某钢铁企业精益策略解决多机排产转运问题

以某钢铁加工企业多机连续生产为研究对象,针对在制品多、过程周期长的问题,应用精益方法对计划、调度和操作作业进行改善,实现多机生产均衡化及物料同期化,降低了在制品数量和过程周期时间.为保证生产准时化运行,对现场进行作业改善及目视化.实施改善方案后,该工厂的在制品库存降低33％,变质损失成本减少为0.     

精益生产在企业厂内物流改进中的应用研究

厂内物流贯穿于企业的整个生产过程,是精益生产的有机组成部分,并且厂内物流在生产系统的设计过程中处于战略的高度.本文结合我公司推进精益生产4年来的实际生产经验,通过对LC公司厂内物流现状分析和改善的实例,希望能给国内的企业推进TPS,改善物流,节约生产成本提供一些好的思路和方法.     

流程工业在制品库存的分段控制方法

从分析流程工业生产特点和ERP系统的在制品库存管理方法着手,结合准时生产制(JIT)和大规模定制思想,从稳定生产过程的角度探讨流程工业在制品库存控制的改善和优化问题.提出采用计划下达点和定制点作为过程分离点和关键控制点来对整个生产过程进行分段控制的两点控制方法,从而简化了控制过程,在很大程度上克服了流程工业难以精确控制的矛盾,使生产过程更顺畅,在制品库存量更合理.     

基于价值流的汽车座椅滑轨生产线分析与改善

以华瑞汽车座椅滑轨生产线为例,论述了应用价值流图技术进行生产现场系统改善的过程.首先根据该厂生产线现状和价值流图的符号,以可视化的方式描述生产线的现状,然后结合工业工程的基本分析方法,找出了该厂生产线中所存在的设施布置、搬运、等待、设备不足等制约产能的瓶颈问题,区分了生产中的增值和非增值的环节.最后寻找消除这些浪费环节的方法,对生产线按精益原则布置,绘制出了未来状态图,帮助管理者准确地拟定未来的改善方案.通过生产过程的实施带来产能和经济效益显著变化.     

空调生产中的价值流分析及其改善

美的集团在现有空调生产过程中引入价值流管理.在实施过程中同时结合动作分析.SOE分析以识别现有价值流中的增值和非增值环节,进而基于5W1H、ECRS原则对现有生产线进行平衡、改善.最终形成价值流创新方案.经实测比较:目标生产线改善后生产效率提高50%.周期缩短2377S.能满足现有市场需求.     

基于JIT的某饲料厂排产方法研究

以某饲料厂的连续性生产过程为研究对象,针对缺货率高和库存量较大的问题,提出基于JIT的精益改善方案.通过引入看板、PQ分析、帕累托图和生产原单位等工具对排产过程进行改善,采用定时不定量与定量不定时结合的定定排产方式,定定排产方式使该厂的缺货率由每月的33％降低为10％,库存量由日销量的2.2倍降低为1.5倍.     

PLC厂Cell生产线改善案例

通过对PLC厂插件段生产效率分析,提出改善线体、导入Cell生产方式是提高生产效率的关键,以作业测定为依据,结合IE生产线平衡改善手法并作相应的Cell化布局,以实例说明改善前后的生产效率情况,充分证明了PLC厂Cell生产线改善的可行性、有效性,对电子厂实施精益生产有很强的借鉴作用,指出Cell生产方式应用过程中应注意的事项.     

基于EVSM及仿真技术的精益生产改善研究

构建了环境价值流图分析法,使价值流图分析涵盖了环境因素,弥补了传统价值流图分析的不足。同时,将环境价值流图分析与仿真技术结合,提高了未来价值流图绘制的客观性。以某电机厂定、转子的生产过程为例,应用环境价值流图从时间和能量消耗2个方面,识别了该厂生产过程存在的问题,以时间及能耗增值率为改善主线,利用工业工程手法与Flexsim仿真等方法进行改善,减少了在制品数,提高了该厂生产过程中的时间增值率。同时,改善了生产过程中的能耗增值率,降低了生产过程对环境的影响。     

生产现场系统化改善的应用性研究

论述了进行生产现场系统化改善的过程。首先根据特定的符号,以可视化的方式描述生产系统的现状,然后设计未来的改进方案、寻找关键技术,最终实施改进方案。在整个过程中,通过物流和信息流的集成分析,区分了生产中的增值和非增值时间,明确了物流中断点,便于暴露生产中存在的浪费;寻找消除这些浪费环节的方法,可以帮助人们更准确地拟定未来的改善方案。最后通过实例证明了生产现场系统化改善所能带来的显著效益。     

制造流程分层次规划方法的研究与应用

结合汽车齿轮制造企业在生产过程中物流的"均衡性"问题,研究了产品制造流程分层次规划方法.提出了将制造流程分析过程系统划分为生产系统层、生产线层、制造单元层进行分析的观点,系统研究了该类方法的理论体系框架及其与优化方法、计算机仿真方法、工业工程方法3类方法集成的实现过程,结合企业的制造过程分析了改善的应用效果.     

