JIT供应物流的短驳合并运输集成优化研究

针对及时化(just in time,JIT)供应模式的入场物流短驳合并优化问题,本文以某汽车制造厂的入厂物流为例,并以供应物流总成本最小为目标,建立数学模型,同时利用基于递降最佳适合算法(best fit decreasing,BFD)思想的启发式算法和改进的单亲遗传算法(partheno genetic algorithm,PGA)求解,并分析在此运作模式下的成本与效率。仿真结果表明,单亲遗传算法取消了传统遗传算法的交叉算子,取而代之仅在一条染色体上操作基因换位算子,即使种群中每个个体均相同,它也可以通过基因换位、基因到位等遗传算子来实现遗传迭代,不需要初始群体具有广泛多样性,也就不存在早熟收敛的现象。因此,本文提出的算法比BFD启发式算法的供应成本明显降低。该研究可降低供应成本,提高经济效益。     

A note on ‘A bit-wise mutation algorithm for mixed-model sequencing in JIT production systems’ (Nazar & Pillai, 2015, IJPR, 53:19, 5931-5947)

This note discusses three points about the problem of sequencing units on a mixed-model assembly line in ‘A bit-wise mutation algorithm for mixed-model sequencing in JIT production systems’ (Nazar & Pillai, 2015, IJPR, 53:19, 5931-5947). Specifically, the mixed-integer quadratic model, the bit-wise mutation algorithm and the bi-objective problem to optimise both product rate variation and makespan. The conclusion of the discussion is that the three alleged contributions are not valid or are outperformed by those presented in some previously published papers.     

A systematic review/survey for JIT implementation: Mexican maquiladoras as case study

Mexico has a free trade agreement with the United States of America (USA) and Canada which was signed in 1988. This agreement created the conditions for establishing many foreign companies in several Mexican cities along the border zone between Mexico and USA. This strategy takes advantage of the geographic proximity with one of the biggest markets in the world, qualified manpower, and low production cost. With the arrival of those companies, frequently called Maquiladoras, a lot of production approaches have been introduced, and one of those widely applied is the just-in-time (JIT) production strategy. Despite the benefits of JIT, the interrelationship among several industrial factors and their impact on results derived from the implementation of JIT are unknown in Mexico. This is the underlying reason of this article, which aims at illustrating the results of a survey applied to foreign companies established in the Mexican–USA border. On the one hand, the activities developed by these companies during the implementation process of JIT are investigated and grouped as latent independent variables. These variables include organizational commitment, communication channels in organization, empowerment granted to employees, education provided in different organizational levels, and the capacity to solve problems, among others. On the other hand, the obtained benefits investigated are grouped as latent dependent variables. These dependent variables involve inventory management, quality, and cost, among others. Those aspects in the activities and benefits of the companies were evaluated using the structural equations model (SEM), which is useful to identify and analyze causal relationships. Result obtained from SEM indicates that management commitment and education are the main critical success factors in the JIT implementation, and that success can be measured through inventory, quality, and cost performance indicators.     

基于JIT的供应链合作批量研究

研究了JIT生产模式下的供应链合作问题,分析了两种不同的优化机制,比较了独立优化与合作优化下的最优批量政策和相应的成本,结果表明了供需双方进行合作博弈,共享合作收益是最佳策略.     

MRPII、JIT、TOC生产计划与控制比较研究

在对MRPII、JIT、TOC三种生产管理思想的适用性和优缺点分析、比较的基础上,在生产计 划与控制的不同层面,根据不同要求,对MRPII、JIT、TOC 进行了定位分析,并把MRPII定 位在厂级或企业级,负责主生产计划、物料需求及各车间零部件的月、周计划;TOC定位在车 间级,负责车间或工段工序日作业计划与调度、物料的投放;JIT定位在生产现场,负责作业 计划的执行、生产的控制和现场的反馈。     

JIT生产系统Petri Net建模与仿真研究

激烈的全球市场竞争要求企业对动态需求具有较强的反应能力，同时对自身生产系统的随机特性有较强的把握和控制。制造企业倾向于采用JIT看板生产理念来改善企业的QCD。这里首先建立JIT看板生产系统基本流程的Petri Net模型，然后运用WITNESS建立了一个单产品、多阶段、混联的JIT生产系统仿真模型，通过仿真实验，研究和分析了需求和生产两方面的随机变量在不同的组合下，其变异系数对系统绩效指标的影响。     

Just‐in‐time management in the ready mixed concrete industries of Chongqing,China and Singapore

Implementing just‐in‐time (JIT) management in the ready mixed concrete (RMC) industry seems viable. It has been observed previously by others that the current practices for managing the concrete supply chain upstream in terms of raw materials acquisition or prerequisite work on site were not geared toward JIT production. However, it is unclear if this observation is also relevant for the procurement of raw materials in the RMC industry in Chongqing (in China) and Singapore. Hence, the purpose of this study is to investigate the implementation status of JIT in the RMC industry in Chongqing and Singapore. The field study conducted found that all the RMC suppliers surveyed were using the demand pull system to manage RMC production and delivery to sites. However, the study also found that the raw materials could be purchased either using the JIT purchasing method or the traditional economic order quantity (EOQ) purchasing method. Further studies to investigate the conditions where a RMC supplier can adopt the JIT purchasing method to procure its raw materials are recommended.     

面向供应链的生产组织计划模式研究

针对大型制造企业的运营形式，提出了一种基于MRPII推式／JIT拉式结合的面向供应链的生产组织计划模式，并探讨了基于该模型的生产计划系统的具体实施策略。     

丰田JIT系统中人本理念的探究

指出了既有丰田JIT系统存在的弊端,介绍了人本理念的由来.总结了JIT系统中对人的尊重在于对设备及生产管理过程的持续改进.在丰田制造工艺过程改善上,陈述了设备投资的着眼点在于:为操作人员所用、改善工作环境、减轻劳动强度,并给出了相关的具体实例.     

关于KVM中预处理程序的研究

提出了扩展属性以扩充预处理模块功能的思想 ,给出了扩展属性的方法及属性格式 ,简述了KVM中使用这些属性的基本方法。