共查询到20条相似文献,搜索用时 31 毫秒
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针对多订单情况下多产品生产计划安排研究存在不足,提出了一种新的基于订单的计划排期多目标优化模型,目标包括利润最大化与均衡生产,通过各计划期之间产量安排对各资源消耗的偏差最小化来实现均衡生产.模型存在非线性多目标,实现时采用了遗传算法,通过Sheffield GATBX利用MATLAB编程实现. 相似文献
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基于均衡排产规则的钢管生产计划调度 总被引:1,自引:1,他引:1
针对钢管企业中管加工工厂生产计划调度的实际,以均衡排产规则为前提,在考虑生产连续、产线定修和前置库存的情况下,构建两层数学模型,分步骤地解决带有大规模柔性路径选择要求的多目标计划调度问题,并利用ILOG公司CPLEX软件包对其大规模的数据实例进行求解,该模型及求解思路可指导管加工工厂的实际生产计划调度,运用到软件开发中已取得良好的效果. 相似文献
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就生产而言,若能维持单品种长期生产,效率肯定是最高的,但考虑了市场因素以后,又是不现实的,因为生产必须随市场而动。如何更科学地编排每月的生产日计划并组织实施,尽量延长每台卷包设备生产同一品种或规格相似品种的时间,减少设备改动和换牌频次,同时又要满足上述市场的要求,这就需要在市场和生产效率间找到较佳的平衡点。 相似文献
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基于MCMC方法的连续时间SV模型建模研究 总被引:1,自引:0,他引:1
连续时间模型已被广泛地应用于资产定价中,但是它的参数估计仍存在许多困难.针对这一问题,利用基于Markov链的Monte Carlo模拟积分方法对连续时间的SV模型进行估计,选取上海股市的日综合指数进行实证研究,结果证明了所提模型和方法的有效性. 相似文献
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由于高科技公司具有类似买权的特性,如何对其进行价值评估是一个重要课题。文章以实物期权原理研究了高科技公司内在价值评估的基本方法,利用Schwartz和Moon提出的连续时间模型下的实物期权法来评估高科技公司价值,进行了实例分析,结果表明该方法有效。 相似文献
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给出装配时间如何分配给各工序的问题描述,针对该问题提出了三种建模方式,并针对不同的建模方式探导了相关算法.将物料需求计划分解、车间作业调度问题求解和网络计划三者从解决实际问题的角度联系起来,为求解装配工序时间优化问题提供了可以借鉴的思路. 相似文献
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现实的Jobshop生产环境中的生产日历和班次等把设备资源的有效工作时间段分割成离散状态。为了降低调度在确定工序开始和结束时间时的计算复杂性,提出了一种时间映射算法。通过该算法实现了离散作业时间到整数连续区间和整数连续区间到离散作业时间的快速转换;并以遗传调度算法为例,研究了时间映射算法与调度算法的融合技术,实现了在连续整数区间上的调度。研究结果表明,相比未采用时间映射算法的调度算法,采用时间映射算法能大幅降低调度在确定工序开始和结束时间上的计算复杂性,计算时间降幅达到39.7%,从而提高了调度的计算效率。 相似文献
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This paper describes the models, algorithms and implementation results of a computerised scheduling system for the steelmaking-continuous casting process of a steel plant in Austria. The basis for the scheduling task is a preliminary production schedule for the continuous casters (sequence of charges that must be consecutively cast and their allocation to the continuous casters). The scheduling task can be structured as four sub-problems: (1) scheduling the continuous casters. (2) Allocation of the charges to the parallel facilities at the upstream stages (converter and refining facilities). (3) Sequencing the charges at the converters and refining facilities. (4) Exact timing of all operations. The heuristic algorithm consists of three planning levels: (1) scheduling the continuous casters, considering the capacity restrictions at the upstream stages and the limited availability of hot metal. (2) Scheduling of the converter and refining facilities according to priorities, performing allocation and sequencing. (3) Improving the schedule by means of an LP model. The system visualises the schedules as Gantt charts. Extensive numerical tests with real-life data and more than two years of experience with the implementation demonstrate that the system produces reasonable schedules and is accepted by the planners. 相似文献
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Renato de Matta 《国际生产研究杂志》2018,56(19):6412-6429
This paper examines the scheduling of a drug packaging operation which requires assigning resources to production lines during set-up in order to satisfy product specifications. We present mixed integer programming models of the problem and develop a Lagrangian heuristic to solve the models. Real data from a drug company and randomly generated data are used to test the models. Results show the efficacy of our solution approach to find good feasible schedules. We discuss some of the practical benefits and potential issues about the production schedules obtained using the models. 相似文献
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SUN Rong-lei XIONG You-lun DU Run-sheng DING HanSchool of Mechanical Science Engineering Huazhong University of Science Technology Wuhan P. R. China 《国际设备工程与管理》2002,7(2)
Based on the concept of operation flexibility, we study the relationship amongmultiple operation sequences and provide a flexibility measure for operation sequences. Acriterion is proposed to prioritize each operation (rather than sequence). Under the multi-agentarchitecture the criterion can be used to guide the decision-making procedure during produc-tion scheduling so that there is an adequate flexibility at each decision point. Experimentalresults demonstrate the efficiency of the criterion when it is used as a scheduling heuristic.It can increase flexibility of manufacturing systems, and consequently improve the per-formance of the systems. 相似文献
