以JIT为目标的多阶段非等同并行机调度问题研究

针对多阶段非等同并行机模式下的准时化(Just-in-TimeJ,IT)调度问题,采用由遗传算法和禁忌搜索算法混合的禁忌遗传递阶算法进行求解。禁忌遗传递阶算法用禁忌搜索算法对工件最佳加工次序进行搜索,而相应评价值由遗传算法计算得出。遗传算法采用基于阶段机器号的二维矩阵编码,可有效地避免不可行解的产生,同时采用自适应改进提高遗传算法跳出局部最优的能力。实际算例说明禁忌遗传递阶算法计算结果稳定可靠,适合于解决多阶段非等同并行机的JIT调度问题。     

JIT在工程管理中的应用

结合我国建筑企业施工管理背景,针对施工管理过程中库存、人员素质及管理方式等方面存在的问题进行了分析,提出以JIT思想为主导的管理方法并作了具体阐述,以期促进国内工程项目管理水平的提高。     

现代企业生产管理技术之一——JIT技术

介绍JIT(Just in time-准时化生产技术)的概念、JIT的基本原理、7种浪费类型。在此基础着重论述在JIT应用中的3个原则、8个管理项目以及如何构建JIT制造单元。JIT生产不仅仅是一种生产技术,更重要的是它是一种全新的管理模式,它不但能消除明显的浪费,而且能消除隐藏的浪费。     

Packaging and world class competitive products

The aim of the Irish food industry is to produce world class competitive products (WCCPs). Stating the obvious: Food and packaging are inseparable and thus WCCP status is a target also for packaging manufacturers in their own right and also as to how packaging assists food companies to achieve their aims.     

基于即时学习算法的短期负荷预测方法

针对电力系统短期负荷数据存在非线性和时变性等问题,提出了一种变量相关性局部即时学习算法和最小二乘支持向量机(LSSVM)的电力系统短期负荷预测模型。利用互信息计算气象数据、各气象因素等变量的相关度,并引入到即时学习算法训练集中,用以选择当前电力系统负荷的建模邻域,提高系统短期负荷模型预测的精度。利用相似度阈值对局部模型进行自适应更新,增强系统负荷模型实时性。利用Matlab对某市宛城区的负荷量进行预测,结果表明,基于即时学习算法的电力系统短期负荷预测模型误差更小,系统预测精度更高。     

Comparing TOC with MRP and JIT: a literature review

Since the early 1980s, manufacturing philosophies such as manufacturing resource planning (MRP), just-in-time (JIT), and theory of constraints (TOC) have emerged as distinct, viable, and competitive planning and control systems for improving the organisational performance. Comparative literature outlines many similarities and differences among these philosophies and attempts to answer the question: what is the best choice? With this question in mind, this paper reviewed the journal articles comparing TOC with MRP and JIT and provided specific future research directions. Although TOC is shown to compete effectively against MRP and JIT and thereby, holds promise, the results are still inconclusive primarily because the majority of journal articles lack in one respect or the other in terms of realistic examples modelled, breadth of characteristics considered, rigorous methodology employed, and depth of statistical analysis performed. In terms of future research directions, we develop a comprehensive list of characteristics by drawing on the literature reviewed and suggest some specific empirical as well as analytical research streams.     

An integrated optimal inventory lot-sizing and vehicle-routing model for a multisupplier single-assembler system with JIT delivery

In a manufacturing system, a just-in-time (JIT) procurement and supply system is important for reducing cost and responding to customer’s requirement quickly. Successful implementation of a JIT system needs supplier/manufacturer cooperation in small lot-size delivery and inbound logistics cost reduction. In this study, an integrated optimal model of inventory lot-sizing vehicle routing of multisupplier single-manufacturer with milk-run JIT delivery is established. A novel method for computing transportation cost is proposed. Because the integrated model is a NP-hard problem, a meta-heuristic algorithm of ant colony optimisation is developed for solving the model. Numerical examples are used to demonstrate and test the effectiveness of the model and the algorithm. The results show that integrated model with milk-run delivery can reduce the total cost and realise the JIT production and procurement philosophy which emphasises small lot-size production and delivery. The results highlight the importance of cooperation between suppliers and manufacturers in JIT production practices.     

对用户交互响应进行加速的即时编译技术

对于影响用户交互响应速度的瓶颈代码段,现有即时编译器存在无法准确选取和在程序启动阶段没有可用的本地码进行加速的问题,这影响了即时编译技术在用户交互响应方面的加速效果。为此,对即时编译器原有的代码选择策略和编译模式进行了改进。在代码选择策略方面,应用程序可以根据实际运行情况主动选择要编译的代码段,保证所有影响用户交互响应速度的瓶颈代码段都能被选取并被加速;在编译模式方面,本次编译得到的本地码可以保存并供程序下次运行时使用,保证在程序启动阶段也有本地码可用来加速。应用程序启动速度的实验表明,改进的即时编译器能够提升1倍的用户响应速度。     

基于JIT的无B/C类成品库存方法研究

针对实施JIT的现有库存控制方法进行了探讨,认为完全地追求“零库存”不适合我国制造业现状,并从供应链管理的角度引入提出了与JIT相匹配的无B／C类成品库存供应链管理策略方法,指出了应用时的实施要点。     

基于JIT的精益物料管理

精益物料管理是社会发展到信息技术时代的必然产物。介绍了精益思想的核心,阐述了精益物料管理的含义和目的,重点研究了精益物料管理的流程。指出了精益物料管理是我国企业物料管理的发展方向。