A hybrid multi-objective shuffled frog-leaping algorithm for a mixed-model assembly line sequencing problem

In this paper, a mixed-model assembly line (MMAL) sequencing problem is studied. This type of production system is used to manufacture multiple products along a single assembly line while maintaining the least possible inventories. With the growth in customers’ demand diversification, mixed-model assembly lines have gained increasing importance in the field of management. Among the available criteria used to judge a sequence in MMAL, the following three are taken into account: the minimization of total utility work, total production rate variation, and total setup cost. Due to the complexity of the problem, it is very difficult to obtain optimum solution for this kind of problems by means of traditional approaches. Therefore, a hybrid multi-objective algorithm based on shuffled frog-leaping algorithm (SFLA) and bacteria optimization (BO) are deployed. The performance of the proposed hybrid algorithm is then compared with three well-known genetic algorithms, i.e. PS-NC GA, NSGA-II, and SPEA-II. The computational results show that the proposed hybrid algorithm outperforms the existing genetic algorithms, significantly in large-sized problems.     

A hybrid multi-objective shuffled frog-leaping algorithm for a mixed-model assembly line sequencing problem

In this paper, a mixed-model assembly line (MMAL) sequencing problem is studied. This type of production system is used to manufacture multiple products along a single assembly line while maintaining the least possible inventories. With the growth in customers’ demand diversification, mixed-model assembly lines have gained increasing importance in the field of management. Among the available criteria used to judge a sequence in MMAL, the following three are taken into account: the minimization of total utility work, total production rate variation, and total setup cost. Due to the complexity of the problem, it is very difficult to obtain optimum solution for this kind of problems by means of traditional approaches. Therefore, a hybrid multi-objective algorithm based on shuffled frog-leaping algorithm (SFLA) and bacteria optimization (BO) are deployed. The performance of the proposed hybrid algorithm is then compared with three well-known genetic algorithms, i.e. PS-NC GA, NSGA-II, and SPEA-II. The computational results show that the proposed hybrid algorithm outperforms the existing genetic algorithms, significantly in large-sized problems.     

CPS技术在柔性滑板生产线中的运用研究

柔性滑板生产线是一种采用柔性摩擦驱动的汽车装配输送线,可提高装配效率和系统自由度。无接触供电技术(Contactless Power Supply,CPS)是一种安全、灵活、有效的新型供电技术。在柔性滑板生产线中运用CPS技术,可以提升滑板的速度和负载能力,人机协调性良好,实现了高效、柔性的随行装配,提升了物流自动化程度。     

装配生产车间制造执行系统的设计

制造执行系统(MES)是制造企业中面向车间层的管理系统,将企业资源管理系统与车间生产现场设备控制有机联系起来。结合MES系统设计开发实践,对装配生产线配置、物流和数据流程作了深入分析,并就装配生产车间MES系统的体系结构和功能结构等进行介绍。     

基于Agent的可重构装配线制造执行系统

针对制造执行系统存在的问题,根据可重构制造模式的理念,设计基于CORBA和多Agent的可重构装配线制造执行系统的体系结构,实现制造执行系统的可重构性和可集成性,构建系统的IDEF0功能模型,给出Agent结构模型及装配资源聚类方法。实际应用表明该系统具有良好的实用性,能满足企业需求。     

A note on Toyota's goal of sequencing mixed models on an assembly line

Toyota's goal of sequencing mixed models on an assembly line is to keep the constant usage of every part used in the assembly line. This goal is a good way of fitting the just-in-time concept in Toyota’s production system. In all of Toyota's goal oriented studies a consideration which has not been explained explicitly in the literature is that all the parts of a given product are assumed to be used at the epoch of just this unit into the assembly line. This treatment is equivalent to an assumption of a single workstation assembly line with zero length. For an assembly line with multiple workstations, however, it is clear that the parts of a given product are used at different epochs subsequent to originally feeding this unit into it. This note discusses Toyota's goal of sequencing mixed models on an assembly line with multiple workstations. The sequencing problem is formulated based on defining the ideal usage rate of a part as the requirement for the part per time period. A modified goal chasing algorithm is proposed for solving this sequencing problem. An example is given to illustrate the methodology.     

Ergonomic planned supply in an automotive assembly line

The objective of this research is to identify the benefits of ergonomic improvements in workstations and in planned parts supply in an automotive assembly line. Another aim is to verify to what extent it is possible to create competitive advantages in the manufacturing area with reduction in vehicle assembly time by using technological investments in ergonomics with benefits to the worker and to the company. The Methods Time Measurement (MTM) methodology is chosen to measure the process time differences. To ensure a reliable comparison, a company in Brazil that has two different types of assembly line installations in the same plant was observed, and both assembly lines were under the same influences in terms of human resources, wages, food, and educational level of the staff. In this article, the first assembly line is called “new” and was built 6 years ago, with high investments in ergonomic solutions, in the supply system, and in the process. The other is called “traditional” and was built 23 years ago with few investments in the area. © 2010 Wiley Periodicals, Inc.     

