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1.
带时间窗的汽车总装线物料配送路径规划 总被引:1,自引:0,他引:1
分析了现阶段汽车总装线物料配送中存在的问题,建立了适用于汽车总装线物料配送路径规划的混合时间窗模型,提出了解决带时间窗的汽车总装线物料配送路径优化问题的改进遗传算法,使用了一种新的染色体编码方式和与之对应的交叉算子。针对传统轮盘赌随机操作选择误差比较大的弊端,提出改进的轮盘赌选择算子,加大随机数的产生次数并加入排序选择的思想,融合了最佳个体保存选择策略,提高算子的选优性能。实验表明该算法用于求解带时间窗的汽车总装线物料配送路径问题的有效性。 相似文献
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Veronique Limère Hendrik Van Landeghem Marc Goetschalckx El-Houssaine Aghezzaf Leon F. McGinnis 《国际生产研究杂志》2013,51(15):4046-4060
In a synchronous and fast-paced assembly line operation, it is crucial that the right parts are being supplied at the right time and at the right place. In automotive assembly, the need for efficient material handling part delivery is particularly great because of extensive product customisation and the lack of space to stock all the required parts at the assembly line. This paper introduces a mathematical cost model for evaluating the assignment of parts to one of two possible material supply systems: kitting or line stocking. Case data from an automotive company in Belgium is used to test the model. The results demonstrate that hybrid policies, where some parts will be kitted while others will be stocked in bulk at the line, are preferred to the exclusive use of either material delivery system. The factors influencing the preferred delivery method for individual parts are explored. Numerical results are presented. 相似文献
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This paper studies the problem of scheduling a multiple-load carrier subject to last-in-first-out loading constraints in an automobile assembly line. Two scheduling criteria, the throughput of the assembly line and the material handling distance, are considered in order to maximise the profit of the assembly line. Different from other studies, the product mix and weights of the scheduling criteria are considered to be variable. A scheduling approach is proposed for the problem. At moments when the product mix or weights of the scheduling criteria change, the scheduling approach can select an appropriate rule from a set of given rules. In this study, the proposed approach is compared with other approaches by simulation in order to verify the performance of the proposed approach. The results indicate that, when the product mix and weights of the scheduling criteria are variable, the proposed scheduling approach outperforms other approaches. 相似文献
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A mixed-model assembly line is commonly used in the automobile industry. When there are multiple departments on an assembly line, there are usually different sequencing considerations from various departments. Intentional sequence alteration to accommodate a different sequencing consideration can be needed for a downstream department. Unintentional sequence alteration may also take place due to rework or equipment breakdowns. There is also an increasingly common practice in automobile assembly to have parts sequenced before delivering to the final assembly line. To achieve sequenced parts delivery, the sequence needs to be known in advance. Thus, addressing sequence alteration and restoration becomes more relevant for an automobile mixed-model assembly line. A number of sequence alteration methods to accommodate a downstream department's sequencing considerations are presented. One method easily supports sequence restoration of the sequence altered by the method. Two sequence restoration methods for restoring the sequence altered by unintentional reasons are discussed; the proper sizing of the two restoration methods are also addressed. These sequence alteration and restoration approaches mainly address the design and control aspects of the mixed-model assembly line. A case study based on an automobile assembly plant is presented to demonstrate the use of these methods. 相似文献
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Order-oriented products assembly sequence among different assembly lines becomes a critical problem for mass customisation manufacturing systems. It significantly affects system productivity, delivery time, and manufacturing cost. In this paper, we propose a new approach to extend the traditional products sequencing from mixed model assembly line (MMAL) to multi-mixed model assembly lines (MMMALs) to obtain the optimal assembly sequence with the objectives of minimising consumption waviness of each material in the lines, assembly line setup cost, and lead-time. A multi-objective optimisation algorithm based on variable neighbourhood search methods (VNS) is developed. We perform an industrial case study in order to demonstrate the practicality and effectiveness of the proposed approach. 相似文献
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This paper considers the material supply problem for aircraft moving assembly lines. Distinguished from general automobile assembly lines, multiple parallel jobs are assembled concurrently and durations of assembly jobs are quite long, thus amounts of materials are orderly stored at the line-side space at the same time. In addition, the line-side space should be reused in the time dimension. With these characteristics, decisions on line-side storage of materials were introduced on the basis of material batching and tow-trains scheduling problems. An integrated decision–making mathematical model with the objective of minimising the number of deliveries was established. A hybrid endocrine-immune algorithm (HEIA) was proposed to jointly make decisions on the delivery batch, delivery time and storage positions of each job’s materials. Numerical experiments with the real-world data and randomly generated instances validate the effectiveness and efficiency of HEIA. 相似文献
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Henry Aigbedo 《国际生产研究杂志》2013,51(2):417-430
Metrics used to assess level parts usage for some JIT supply chains are based on the product-unit by product-unit launch of products on the assembly line. However, many automobile assembly plants require parts suppliers to deliver parts to the assembly line by using a constant order cycle, non-constant order quantity framework. The paper proposes metrics that are suited to this parts delivery framework. Through extensive simulation over a wide range of assembly parameter values, it assesses the ability of supplier plants to match assembly requirements at each supply epoch. Among other things, the study finds that the conventional JIT scheduling framework also works well in general under this parts delivery arrangement, but acute parts stockout conditions could sometimes occur. Therefore, managers need to consider this in determining appropriate inventory levels for each part. This will prevent stockouts and reduce supply chain costs. 相似文献