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This paper studies an integrated scheduling problem for a single-item, make-to-order supply chain system consisting of one supplier, one capacitated transporter and one customer. Specifically, we assume the existence in the production stage of an intermediate inventory that works as a buffer to balance the production rate and the transportation speed. Jobs are first processed on a single machine in the production stage, and then delivered to the pre-specified customer by a capacitated vehicle in the delivery stage. Each job has a due date specified by the customer, and must be delivered to the customer before its due date. Moreover, it is assumed that a job that is finished before its departure date or arrives at the customer before its due date will incur a stage-dependent corresponding inventory cost (WIP inventory, finished-good inventory or customer inventory cost). The objective is to find a coordinated production and delivery schedule such that the sum of setup, delivery and inventory costs is minimised. We formulate the problem as a nonlinear model in a general way and provide some properties. We then derive a precise instance from the general model and develop a heuristic algorithm for solving this precise instance. In order to evaluate the performance of the heuristic algorithm, we propose a simple branch-and-bound (B&B) approach for small-size problems, and a lower bound based on the Lagrangian relaxation method for large-size problems. Computational experiments show that the heuristic algorithm performs well on randomly generated problems. 相似文献
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Nita P.A. Hidayat Andi Cakravastia T.M.A. Ari Samadhi Abdul Hakim Halim 《国际生产研究杂志》2016,54(4):1170-1185
This research addresses a batch scheduling problem for single item parts with multi due date on m heterogeneous batch processors. The objective is to minimise total actual flowtime of parts through the shop. The total actual flowtime of parts in a batch is the multiplication of the interval between batch arrival time and the due date by the number of parts in the batch. Using the actual flowtime as the objective means it is oriented to satisfy the due date as a commitment to customers, and simultaneously to minimise the length of time of the parts spending in the shop. An algorithm to solve this problem is proposed. 相似文献
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The heat-treatment operation in dynamic mould manufacturing often involves non-identical jobs, which allow for simultaneous processing yet with different weights and due dates. Effective production control of this operation is essential to improve the on-time delivery and decrease the manufacturing cost of the mould. This paper considers the dynamic control of a batch processor for dealing with such non-identical jobs. A new look-ahead batching strategy called MLAB (mould: look-ahead batching) has been proposed. In MLAB, the control decisions are made by the joint use of both near-future arrival information of upstream operations and workload level information of downstream operations. MLAB strategy is used to control two kinds of conflicting objectives related to the delivery and utilisation performances and finally achieve trade-off based on compromise programming method. Computational experiments are conducted to verify the effectiveness of the MLAB strategy and show that the results are promising as compared to benchmark control strategies. 相似文献
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In this paper, the problem of minimising maximum completion time on a single batch processing machine is studied. A batch processing is performed on a machine which can simultaneously process several jobs as a batch. The processing time of a batch is determined by the longest processing time of jobs in the batch. The batch processing machine problem is encountered in many manufacturing systems such as burn-in operations in the semiconductor industry and heat treatment operations in the metalworking industries. Heuristics are developed by iterative decomposition of a mixed integer programming model, modified from the successive knapsack problem by Ghazvini and Dupont (1998, Minimising mean flow times criteria on a single batch processing machine with non-identical jobs sizes. International Journal of Production Economics 55: 273–280) and the waste of batch clustering algorithm by Chen, Du, and Huang (2011, Scheduling a batch processing machine with non-identical job sizes: a clustering perspective. International Journal of Production Research 49 (19): 5755–5778). Experimental results show that the suggested heuristics produce high-quality solutions comparable to those of previous heuristics in a reasonable computation time. 相似文献