Hybrid lean–agile manufacturing system technical facet,in automotive sector

In the automotive sector, planners have a difficult balancing act. They benefit from commonality of vehicle parts, yet they must meet more niche demands. The challenge is to strike a balance between these extremes in a cost-effective way without compromising quality. Lean strategies could increase competitiveness and profitability by reducing manufacturing costs. Concurrently, agile strategies could enable enterprises to cope with fluctuations. A hybrid lean–agile approach can be an optimal strategic blend for a manufacturing enterprise to meet this challenge. Flexible focused factory, globalized fractal E-manufacturing, innovative value chain strategies, and designing dynamic manufacturing strategies are the four technical pillars of the proposed hybrid lean–agile manufacturing system technical facet. The study shows that hybridizing the lean and agile systems together is technically valid and can be implemented in an industrial setting. It shows how strategically a hybrid lean–agile system can be implemented. It also shows that about one third of the variation in successfully dealing with the sources of competitive advantage in automotive industry can be explained by adopting the technical facet of the hybrid lean–agile manufacturing system.     

Multiple-objective scheduling and real-time dispatching for the semiconductor manufacturing system

Implementing efficient scheduling and dispatching policies is a critical means to gain competitiveness for modern semiconductor manufacturing systems. In contemporary global market, a successful semiconductor manufacturer has to excel in multiple performance indices, consequently qualified scheduling approaches should provide efficient and holistic management of wafer products, information and manufacturing resources and make adaptive decisions based on real-time processing status to reach an overall optimized system performance. To cope with this challenge, a timed extended object-oriented Petri nets (EOPNs) based multiple-objective scheduling and real-time dispatching approach is proposed in this paper. Four performance objectives pursued by semiconductor manufacturers are integrated into a priority-ranking algorithm that serves as the initial scheduling guidance, and then all wafer lots will be dynamically dispatched by the hybrid real-time dispatching control system. A set of simulation experiments validate the proposed multiple-objective scheduling and real-time dispatching algorithm may achieve satisfactory performances.     

基于对象Petri网的离散事件系统建模仿真环境(OPMSE)

首先论述了Ｐｅｔｒｉ网和高级Ｐｅｔｒｉ网发展状况,提出了一种高级Ｐｅｔｒｉ网,即对象Ｐｅｔｒｉ网。然后介绍了基于对象Ｐｅｔｒｉ网的离散事件系统建模仿真环境ＯＰＭＳＥ。文中详细介绍了ＯＰＭＳＥ的特点与组成,并对ＯＰＭＳＥ的核心－对象Ｐｅｔｒｉ网（ＯＰＮ）的语法描述进行了重点介绍。     

Discovering simulation models

Process mining is a tool to extract non-trivial and useful information from process execution logs. These so-called event logs (also called audit trails, or transaction logs) are the starting point for various discovery and analysis techniques that help to gain insight into certain characteristics of the process. In this paper we use a combination of process mining techniques to discover multiple perspectives (namely, the control-flow, data, performance, and resource perspective) of the process from historic data, and we integrate them into a comprehensive simulation model. This simulation model is represented as a colored Petri net (CPN) and can be used to analyze the process, e.g., evaluate the performance of different alternative designs. The discovery of simulation models is explained using a running example. Moreover, the approach has been applied in two case studies; the workflows in two different municipalities in the Netherlands have been analyzed using a combination of process mining and simulation. Furthermore, the quality of the CPN models generated for the running example and the two case studies has been evaluated by comparing the original logs with the logs of the generated models.     

基于分层Petri网的半导体生产线建模

论文提出了一种分层Petri网模型用于半导体生产线建模。首先,总结了Petri网在半导体生产线建模中的应用,继而给出了分层Petri网的定义及其建模过程。最后以一个典型的半导体生产线为例,进行该方法的应用研究。     

The transfer of selected lean manufacturing techniques from Japanese automotive manufacturing into general manufacturing (UK) through change agents

The North East Productivity Alliance (NEPA) has disseminated selected lean manufacturing tools and techniques into companies in the North East of England. The aim of NEPA is to help companies improve productivity through applying lean manufacturing management practices and knowledge. The Industry Forum's master class methodology is being used to transfer technology into local companies. This paper considers the process in terms of Lillrank's model of innovation transfer.

Initial results obtained from 15 companies show that the savings are eight times greater than total costs. It has been found that the commitment of management and the ability of the change agents are the key determinants of success.     

