Scheduling problems — An overview

There seems to be a significant gap between the theoretical and the practical aspects ofscheduling problems in the job shop environment. Theoretically, scheduling systems are designed onthe basis of an optimum approach to the scheduling model. However in the practice, the optimum thatis built into the scheduling applications seems to face some challenges when dealing with the dynamiccharacter of a scheduling system, for instance machine breakdown or change of orders. Schedulingsystems have become quite complex in the past few years. Competitive business environments andshorter product life cycles are the imminent challenges being faced by many companies these days.These challenges push companies to anticipate a demand driven supply chain in their businessenvironment. A demand-driven supply chain incorporates the customer view into the supply chainprocesses. As a consequence of this, scheduling as a core process of the demand-driven supply chainmust also reflect the customer view. In addition, other approaches to solving scheduling problems, forinstance approaches based on human factors, prefer the scheduling system to be more flexible in bothdesign and implementation. After discussion of these factors, the authors propose the integration of adifferent set of criteria for the development of“ scheduling systems which not only appears to have abetter flexibility but also increased customer-focus.     

基于动态生产能力约束的MC模式下供应链调度优化

大规模定制(MC)模式下的供应链调度优化过程是典型的随机需求与资源约束的动态问题。为合理解决这一问题，在前期研究成果基础上，着重从供应链系统中各协作成员的动态空余生产能力角度出发，指出动态空余生产能力约束关系是该调度优化过程的主要约束关系。进而分析了由该约束关系引发的相关矛盾。通过引入反映和解决矛盾的利益偏好因子，建立了更加完善的动态调度优化数学模型，并通过实例验证了模型的有效性与可行性。     

Feasibility-Oriented Application of System Analysis in SMEs-The Cybernetic Approach of VSM Applied to Horticultural Retail Companies in Germany

Many approaches of business analysis focus on single disciplines or specific problems but ignore complex and dynamic interrelations between small and medium-sized enterprises (SMEs), their stakeholders, and their business environment. In order to meet these challenges, the system analysis tool Vester sensitivity model (VSM) is applied on a reference company representative of the German horticultural retail sector. Based on the principles of system theory and (bio-) cybernetics, the VSM system building tool uses net thinking, heuristics, and a participatory approach to illustrate and evaluate the systemic role of relevant key variables, and their interrelations in the example company. In this article, the analytical steps of the VSM are applied up to the finalized effect system model of the reference company. As an innovative aspect, the article emphasizes how the multilevel process of the system analysis can be put into practice more effectively by using interactive media tools to enable the required communication and consensus by the participating stakeholder panel. Elements such as the manager’s ability of strategic planning, the organizational climate, and the company’s image were uncovered as critical, but also stabilizing key factors for such companies. Although the study focuses on the specific situation of German horticultural retail companies as the research subject, the suggested procedure of integrated knowledge generation is transferrable to any business, industry branch, and country. Especially scholars, advisors, and business analysts working in the field of SME management can use the concept to evaluate such systems in the overall context of the companies under investigation.     

知识经济时代的过程系统工程——面临的挑战与发展的趋势

对过程系统工程这门学科面向 2 1世纪所面临的挑战及发展方向做了综合性评述 .首先对新世纪过程工程系统发展的特点及其对系统工程的需求进行了综合介绍 .在此基础上 ,从五个方面论述了本学科的发展方向 :1 )研究对象“过程系统”从传统的中观点系统向两头延伸 :一方向的产品设计为代表的微观世纪延伸 ;一方面向以供应链管理及全球环境化学为代表的超大规模系统延伸 ;2 )“过程”涵义自制造过程延伸到经营管理业务决策过程 ;3 )考虑环境影响的绿色过程系统工程 ;4)动态过程系统工程 ;5 )过程集成 .     

关于同速机类型供应商任务交付顺序的协调

供应链各成员的协同调度能够显著提高供应链整体生产效率. 以装配系统为背景，研究机器类型为同速机和单机的零件供应商关于多任务交付顺序的协调. 在无主导方的情况下，建立了基于纳什谈判理论的协调机制，并针对一类含乘积式目标函数的调度问题，设计了基于序列临位交换（API）的多项式时间启发式算法. 通过数值算例，确认了该机制在协同调度中所发挥的作用.     

面向重要供应商和客户的供应链设计方法

与重要供应商和高价值客户建立良好的关系，已经成为企业获得竞争优势的必然选择。本文从供应链核心企业的角度出发，提出了一种面向重要供应商和客户的供应链设计方法。该方法将供应链设计分成两个阶段。首先，利用模糊综合评判法对核心企业的供应商和客户进行评价，获得它们的重要度。然后，建立一个多目标混合整数规划模型来描述供应链设计问题。与基于成本最小化或利润最大化的传统供应链设计模型相比，该模型体现了关系管理的思想，考虑（1）优先向具有较高重要度的供应商采购原料，以建立长期稳定的合作关系。（2）分销中心的选址要尽量接近重要的客户或客户区，以缩短订货的提前期，提高客户服务水平。     