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通过对某汽车主机厂的工厂物流系统进行实地考察,运用流程作业分析方法,剖析了准时生产环境下工厂物流作业组织和流程。根据物流各环节工时消耗规律,基于生产计划、零部件需求、零部件包装体积和作业参数及工序建立了面向混流汽车生产线的物流能力需求与平衡的数学模型,为合理地测算物流系统工时及设备需求,量化物流劳动强度,平衡系统内各部分物流能力,提供了较为科学的方法。算例表明,建立的数学模型是正确并有效的,可为实际应用提供指导。 相似文献
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Many complex assembly lines, such as those in the automobile industry, have dozens or hundreds of stations that are affected by customer-selected options on the jobs being assembled. The various options often require significantly different amounts of processing time, and the role of assembly line sequencing in this context is to smooth out the flow of work to each station. However, most assembly line sequencing algorithms developed for such situations cannot consider so many stations or options effectively. In this paper, we develop an analytical method to compute a criticality index for each station, which can be used to determine which stations are most important to include in an assembly line sequencing algorithm. We report computational results using actual industry data which indicates that substantial improvements can be obtained by selecting stations based upon this criticality index. 相似文献
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对S公司的服装缝制流水线编排情况进行研究,建立了基于ProModel的仿真模型.将仿真模型运行情况与实际情况进行对比,确定模型的有效性,并运用该模型运行结果分析实际流水线生产情况,有针对性地提出改进措施并仿真,根据仿真结果对流水线进行了优化.结果表明,在考虑和处理诸如回修、搬运等因素的影响时,仿真方法相比手工编制方法具有明显的优势,有利于企业更有效地提高流水线的生产效率和实现对生产进度的准确把握. 相似文献
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In this paper, an approach is proposed that verifies the controller logic processes for the automobile industry via simulation. For this purpose, a state-based object model that creates a virtual car body assembly line is proposed and a verification methodology using observed signal sequences during the simulation is proposed. This approach was applied to an assembly line controlled by a PLC and the effectiveness of the proposed system was explained in a case study. 相似文献
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This paper proposes an efficient vehicle dispatching rule which minimises the vehicle blocking and delivery times in automatic material handling systems of 300 mm semiconductor manufacturing. In order to evaluate the performance of the proposed dispatching method, discrete event simulation models were developed. The results show that the proposed method has a significant impact on average delivery time, throughput and vehicle utilisation. In particular, it reduces the variance of the delivery time remarkably. 相似文献
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Mixed-model assembly nowadays is a common practice in the automobile industry. In an automobile assembly plant, many car options often need to be considered in sequencing an assembly line, for example, the multiple sequencing objectives that consider a pattern, blocking, spacing, and smoothing of options. A general heuristic procedure is developed in this paper for sequencing automobile assembly lines considering multiple options. The procedure obtains an initial sequence by an enhanced constructive procedure, swaps orders for the most deteriorating category of objectives, and performs re-sequencing attempting to improve the swapped sequence. The heuristic procedure was shown to frequently improve the initial sequences by swapping and re-sequencing when swapping opportunities exist. A further improvement step is also proposed to perform a limited search based on the swapped solution. The limited-search improvement step was shown to be effective in further improving solutions from the heuristic procedure in the computational experimentation. Solutions from the heuristic procedure in conjunction with the limited-search improvement step were compared to those from the simulated annealing procedure for large-size problems and showed relatively positive results. 相似文献
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针对温州汽配企业遭遇的效率低下、人力成本上升困境,以某汽配企业组合开关装配线为研究对象,在运用秒表测时法测定装配线各工位作业时间的基础上,通过双手作业分析、工装夹具设计、工作台布局设计、工位重划分等方法,以及流水线平衡设计理论对原有流水线进行了平衡改善设计.通过改善,单件作业时间降低了14.6%,生产线平衡率提升了13.6%,人均产量提升了39.3%,同时作业环境及员工工作疲劳度也得到了很大的改善. 相似文献
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J. M. A. Tanchoco 《国际生产研究杂志》2013,51(5):1041-1062
This paper introduces a facility layout design procedure for converting an existing manufacturing system with a predefined aisle structure to a cellular manufacturing system based on the 'segmented flow topology' (SFT) developed by Sinriech and Tanchoco. The proposed procedure is aimed at finding the best machine grouping, along with the locations of pick-up and delivery stations and machine layout for each cell based on an existing facility. The objective is to minimize the total material handling cost. In contrast to previous work in this area, the proposed design procedure takes into account both distance and material flow in forming machine clusters. In addition, a revised cost model for material handling system, which accounts for different aspects of capital and operating cost, is presented. 相似文献
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This paper addresses the design of an assembly system facility consisting of multiple assembly lines of different shapes. In such a design problem there are two conflicting objectives: (i) to minimize the overall area of the facility; and (ii) to maximize the efficiency of the material handling transportation system. We first address the optimization problem of objective (ii) when replacing objective (i) with a constraint on the facility area. We propose a mixed-integer linear program to determine the layout of a facility with given dimensions and with given assembly line areas and shapes (that cannot be changed due to technological considerations). In the layout model, the physical placement of each line within the facility is a decision variable. The objective function of the layout model is to minimize the distances traveled by material flow. Our performance analysis provides an indication of the maximal problem size that can be solved in a reasonable amount of time and we examine the effect of the problem parameters on the solution run time. This layout model is then incorporated into an efficiency frontier approach for facility design to address both objectives. Examples are presented to illustrate the use of the proposed facility design model. 相似文献