位优化方法。方法以某药品连锁零售企业区域配送中心为研究对象,将不同分区的拣选时间趋于均衡作为储位优化目标,结合样本订单与历史订单的特点,建立储位优化数学模型,并采用遗传算法进行求解,以获取约束条件内该模型的最优解。结果在样本订单占80%权重的前提下,将所求得的分区与储位的解所对应的拣选时间,与研究对象的拣选现状进行对比,发现采用均衡各区拣选时间模型的求解结果提高了37.34%的效率,优化效果显著。结论实证研究证明了该模型和算法的有效性,该优化方法也广泛适用于其他分区拣选系统的储位分配作业。     

可移动货架下的储位选择与拣货路径联合优化

随着电商直播等在线模式的兴起，订单异质化加重，商品需求变化比以往更快。面对频繁变化的订单，许多电商仓库选择使用更加柔性的存储模式，如可移动货架，对仓库的存储布局进行快速调整，进而更好地进行拣货作业。针对分散存储策略和可移动货架下的订单拣货路径进行研究，提出一个包含储位选择与拣货路径的联合优化模型和货架移动优化模型的双层优化模型，设计一种双层元启发式算法框架，最后利用不同规模的数值实验对模型和算法的有效性进行验证。     

汽车零部件平准化拣配作业优化研究

针对汽车零部件拣配作业工作效率低、工作负荷不均衡及配送车辆装载率低的问题,以作业人员工作负荷均衡化和配送车辆装载率最大化为目标,建立汽车零部件平准化拣配作业优化模型.模型求解过程分为两级:运用启发式算法确定动态作业人员分配方案;在作业人员合理分配基础上利用遗传算法确定换装顺序及车辆装载计划.实例分析结果显示,与原拣配作业方案相比,该模型使车辆装载率提高了18.4%,作业总工时减少了26 h.     

某公司仓库储区和货位的分析与改进

针对某公司仓储管理中储位管理存在的问题,对该公司的储区和货位进行了分析,提出了动静储区分区的改进方案,分区后总行走时间减少了近61%.此外,还对动储区建立整数线性规划模型,以作业人员行走时间最短为目标,进行了优化,给出动储区具体货位分配方案.     

基于荷兰式拍卖机制的RMFS货位指派研究

目的对移动机器人拣货系统(RMFS)的货位指派问题进行研究,提出基于荷兰式拍卖机制的货位指派模型来提高RMFS的拣货效率。方法构建荷兰式拍卖模型并按周转率对指定区域的SKU进行逐步调整,以货位指派匹配度为期望指标,实现SKU的需求模式与仓库存储结构之间的合理匹配。结果通过与随机指派模型对比发现,在不同仓库规模、需求偏度、订单规模等情况下,基于荷兰式拍卖的货位指派方法可以使拣货路程下降21.15%、工作时间平均下降20.57%左右。结论与传统指派方法相比,提出的货位指派模型可以大幅度降低RMFS系统的拣货距离和时间,大幅度提升在线零售企业的RMFS的拣货效率。     

新型无人仓AutoStore的货物合箱方法研究

目的 为减少AutoStore系统在共同存储策略下的订单处理时间,解决经营品类繁多,但仓储面积有限的企业货物存储问题。方法 提出货物合箱的存储方法,设计关联规则挖掘算法与混沌种子优化算法的混合优化算法进行求解。从机器人翻箱操作、料箱的分配规则、系统布局三方面进行分析,结合AutoStore运作规律,建立以机器人拣货行走距离最短为目标函数的数学模型,通过Apriori算法输出货物热度,输入混沌种子算法,得到储位分配结果,实现联动决策。在基本种子算法的迭代中加入混沌序列,帮助种子避开局部极小值。结果 实例分析表明,货物合箱方法能够显著减少共同存储下AutoStore系统的订单处理时间,缩小与指定存储策略订单处理时间的差距,与粒子群算法和基本种子优化算法相比,混沌种子优化算法的优化效率更高、稳定性更好。结论 文中的研究为经营品类繁多,但仓储面积有限的企业提供了一种更适合的货物存储策略,具有较强的操作性和实际意义。     

收益共享契约下的供应链订购决策分析

以制造商、分销商和零售商组成的供应链为研究对象,以系统的全局协调和完美协调为目标,研究了收益共享策略下的订购决策.分别建立了缔结收益共享契约模式下各节点企业的收益模型,提出实现系统全局协调的订购决策及系统实现完美协调的条件,得出全局协调的实现取决于零售商的订购决策、批发价格和利润分割系数,以及该模型在高风险市场下更加有效的结论.     

基于数据挖掘的动态货位指派系统

目的为提高需求快速变化、波动较大的在线零售企业的仓库货位优化效率。方法利用数据仓库和数据挖掘法,研究基于复合规则的动态货位指派策略。对该货位指派的数据集成分析、指标计算、规则生成和货位指派等4个模块进行分析,并设计库区标定算法和规则生成算法来生成货位指派规则集。结果基于复合规则动态货位指派不仅能够节约拣货距离,而且拣货效率受需求变化的影响非常小。结论数值实验表明,与传统的货位指派策略相比,基于复合规则动态货位的指派系统可以得到更好的结果,并且在平均订单规模较大和需求偏度大的情况下效果更加明显。     

Response to Al-Hakim's note

Storage location assignment and interleaving policy are two closely related problems in warehousing management. This paper addresses the location assignment and interleaving problem at the same time in an automated storage/retrieval system with duration-of-stay based shared storage policy. Based on the heuristics for single command operation, a two-step procedure is developed to solve the problem. A tabu search algorithm is proposed to improve the solution for medium and large sized problems. The computational results indicate that the tabu search algorithm is effective in finding high quality solutions, and efficient in solving large sized problems.     