电子装配行业的MES体系结构及技术实现

针对电子装配行业的特点和制造执行系统（MES）的需求,采用基于SOA的设计方法和理念,提出基于Web服务的MES软件体系结构,建立基于工作流的电子装配过程实时可视化、实时生产排程、实时生产过程跟踪技术框架。提出基于WebServices技术和J2EE平台的软件体系结构技术实现框架。开发的MES系统应用在某SMT车间,证明该系统具有较好的实时、可配置、可重构、可集成性能。     

MES与PLC实时通信系统研究

使用MES系统是为了更好地实现生产过程中的可视化监控及生产数据管理,如何更好实现MES系统与PLC及现场设备精准实时通信是各个生产型企业争相研究的热点问题.针对以上问题,通过研究西门子S7-300 PLC与GE公司的MES系统,设计在PLC中与MES实时通信的FB块VDCA,自定义上位机与下位机的通信报文,通过Enternet实现上位机与下位机的实时通信.该设计减少了中间硬件,提高了通信过程中的数据稳定性,可操作性与通用性强,适用于工序多样的自动化生产线,实际运用到了发动机装配生产线,提高了发动机装配效率.     

基于智慧车间的生产执行系统的研究及应用

为了解决中小型塑料制造企业管理系统在信息采集方式、计划实时性、灵活性等方面的不足,将射频识别Radio Frequency Identification(RFID)技术引入塑料生产车间,构建塑料制造装配车间的物料智能配送体系,形成面向离散制造业的智慧装配车间。对生产执行系统Manufacturing Execution System(MES)的架构、RFID智慧生产车间应用流程、应用可靠性等关键技术进行了研究,并对车间生产组织、制造事件和动态多变市场的响应能力进行了优化。所述内容对提升塑料制造企业核心竞争力具有重要的理论与实际意义。     

Supply chain modeling in uncertain environment with bi-objective approach

Supply chain is viewed as a large-scale system that consists of production and inventory units, organized in a serial structure. Uncertainty is the main attribute in managing the supply chains. Managing a supply chain (SC) is very difficult, since various sources of uncertainty and complex interrelationships among various entities exist in the SC. Uncertainty may result from customer’s demand variability or unreliability in external suppliers. In this paper we develop an inventory model for an assembly supply chain network (each unit has at most one immediate successor, but any number of immediate predecessors) which fuzzy demand for single product in one hand and fuzzy reliability of external suppliers in other hand affect on determination of inventory policy in SCM. External supplier’s reliability has determined using a fuzzy expert system. Also the performance of supply chain is assessed by two criteria including total cost and fill rate. To solve this bi-criteria model, hybridization of multi-objective particle swarm optimization and simulation optimization is considered. Results indicate the efficiency of proposed approach in performance measurement.     

基于本体融合的动态供应链信息平台研究与实践

结合EDI标准,应用领域本体融合技术,对供应链管理系统中的数据异构问题给出了一种解决方案.为解决融合过程中本体规模过大的问题,引入了基于业务侧面的领域本体BAO(Business Aspect Ontology)概念,从业务流程入手抽象领域本体到不同BAO.此外还具体分析了BAO在供应链执行SCE(Supply Chain Execution)与供应链规划SCP(Supply Chain Planning)中的应用.     

从复杂性的角度分析供应链管理问题

供应链是企业适应市场环境变化而产生的运作模式,也是企业之间竞争与协同发展的产物。供应链是由多个企业组成的复杂供需网络,因此它属于开放的复杂巨系统的范畴,而处理开放的复杂巨系统的有效方法是综合集成研讨体系。该文首先介绍了复杂性的研究情况;分析了供应链的复杂性;指出供应链是一个开放的复杂巨系统;提出用综合集成研讨厅体系的思想研究供应链管理问题,为供应链管理问题的研究提供了一个新的思路。     

Modeling enablers of supply chain risk mitigation in electronic supply chains: A Grey–DEMATEL approach

Supply chains are becoming perpetually complex and potentially vulnerable due to increased globalization and vertical integration. Supply chain managers are conscious that the success of any supply chain lies in its proficiency to manage risks efficiently and effectively. Supply chain risk management (SCRM) signifies proactive practices of managing vulnerability of supply chains. Various firms espouse strategic level measures for risk mitigation and implement practices for enhancing supply chain resilience. In order to enhance supply chain resilience, the enablers of supply chain risk mitigation need to be acknowledged and implemented into practice. This research emphasizes on ascertaining the major enablers of supply chain risk mitigation with emblematic focus on electronic supply chains. A blend of Grey theory and DEMATEL approaches has been employed in this research to find out cause/effect relationships among the enablers of supply chain risk mitigation. This exercise helps to find which can be the driver to initiate the effects of other driven enablers. Sensitivity analysis was also conducted of the results to ensure reliability of solutions. The results show that that the enablers of supply chain risk mitigation are intertwined and one enabler can be the cause/effect of one or more enablers of supply chain risk mitigation. Dynamic assortment planning is found to be the decisive causal enabler, as it initiates the effects of many other enablers of supply chain risk mitigation, followed by accurate demand forecasting and flexible supply contracts. Cause–effect relationships plotted facilitate managers to ascertain primary causal enablers that need imperative attention in dealing with vulnerability issues of supply chain. Managers can take proactive steps to address and implement primary causal enables of risk mitigation into practice for reducing total risk impacts of the supply chain.     

