质疑"佳能革命"

从1998年开始,日本佳能公司将数码相机和彩色复印机等设备的生产从国外转回日本,并以一种区别于传统流水线生产的方式组织生产。在这种被称为“单元生产模式”的生产方式中,劳动者不是被固定在生产线的某个环节从事某个零部件的安装,而是在同一位置上组装完成一件完整的产品。在这一生产方式下,一件完整的产成品不是通过所有劳动者的配合来完成,而是由几个劳动者(小团体或小单元)甚至一个劳动者来完成。与其他日本企业纷纷到发展中国家投资设厂、以流水线模式组织生产、充分利用东     

面向并行制造的多生产单元协同调度研究

为提升多生产单元制造系统整体效率，在其系统内开展面向并行制造的协同调度研究，在考虑运输、换线等时间的基础上，构建多生产单元并行协同调度模型，采用并行分段协同遗传算法求解；在此基础上，将所研究协同调度方法应用于某复杂机电产品多生产单元制造车间，并与变批量调度与等批量调度比较。研究表明，所提的并行协同调度方法可以显著提升生产单元效率，提高生产单元设备和人员利用率。     

基于智能优化的钢铁生产计划与调度研究

钢铁工业是工业经济中的重要基础工业,它能够为建筑、汽车、机械和其它工业提供基本原材料,因此钢铁工业也是工业经济的实质和主要部分.虽然有效的钢铁生产计划与调度对于降低成本和能源消耗的重要性不比其它工业弱.但是钢铁生产计划与调度研究还没有引起生产和作业管理研究者象对待机械和电子工业一样的广泛重视.与机械制造业相比,钢铁生产计划与调度由于存在工件成组和优先级约束、以及工件高温引起的高等待费用等特征.这些特征进一步增加了钢铁生产计划与调度的难度.本文综述了我们在钢铁生产计划与调度的理论与方法方面的研究成果,主要目的是在这个有希望的领域刺激更多的研究.     

会计电算化对企业信息化的新启示

一、会计电算化是企业信息化的重要组成部分企业信息化的基础首先是实现生产过程的自动化,即通过电子和信息技术实现对生产过程的设计、制造、评测和控制的自动化。为此企业采用了计算机辅助设计(CAD)、计算机辅助制造(CAM)以及其他自动控制技术来控制设计和生产过程,以提高职工的工作效率和提高产品的质量;企业信息化的另一个目标是实现整个企业计划、财务、人事、物资、管理等方面的管理自动化,并通过Intranet实现企业内部信息交流的畅通,达到了信息流、资金流与物流的整合。为此企业要建立管理信息系统(MIS)、决策支持系统(DSS)、…     

基于混合流水作业组织的集装箱码头装卸作业集成调度优化

集装箱码头集疏运资源调度的对象是由岸桥、集卡、场桥所构成的多阶段一体化的集装箱装、卸、运操作系统,将该系统的调度优化基于多阶段混合流水线调度问题建立混合整数规划模型,同时考虑集装箱码头现实作业中预定义顺序、避免岸桥交叉作业、以及取决于作业顺序的切换时间等现实约束,针对问题自身的特点设计了两阶段启发式算法,得出各阶段设备的指派结果及作业顺序。通过与基于现行调度规则的调度方案以及与目标函数理论下界值的对比实验,显示了所提出的集成调度模型及求解算法能够有效降低船舶在港时间并实现集卡资源的共享,为集装箱码头集疏运资源的集成调度提供了新的思路。     

军用电子装备企业生产计划管理模式探索与应用

为了进一步解决国内军用电子装备企业生产计划管理模式中存在的各种问题,有必要探索出一种最适合的军用电子装备企业的生产计划管理模式。为此,本文结合军用电子装备企业的生产特点,并以项目管理、OPT和MRP为理论依据,基于动态调度的方法,提出一种全新的生产计划管理模式,即网络计划+MRP+动态调度的"三纵三横"管理模式,该模式最大的特点是能够对企业生产计划进行分层集成控制,它的应用将会使军用电子装备企业当前生产计划管理模式中存在的问题获得有效解决。     

集成电路板组装系统优化问题及其研究动态

集成电路组装是将电子元器件安装在集成电路板上,从而实现电子元器件的互联的过程,是电子信息行业的基础产业.本文将集成电路板组装系统优化问题划分为四个子问题组装顺序优化问题、部品指派优化问题、组装模式优化问题以及组装线平衡优化问题.重点介绍了其中的前三类子问题的优化模型及优化算法.并通过一个应用实例说明了模型及其算法的有效性.在此基础上,提出了今后对第四类子问题的研究方向与思路.     