基于英式拍卖的RMFS货位指派研究

目的 构建英式拍卖模型，以待指派商品品项(SKU)群的最低周转率为媒介，通过逐步提升最低周转率来实现待指派SKU与待指派区域货位数量的匹配。方法 针对移动机器人拣货系统(RMFS)中的货位指派，提出基于英式拍卖机制的货位指派方法，提升仓库拣货效率。结果 与随机指派相比，在不同仓库规模、订单规模、订单偏度的RMFS中采用英式拍卖货位指派机制，机器人行走路程下降比率在大型仓库中达30.17%，中型仓库的下降比率为27.31%，小型仓库的下降比率为24.13%。结论 采用英式拍卖机制在RFMS中进行货位指派可大幅度提高工作效率。     

An integrated materials handling model for machine location in existing facilities

A machine location criterion is proposed for situations where machines must be located in existing facilities to manufacture new products. The location criterion is based on a measure of materials handling service. It is applicable when an existing, automated materials handling system is fully integrated within an existing manufacturing facility. The service level is measured by the expected rate of unsuccessful load transfers associated with a fixed production schedule, handling system, and assignment of machines to locations in a facility. An analytical model focused on the interfaces of automated materials handling systems is formulated to predict the corresponding service level associated with alternative machine locations in an existing facility. The model is illustrated through a sample problem which demonstrates how the specific operating characteristics of a typical automated materials handling system can be modelled to predict handling performance for alternative machine locations.     

Simulation study of an automated storage/retrieval system

In this paper we present a simulation study of an automated storage/retrieval system and examine a wide variety of control policies. We compare several storage location assignment policies. For the class-based storage policy, we apply a recent algorithm that enables us to evaluate the trade-off between storage space requirements and travel times. We also study a new storage location policy which combines low storage space requirements with short mean travel times. Furthermore, we study the sequencing of storage and retrieval requests whereby we focus on the trade-off between efficient travel of the S/R machines and response time performance.     

Location and layout planning

This paper gives a review on quantitative methods for microeconomic location planning which can be subdivided into facility location and layout planning. Depending on different objectives and restrictions, there is a large variety of problems, especially in the field of facility location planning. Basic models arising in discrete and continuous facility location planning (e.g., warehouse location, center, location routing, competitive location problems), as well as corresponding solution methods, are presented. Generalized models and recent developments in these fields are outlined. Within layout planning, the quadratic assignment problem and graph-theoretic concepts are considered.     

Single machine due-window assignment scheduling with resource-dependent processing times to minimise total resource consumption cost

This paper considers a single-machine scheduling problem involving convex resource-dependent processing times and due-window assignment simultaneously. The goal is to minimise the total resource consumption cost under the constraint that the schedule cost involving earliness, tardiness, window location, window size and makespan does not exceed a given limit for two popular due window assignment methods: the common flow allowance (slack) due window assignment method (referred to SLKW) and the common due window assignment method (referred to CONW). We show that the problem can be solved in polynomial time. Some extensions of the problem are also given.     

A reconfiguration of fire station and fleet locations for the Santiago Fire Department

The geographical distribution of the population of the city of Santiago, Chile, has changed significantly in recent years. In spite of this fact, the location of the fire stations has remained unchanged. We propose a model for the optimal location of the fire stations and a fleet assignment for the Santiago Fire Department (SFD), aimed at maximising the number of events attended to with a predefined standard response. The results of the model are compared with respect to the current location of fire stations and fleet assignment in the SFD. There are different types of resources (stations and vehicles), and different types of events in which the same types of vehicles are used. We analyse various possible current and future scenarios, using a forecast based on historical data. Our results show that by optimally reallocating the resources a 10–30% increase can be achieved in the number of emergency calls that are attended to with an adequate response in time and number of vehicles, without the need for additional fire stations or vehicles. Thus our contribution is empirical and relies on the real world application which is being considered by Chilean government.     

Due-window assignment and scheduling with general position-dependent processing times involving a deteriorating and compressible maintenance activity

In this paper, we consider common due-window assignment and scheduling problems with general position-dependent processing times involving deteriorating and compressible maintenance activity on a single machine. Two models associated with maintenance activity are examined in this article, in which the maintenance length is assumed to be either time-dependent and compressible or position-dependent and compressible. The objective is to find jointly the location and size of due-window, position of maintenance as well as resource amount allocated to it, and job sequence to minimise a total cost function based on earliness, tardiness, window location, window size and resource cost. We show that the problem considered in each of the two models’ setting can be optimally solved with polynomial time algorithm by reducing to assignment problem. Finally, two examples are provided to illustrate the solution procedures.