统一集论在病体供应链建模中的应用

供应链系统是一复杂巨系统,它的结构和运作模式决定了其复杂性。文章从认知思维基础出发来认识供应链系统的复杂性并将智能数学的最新成果——统一集及其分支运用于供应链系统的建模。     

Reconfiguration of assembly systems: From conveyor assembly line to serus

Confronted with the dynamic and complex market environments, the traditional conveyor assembly line can no longer meet customers’ demands effectively. The way of reconfiguring conveyor assembly line to a more flexible manufacturing system has been attracting considerable attention both in the academics and production practices. Seru system, also called assembly cell system, is regarded as one of the most successful innovations of manufacturing system in reconfiguring conveyor assembly line. Such a manufacturing system merges considerable flexibility of job shops and high efficiency of conveyor assembly lines to some extent. In this paper, we investigate the problem of how to reconfigure conveyor assembly line to serus. A comprehensive mathematical model incorporating two issues of how many serus should be established and how many workers should be assigned to each seru is developed. Then the model is investigated by an industrial case and compared to Kaku's model with respect to the selected plan. The computation results validate that the proposed model is more suitable to analyze the reconfiguration problems from conveyor assembly line to serus.     

基于工作流的电装行业MES关键技术研究

电子装配行业的特点要求电子装配行业MES系统实现实时可视化、动态生产排程、装配过程跟踪等功能,同时实现系统可配置、可重构、实时、可集成等.采用工作流技术,提出基于工作流的电子装配车间实时可视化、动态排程、生产过程跟踪模型;建立MES系统中工作流引擎的总体结构;并基于J2EE架构和EJB组件技术对工作流引擎进行设计实现.基于工作流的电子装配行业MES在某企业PCB装配车间应用表明,车间的生产效率和管理水平得到了显著提高.     

Effect of cycle to cycle task variations in mixed-model assembly lines on workers’ upper body and lower back exertions and recovery time: A simulated assembly study

Differences in cycle-to-cycle work content in mixed-model assembly lines (MMAL) may increase exposure to risk factors of work-related musculoskeletal disorders (WMSD). This study investigated the effect of conveyor type and product mix/sequence in MMALs on joint loads and recovery time. An assembly task was simulated using 9 conveyor (continuous moving, synchronous indexing, and asynchronous indexing) and product mix/sequence (single product, 3 products with fixed sequence, and 3 products with random sequence) configurations. Results show the self-paced conveyor resulted in the least frequency of reaching. However, subjects did not use the available time for recovery and worked at a faster pace than in the continuous and synchronous indexing conveyors. In conclusion, an asynchronous indexing conveyor provided workers the flexibility they needed to complete their job correctly without reaching but recovery time was not sufficient.Practitioner summaryCycle-to-cycle task variations in MMAL may increase workers’ risk of developing WMSDs. An asynchronous indexing conveyor, with a minimum work time built in, may allow workers to complete their job with less reaching outside the reach envelope while providing sufficient recovery time.     

A batch scheduling scheme for the workcenter that supplies parts to a mixed-model assembly line

The factory considered in this study consists of a mixed-model assembly line and a workcenter. The mixed-model assembly line (main line) simultaneously produces different product models whose assembly parts are provided in batches by the workcenter. The main purpose of this study is to develop a batch scheduling scheme for the workcenter. The objective function of the scheduling is to provide parts for the main line without delays. The problems that make the scheduling challengeable are as follows: (1) different product models being simultaneously produced on the main line require different parts and (2) space for part inventory in the workcenter is limited. This study presents two batch scheduling approaches used to build a real system for the workcenter.     

A multi-objective scatter search for a mixed-model assembly line sequencing problem

A mixed-model assembly line (MMAL) is a type of production line where a variety of product models similar to product characteristics are assembled. There is a set of criteria on which to judge sequences of product models in terms of the effective utilization of this line. In this paper, we consider three objectives, simultaneously: minimizing total utility work, total production rate variation, and total setup cost. A multi-objective sequencing problem and its mathematical formulation are described. Since this type of problem is NP-hard, a new multi-objective scatter search (MOSS) is designed for searching locally Pareto-optimal frontier for the problem. To validate the performance of the proposed algorithm, in terms of solution quality and diversity level, various test problems are made and the reliability of the proposed algorithm, based on some comparison metrics, is compared with three prominent multi-objective genetic algorithms, i.e. PS-NC GA, NSGA-II, and SPEA-II. The computational results show that the proposed MOSS outperforms the existing genetic algorithms, especially for the large-sized problems.