FROM MANUFACTURING SCHEDULING TO SUPPLY CHAIN COORDINATION：THE CONTROL OF COMPLEXITY AND UNCERTAINTY

With time-based competition and rapid technology advancements, effective manufacturingscheduling and supply chain coordination are critical to quickly respond to changing marketconditions. These problems, however, are difficult in view of inherent complexity and variousuncertainties involved. Based on a series of results by the authors, decomposition and coordination byusing Lagrangian relaxation is identified in this paper as an effective way to control complexity anduncertainty.A manufacturing scheduling problem is first formulated within the job shop context withuncertain order arrivals, processing times, due dates, and part priorities as a separable optimizationproblem. A solution methodology that combines Lagrangian relaxation, stochastic dynamicprogramming, and heuristics is developed. Method improvements to effectively solve large problemsare also highlighted. To extend manufacturing scheduling within a factory to coordinate autonomicmembers across chains of suppliers, a decentralized supply chai     

A production optimization model of supply-driven chain with quality uncertainty

Supply-driven chain’s production is different from traditional demand-driven production because its supplies must guide the full production flow toward the markets and respond actively to customer demand. According to the control theory, a novel multi-variable operation model of supply-driven chain is discussed here, integrating suppliers, manufacturers, distributors and market demands. Especially the coordination problem between suppliers and manufacturers is discussed where suppliers play more important role than manufacturers. Because defect is common in real production system, the production operation of supply-driven chain with imperfect quality is described on the basis of fuzzy set to model the ambiguity of quality and to provide appropriate supply coordination mechanism. In a designed numerical example, it is apparent that both response and robustness performances of supply-driven production system on demand with imperfect quality are improved by a fuzzy proportional-integral- differential regulator. The proposed model may apply to similar productions with imperfect quality.     

LOGISTICS SCHEDULING： ANALYSIS OFTWO-STAGE PROBLEMS

This paper studies the coordination effects between stages for scheduling problems where decision-making is a two-stage process. Two stages are considered as one system. The system can be a supply chain that links two stages, one stage representing a manufacturer; and the other, a distributor It also can represent a single manufacturer, while each stage represents a different department responsible for a part of operations. A problem that jointly considers both stages in order to achieve ideal overall system performance is defined as a system problem. In practice, at times, it might not be feasible for the two stages to make coordinated decisions due to (i) the lack of channels that allow decision makers at the two stages to cooperate, and/or (ii) the optimal solution to the system problem is too difficult (or costly) to achieve.Two practical approaches are applied to solve a variant of two-stage logistic scheduling problems. The Forward Approach is defined as a solution procedure by which the first sta     

增量模型控制压力恒定的多源供水实时调度

针对多水源供水管网系统参数多及变量间存在耦合,难以实现合理实时调度而导致水压多变等问题,提出一种基于增量模型控制压力恒定的多源供水管网系统优化调度策略. 依据用户流量参数预测建立增量模型,以分界监控点压力参数恒定为目标函数推导多水源调度策略,并调节机泵输出压力,机泵启停状态及变频机泵转速为优化决策变量. 鉴于供水系统模型的非线性和混合变量的耦合性,采用蚁群算法进行优化,引进扰动因子并修正搜索转移步长和动态挥发系数来提高全局寻优能力. 算例仿真表明,该模型和方法可快速找到优化调度的最优解,跟踪流量变化和保持监测控制节点实时压力恒定的效果好,为多水源的实时协调调度提供了好的基础.     

A Nonprecedence－based Query Schedule Algorithm on Heterogeneous Multiprocessor System

ＡＮｏｎｐｒｅｃｅｄｅｎｃｅ－ｂａｓｅｄＱｕｅｒｙＳｃｈｅｄｕｌｅＡｌｇｏｒｉｔｈｍｏｎＨｅｔｅｒｏｇｅｎｅｏｕｓＭｕｌｔｉｐｒｏｃｅｓｓｏｒＳｙｓｔｅｍ￥ＨｅＪｕｎ；ｂａｎｇＤｉｎｇｘｉｎｇ＆ＺｈｅｎｇＷｅｉｍｉｎ（ＤｅｐａｒｔｍｅｎｔｏｆＣｏｍｐ...     

考虑中断的制造型供应链协调调度模型

供应链协调调度能有效提高企业应对供应链中断的能力。以两阶段制造供应链为研究对象，研究了中断情境下具有交付时间约束的多产品类型制造供应链协调调度问题。制造商接到包含多产品类型的工件加工订单，各工件需经供应商处理为原材料工件后，交付给制造商处理为完成品，各工件均有一个独立的交付期。如果供应商单方面调整工件加工顺序，会导致制造商冲突成本的增加，需双方协商处理。以最小化供应商总拖期交付成本和最小化制造商总冲突成本为目标，基于收益共享契约协调机制，构建了考虑中断的制造型供应链协调调度模型。设计了一个融合自适应邻域搜索算子的混合自适应遗传算法。通过算例仿真，验证了所提模型与算法的有效性。     

复杂印记与调度回响

利用雷舍尔的复杂性模型,从组分复杂性、结构复杂性和功能复杂性等本体论复杂性方面,以及描述复杂性、生成复杂性和计算复杂性等认识论复杂性方面分析了生产调度问题的复杂性.指出实际生产中的调度问题,应作为复杂系统进行研究.针对调度的本体论复杂性,阐明了复杂系统观的重要性;结合认识论复杂性,对复杂系统观下的复杂性消减进行了说明,...     