网络对制造企业传统销售流程的影响

制造企业的生产类型 制造企业是指从事有形产品的生产、加工、装配和销售的企业。根据不同的划分标准，制造企业有很多种类，其中一种就是根据企业生产工艺过程的特点分为离散型和流程型。离散型制造企业是指生产工艺过程不连续，采取零部件组装方式生产，     

电子产品制造企业MES的功能设计

作为生产管理系统核心的MES是生产企业过程自动化系统与管理信息系统之间的桥梁,同相关系统之间存在密切的数据交流关系,制造执行系统的功能设计是建立高质量制造执行系统的基础。本文在分析了电子制造企业的生产流程特点的基础上,设计了针对电子制造企业的制造执行系统的功能模块,这些功能模块体现了电子制造业对制造执行系统的功能要求。     

服装智能化流水线研发与产业化

服装生产流水线的形式是随服装产品种类的不同、生产的批量不同和生产的时间限制不同而变化的。为了达到高效率的生产,必须对服装生产流水线进行生产平衡调控,对专业化程度和劳动力成本作必要的调整处理,提高产品质量,提高劳动生产率,从而提高企业的经济效益。论文重点探讨了服装智能化流水线研发与产业化,以便对服装生产提供相关的借鉴。     

基于DNA遗传算法的表面贴装生产线负荷优化分配

印制电路板组装任务的负荷优化分配包含设备约束、工艺约束等大量约束,是电子行业表面贴装生产线中的一类重要优化问题。其优化目标是在生产节拍给定和一定约束条件下,使得不同贴装机负荷均衡,任务分配达到最优。首先,根据不同表面贴装机、不同吸嘴及多种类型元件匹配的的复杂性,提出贴装机任务分配组合优化的问题;然后分析设备和元件的参数、组装可行性、贴装时间,以及贴装优化关系等因素,并提出假设条件,建立了平衡率最大化条件下的负荷分配组合优化的数学模型;最后,针对贴装生产线负荷分配问题的复杂性与特殊性,通过改良编码方式后的DNA遗传算法来优化组合数学模型,计算适应度,并借助MATLAB进行仿真求解,进而找到最优解。结果表明：本文提出的贴装生产线负荷分配方法可以解决带复杂约束的印制电路板组装负荷优化分配问题,提高设备的平衡率和生产效率,促进生产线的优化运行。     

Two-sided assembly line balancing: A genetic algorithm approach

A two-sided assembly line balancing problem is typically found in plants producing large-sized high-volume products, e.g. buses and trucks. The features specific to the assembly line are described in this paper, which are associated with those of: (i) two-sided assembly lines; (ii) positional constraints; and (iii) balancing at the operational time. There exists a large amount of literature in the area of line balancing, whereby it has mostly dealt with one-sided assembly lines. A new genetic algorithm is developed to solve the problem, and its applicability and extensibility are discussed. A genetic encoding and decoding scheme, and genetic operators suitable for the problem are devised. This is particularly emphasized using problem-specific information to enhance the performance of the genetic algorithm (GA). The proposed GA has a strength that it is flexible in solving various types of assembly line balancing problems. An experiment is carried out to verify the performance of the GA, and the results are reported.     

Line balance analyses for system assembly lines in an electronic plant

This research analysed and optimised the assembly line balance of notebook computer system production lines in a major computer plant. The research developed a mathematical model for balancing assembly lines of a specific notebook computer system. Precedence relationship charts were created to enforce the required sequences and ILOG CPLEX software was used to obtain the optimal solution of the task assignments to the workstations. The new task assignments were simulated to verify the improvement recommendations and predict the potential benefits.The estimated improvements include: (1) 5.9% increase in average daily production; (2) 29% decrease in average daily WIP; (3) 67.9% reduction in cycle time; (4) 16.7% reduction in operator headcount over the whole system assembly area. The contributions of this research include: (1) Establishing line balancing mathematical model suitable for notebook computer factories; (2) Optimising the system assembly lines for the subject company; (3) Transferring the line balance modelling and optimisation techniques for company use.     

Job route selection model for workload balancing between workstations in flexible flow line

A flexible flow line (FFL) consists of several groups of identical machines. All work-orders flow along the same path through successive machine groups. Thus, the balancing of workloads between machine groups in order to maximize total productivity is emphasized. On the other hand, many different types of work-orders, in varying batch or lot sizes, are produced simultaneously. The mix of work-orders, their lot sizes, and the sequence in which they are produced affect the workload. However, the work-orders and their lot sizes are pre-fixed and cannot be changed. Because of these reasons, an optimal route selection model has been developed using heuristic search and a min-max algorithm for balancing the workload between machine groups in the FFL.     