From value stream mapping toward a lean/sigma continuous improvement process: an industrial case study

Though lean manufacturing has been widely recognised for its effectiveness in continuously improving productivity, product quality, and on-time delivery to customers, the cost for hiring a full-time lean manufacturing engineer has kept many small businesses from implementing lean in their facilities. This paper presents a case study of lean implementation at a small manufacturer in the United States. Starting with collecting process information, a current value-stream map was created that reflected the current operation status. A future value stream map was then proposed to serve as a guide for future lean activities. Next, hurdles that kept the company from moving towards future state were identified. The ‘5 whys’ method was employed to reveal the root cause for each hurdle, followed by kaizen events proposed as solutions. In this case study, two kaizen events were proposed. For the first kaizen event, Taguchi experiment design was used to find the optimal machining parameters that reduced variation in a plasma cutting process. It consequently eliminated rework time and improved productivity. In the second kaizen event, implementation of rabbit chasing increased the system flexibility and consequently reduced inventory levels between work stations.     

A study on construction of a kaizen case-base and its utilisation: a case of visual management in fabrication and assembly shop-floors

In this paper, focusing on visual management (VM) as one of the kaizen technologies, a procedure for its new case development is discussed. This procedure consists of two portions. The first portion is construction of kaizen case-base, namely: (1) correction and analysis of kaizen cases; (2) establishment of drivers and instances of investigated kaizen case; and (3) analysis of proximity relationship among kaizen cases. The second portion is utilisation of kaizen case-base, namely: (4) selection of kaizen case from kaizen case-base; (5) consideration of the other related kaizen cases; and (6) new kaizen case design. A case study is performed to assure the relevance of the proposed procedure by focusing on ‘dispatching board’, a typical VM technology. Through collaboration with a factory eager to implement VM, the proposed procedure is qualified by experts as a useful method for kaizen knowledge transfer.     

Kaizen costing for lean manufacturing: a case study

In the past decade due to increasing global competition US firms have radically changed their manufacturing practices to improve their competitiveness. In pursuing this goal they have adopted a number of advanced techniques, such as just-in-time, total quality management, lean manufacturing, flexible manufacturing systems, process improvement, and design for manufacturability, to name a few. The objectives of all these programmes have been to reduce cost, improve quality, reduce cycle time, and increase flexibility on the factory floor. Support systems such as finance and cost management, however, have generally not kept pace with the level of corresponding operational changes being implemented. This paper presents a case study of kaizen costing as practised by Boeing Commercial Airplane Company, IRC Division. The purpose of this study is to describe a method used to set kaizen costs which will provide relevant cost data to support lean production decisions that would be useful to practitioners.     

Complexity reduction and kaizen events to balance manual assembly lines: an application in the field

Notwithstanding the existence of a broad research base on assembly line balancing (ALB), companies do not use the mathematical approaches developed in the literature to configure assembly lines. This article aims to fill the gap between research and application by presenting and testing in a real industrial context a methodology based on complexity reduction and kaizen events. First, the methodology supports reducing the complexity that affects real-life assembly systems in terms of the variety of, e.g. finished products, materials and parts. Next, the methodology proposes the conduction of kaizen events by using lean manufacturing tools, such as process analysis, time observation, waste identification, workstation standard documents and yamazumi charts. The methodology is successfully applied to a case study that describes its use in the confectionery process for a major chocolatier company along with the results of the application. The main contribution of this paper consists in presenting a method to manage the line balancing activity within everyday industrial realities, helping practitioners to improve and maintain the performance over time.     