网格环境下复杂过程系统优化计算服务及任务调度策略

针对目前优化计算服务缺乏对一般用户的优化计算支持和灵活的资源共享方式,提出利用网格环境、支持网络计算资源以并行的、协同的方式提供面向服务的优化功能的计算服务系统,并设计了对系统性能具有重要影响的动态任务调度算法,从而使系统能够适应复杂过程系统优化计算以及网格环境的典型特征.相应地,系统采用多任务队列的任务管理方式和计算节点组的资源管理方式,为该调度策略提供实现基础.测试结果体现了基于该调度算法的优化计算服务系统的良好性能,并为设计在该系统下高效运行的并行算法提供了参考依据.     

MC模式下供应链调度的优化模型

MC模式研究的关键问题是如何处理规模生产效应同客户个性化定制需求之间的关系。当MC在供应链环境下运作时，供应链体系优良的运作特征为该问题的解决创造了条件。在前期研究成果所提出的MC模式下供应链调度过程中主导矛盾及其解决途径基础上，通过将其引入调度的运作过程，建立了MC模式下供应链调度的动态、多目标优化数学模型。深入分析了模型的显性及隐性意义，指出模型的特点不仅能够反映该生产方式独特的运作特征要求，而且融入了对主导矛盾的解决思路。通过实践检验，说明模型在提升MC模式下供应链调度效率以及解决上述关键问题中均具有可行性。     

赛汝生产系统构建与调度的研究进展

作为一种新的生产模式,赛汝生产(SERU production)因其响应快、柔性高、效率高的优势在佳能、索尼等电子产品制造企业被广泛采用并取得很好的效果,也因此引起了学术界的广泛关注.赛汝生产系统运作至少包括赛汝生产系统构建和调度两个关键决策过程,而且这两个决策过程都是NP难问题.为了降低计算复杂度,大多数已有研究都是对赛汝生产系统构建和调度进行单独决策,但赛汝生产系统构建和调度的单独决策无法产生全局最优解.为获得全局最优解,需要联合决策赛汝生产系统构建和调度.本文从赛汝生产系统构建与调度的单独决策、纯赛汝生产系统构建与调度的联合决策、混合赛汝生产系统构建与调度的联合决策三个方面,介绍和总结了赛汝生产系统构建和调度的研究进展,展望了未来的相关研究方向.     

面向能耗的云工作流调度优化

云工作流调度直接决定了整个云工作流系统的性能,已成为一个重要研究内容.针对当前缺乏有效的面向能耗的云工作流调度优化方法,研究建立了面向能耗的云工作流过程模型、资源模型,提出了基于负载的能耗计算方法和面向能耗的云工作流调度优化算法.提出的方法考虑了能耗因素,在进行任务优先级计算及任务选择时不仅考虑了文件在不同虚拟机间传输的速度差异、同时考虑了虚拟机与本地共享数据库间的文件传输等因素,并从云工作流任务分配、主机负载和主机功耗关系的角度,进行能耗的计算与调度优化,更符合实际情况、使用范围更广.数值案例和仿真实验表明了提出的方法是可行的和有效的.     

基于网格的商品流通领域供应链信息集成效率

将网格技术应用于供应链信息集成中是适应竞争环境变化的必然要求。以商品流通领域供应链信息集成为例,首先简要介绍了商品流通领域供应链信息集成,然后利用时间Petri网对传统模式下企业供应链和网格环境下供应链集成系统的信息共享和业务运作模式的效率进行了对比分析。分析结果验证了网格环境下供应链集成系统效率的优越性。     

基于供应商满意度与模糊能力的服务大规模定制供应链调度优化

稳定多样的服务资源是服务大规模定制绩效的重要保障，服务集成商不单要重视客户需求，还要注重提高供应商满意度，从而吸引更多服务资源整合到服务供应链中。供应商满意度被分解为订单需求偏好和协调配合程度两个维度，并从服务供应链的集成特性和供应商相互制约特性出发，论述了其对服务大规模定制模式下供应链调度方案的重要影响。服务供应商的需求偏好与动态联盟造成供应商服务能力的不确定性。构建基于供应商满意度与模糊能力的多目标、多阶段供应链调度优化模型和求解算法。模型较好地模拟了服务定制订单的复杂性与服务能力的不确定性，算例分析验证了模型与算法的有效性。     

一种基于自适应控制的软实时调度算法研究

控制理论应用于软实时系统的调度问题，仅采用经典反馈控制技术存在较大的局限性。针对CPU资源实时调度模型的时变特点，提出一种基于自适应反馈控制结构的软实时调度算法，通过在线实时辨识模型的时变参数，自动校正控制器参数，使控制系统运行在期望的闭环极点，改善了实时系统的动态响应特性，同时对系统模型的参数时变具有较好的鲁棒性，提高了实时系统的稳定性和资源的利用率。