Job sequencing and component set-up on a surface mount placement machine

In this paper, the problem of sequencing PCB assembly jobs on an automatic SMD placement machine is addressed. The objective is to minimize the makespan. Moreover, both the job arrival times and the precedence constraints for those jobs requiring component placement on the primary and secondary side of the same board must be taken into account. A considerable set-up time occurs when switching from one board type to another, which depends on the number of component feeders to be replaced in the magazine of the assembly machine. The exchange of component feeders is complicated by the fact that each feeder occupies a different number of magazine positions. Theoretically, the minimum makespan required for a given batch of jobs could be derived by solving the order sequencing and the component set-up problems simultaneously. However, optimal solutions are practically unattainable for problems of realistic size. Therefore, efficient heuristic solution procedures are developed which exploit component commonality between PCB types. The numerical results obtained indicate the practicality of the proposed heuristics in an industrial application.     

THE EFFECT OF LEARNING ON THE OPERATION OF MIXED-MODEL ASSEMBLY LINES

The common approach to balancing mixed-model assembly lines assumes that the line operators are well trained and that the learning effect is negligible. The assumption is that the line operates in steady state over a long period of time. Time-based competition and frequent design changes in many products make this assumption incorrect, and the effect of learning on mixed-model lines should not be neglected. We defined start-up period and developed a model for the line design during start-up. It can be used to evaluate a proposed line design or to develop a feasible line design and to estimate its cost. This proposed model integrates mixed-model learning curves with aggregate planning under learning and a mixed-model line design into a comprehensive framework designed to minimize the total cost of the line during the start-up period.     

PCB assembly scheduling through kit concept

This paper presents the design and test of a new scheduling environment dedicated to the off-line scheduling of PCB assembly shops. The main idea introduced is the employment of the 'kit concept' as a scheduling tool, as opposed to the traditional batch scheduling. In the kit approach, the basic PCB aggregations are kits composed of different PCBs matching finished products requirements, instead of homogeneous batches of identical boards. By introducing the kit approach, PCB assembly schedule is intended to be focused more towards the assembly of final products than towards the internal PCB assembly shop constraints and requirements. A simulation model and data from a real assembly system are used to compare the kit approach with traditional batch processing. Experimental results show that the proposed kit approach jointly achieves remarkable improvements in the effectiveness and efficiency performances of the assembly system, as compared to the batch approach. However, it is determined also that these advantages can only be achieved if a sufficiently advanced scheduling system is used.     

A multiobjective model and evolutionary algorithms for robust time and space assembly line balancing under uncertain demand

Changes in demand when manufacturing different products require an optimization model that includes robustness in its definition and methods to deal with it. In this work we propose the r-TSALBP, a multiobjective model for assembly line balancing to search for the most robust line configurations when demand changes. The robust model definition considers a set of demand scenarios and presents temporal and spatial overloads of the stations in the assembly line of the products to be assembled. We present two multiobjective evolutionary algorithms to deal with one of the r-TSALBP variants. The first algorithm uses an additional objective to evaluate the robustness of the solutions. The second algorithm employs a novel adaptive method to evolve separate populations of robust and non-robust solutions during the search. Results show the improvements of using robustness information during the search and the outstanding behavior of the adaptive evolutionary algorithm for solving the problem. Finally, we analyze the managerial impacts of considering the r-TSALBP model for the different organization departments by exploiting the values of the robustness metrics.     

A genetic algorithm for assembly line balancing

Assembly line balancing is a very important aspect in any mass production setup. However, finding the optimal balance is a very difficult proposition because of the computational complexity involved. Hence sub-optimal solutions are preferred over optimal solutions. In this work, a genetic algorithm (GA) is presented for obtaining good quality solutions for assembly line balancing problems. A major feature of GA is the ability to take care of a variety of objective functions. A modified GA working with two populations, one of which allows infeasible solutions, and exchange of specimens at regular intervals is proposed for handling irregular search spaces. The experimental results obtained with a single population, as well as two populations are encouraging.     

Production planning of mixed-model assembly lines: a heuristic mixed integer programming based approach

Process technology capabilities are becoming increasingly important as flexible manufacturing continues to be more prevalent, and as competition compels companies to provide expanded variety, at ever lower cost, so introducing plant and processes technological constraints. Model flexibility can also benefit from an appropriate production planning process, especially concerning mixed-model assembly lines, since it can facilitate master scheduling and line balancing activities, which are essential aspects of flexibility. Robust and practical planning approaches have to take into account two different aspects: the first consists in ensuring that the elaborated aggregate plan can be disaggregated into at least one detailed feasible plan for the realised demand, whereas the second in ensuring that this detailed plan is feasible at the operational level. This article faces the model flexibility challenge, reviewing and discussing the planning problem of a real world assembly manufacturing system, producing high volume and a variety of agricultural tractors and machines, analysing and resolving some important issues related to technological, organisational and managerial constraints. This article illustrates the implementation of an Advanced Planning System integrated with a mixed integer-programming model, which is solved by a new iterative heuristic approach capable of achieving interesting planning improvements for model-flexibility management.