氧化淀粉的制备工艺研究

对氧化淀粉的干法、半干法、湿法3种制备工艺进行了探讨。论述了各工艺的优缺点:干法工艺流程较短、单位产品能耗较低、生产设备较简便,但产品质量不太稳定;半干法工艺虽然增加了一定的生产用水量,但未大量增加工艺流程,且产品质量较高;湿法工艺反应均匀、产品质量较稳定、生产过程较易控制,但存在产品较难回收、生产用水量大,且生产过程中会产生大量污水,给生态环境带来较大压力等缺点。因此,应根据各工艺的缺陷优化氧化淀粉生产工艺,以获得最佳的生产工艺条件。     

The relationship between continuous improvement and rapid improvement sustainability

While rapid improvement efforts, e.g. Kaizen events, and continuous improvement efforts, i.e. kaizen, remain popular approaches to operational excellence, it is rare that organisations fully sustain change from these initiatives. The impact of both Kaizen events and kaizen may be substantially lower, if not entirely eliminated, after significant time has elapsed from initial implementation of changes. In this paper, we examine how having a continuous improvement culture can support rapid improvement sustainability via an examination of the impact of Kaizen events several months after implementation. Employing a dynamic capabilities perspective and using the institutionalisation of planned change framework, we empirically examine this relationship via a field study of 65 Kaizen events in eight manufacturing organisations. In short, we find that the extent to which work area employees exhibit peer learning, as well as awareness and responsibility both inside and outside of their work area, and the extent to which changes are accepted are significantly related to the perceived impact of Kaizen events several months after implementation. This research adds to current understanding of Kaizen events and kaizen, providing evidence to guide the use of Kaizen events and to inform areas for future research.     

Process plan selection based on product mix and production volume

Most shops currently maintain a single process plan for each part type manufactured by the shop even when multiple process plans are feasible to produce the part. The use of a static process plan for a part regardless of the product mix and volume robs the shop of production flexibility and efficiency. In this paper, given that multiple process plans for a part exist, a method to determine the best process plan to implement for a part type in a given production scenario defined by a known product mix and volume is addressed. The method selects a set of process plans to implement based on minimizing total material handling and machining time for the part mix and volume. The problem is modelled mathematically and solved using a heuristic algorithm. Experimental results to describe the performance of the algorithm are presented for different production scenarios, problem sizes, and solution strategies.     

汽车离合器IPPD方法研究

汽车离合器是汽车传动系统的重要起步元件。其传统的设计方法没有在整个产品开发过程中将性能要求、产品特性、工艺过程及过程能力有机地融合,没有考虑离合器产品参数合理的公差范围以及生命周期内尺寸的变化,因此很难满足大规模生产的离合器转矩传递能力和踏板操纵特性的要求。通过建立基于功能—产品特性—工艺及过程能力的汽车离合器IPPD （integrated product and process design,集成产品工艺设计）方法,分析离合器产品特性及工艺参数公差对转矩传递能力和踏板操纵特性的影响,提出了建立精确的传动系统动力学模型的方法,给出了转矩传递能力和踏板操纵特性与产品特性及工艺参数公差的映射关系;在满足可制造性和可装配性的设计要求下,建立了产品特性与工艺过程及参数变化的循环映射关系,采用基于过程能力的稳健公差设计方法进行工艺方案和工艺参数优化。采用所提出的离合器IPPD方法可以更好地使产品满足性能要求,从而为提高离合器设计精度和可靠性提供支撑,为开展离合器的智能设计建立基础。     

基于情感与可供性结构矩阵的产品创新设计研究

目的 旨在弥补可供性结构矩阵在情感内容方面上的不足,进一步明确可供性结构矩阵在产品创新设计中的使用过程。方法 用更为客观的熵权法代替可供性结构矩阵原有的赋权方式,从而实现情感因素的引入,同时结合鱼骨图和冲突矩阵进行问题的分析求解,并以扫地机器人的产品创新进行方法论证。结果 把已有的可供性结构矩阵工具作为一个主导工具,提出了将情感-熵值法将情感因素融入可供性结构矩阵中,形成了完整的产品创新设计流程。结论 对扫地机器人的改进设计证明了该方法的实用性和有效性,丰富完善了可供性结构矩阵方法体系,对之后的产品设计实践提供了参考。     

A decomposition method for multi-product kanban systems with setup times and lost sales

We consider kanban controlled production systems with three or more different products processed on a single manufacturing facility. Customers for a product arrive according to a Poisson process. If a customer's demand cannot be met from stock, the customer leaves and satisfies his demand elsewhere (lost sales). Between the production of different products setup changes must be performed that take a significant time. Setup times and processing times are product-specific and follow exponential distributions. A production run continues until the target inventory level given by the number of kanbans for the product has been reached (exhaustive processing). Then the manufacturing facility is set up for the next product according to a fixed setup cycle. The exact model is mathematically intractable even for smaller systems. Therefore, we propose a decomposition-based approximation method for estimating steady-state performance measures