Evaluation of the role of waste in a truck manufacturing line using simulation

In their never-ending search to improve manufacturing performance, companies try to eliminate all sources of waste. In this paper, we describe how the effects of the elimination of waste on performance measures such as lead time and overtime costs can be estimated using logistical simulation. This is illustrated using a real-life case study that was conducted in the repair department of a truck cabin factory. In this department, cabs are controlled and if necessary repaired. The first part of the paper describes how bottlenecks were determined for both the present layout and for a proposed layout change. This turned out to be difficult, as several product flows intertwine. Modelling was made complex by these interactions, as they caused deadlock phenomena. The second part of the paper represents a sensitivity analysis, which evaluates the effects of different types of waste, such as machine breakdowns, inadequate buffer size and production time variance.     

Petri网模型代码映射研究

为了简化仿真系统的实现过程,分析总结了Petri网到程序代码的映射准则,从Petri网的基本元素和关系入手,根据逻辑关系建立映射的三类原子语句,并通过两种合成方式形成分子语句。以原型Petri网为例,遍历可达标识图的各种分支路径,提出循环路径到循环结构语句的代码映射方法。最后给出了带抑制弧的扩展Petri网和受控Petri网的代码映射方案,为Petri网向程序代码的转换提供了理论依据。     

基于混合编程的HPN仿真

混合Petri网（HPN）是离散事件和连续时间变量在同一层次的直接交互。其混合变迁规则较为复杂。既要考虑到离散部分与连续部分之间的相互影响，又要考虑到连续标识和离散标识之间的相互转化，所以如果选用单一语言来对混合Petri网进行仿真，难度高，编程量大，开发周期长，针对这一现象。该文提出混合编程的思想。即充分发挥不同编程语言的优势来仿真混合Petri网。该文采用了Matlab与Vc＋＋混合编程的方法来进行混合Petri网的仿真，此种方法可以很好的实现对混合Petri网的仿真，并通过混合变迁规则来验证所建HPN模型的正确性。而且由于混编的应用大大减少了编程工作量，缩短了开发周期。最后针对一个蒸发过程进行实例研究。     

Strategies of performance self-monitoring in automotive production

Production in the automotive industry, based on assembly line work, is now characterized by lean manufacturing and customization. This results in greater flexibility and increased quality demands, including worker performance self-monitoring. The objectives of this study are to refine the concept of performance self-monitoring and to characterize the strategies developed by operators to achieve it. Data were collected based on the method of individual auto-confrontation, consisting of two steps: eleven assembly-line operators of a French automotive company were individually observed and video-taped while they were working; an interview then allowed each operator to discuss his/her activity based on the video-tape. This study expands the concept of performance self-monitoring by highlighting three types of strategies directly oriented toward quality: prevention, feedback control and control action strategies.     

计算机体系结构的统一模型

提出了一种计算机体系结构的统一模型,将基于数据流计算与基于构令流计算的体系结构统一到基于指令流计算的体系结构上来,命名为Unified-ISA模型.使基于数据流计算的ASIC电路与基于构令流计算的RC Device电路的设计,统一为基于指令流计算的SIMD PE阵列上的程序设计.     

自动组合装置赋时有色Petri网模型的建立分析

半导体制造中的自动组合装置是半导体制造的关键设备和瓶颈设备.对其性能进行量化的直观的分析对于半导体制造的效率和成本预测具有重要意义.文章阐述了如何利用Aarhus大学开发的CPN Tools对单臂双处理仓的自动组合装置建立赋时有色的佩特里网模型.文中按照不同建模思想建立起抽象型和具象型两个结构不同的模型,通过比对进行验证,最后利用CPN Tools自带的仿真功能进行仿真得出模拟运行的结果.文中的研究方法和结论对于复杂的自动组合装置的有色佩特里网的分析具有一定的参考价值.     

Autonomy-subnet based structural synthesis and liveness guarantying policy of Petri net model of flexible manufacturing system

In this paper, an autonomous subnet based structural methodology forbottom-up synthesis of Petri Nets for Flexible Manufacturing Systems is proposed.Furthermore, the theoretical analysis of the model constructed by the method is carried byintensively using model's structural information, such as invariants, siphons, etc.. As aresult, the analysis leads us to draw the general conclusion that the model obtained isconservativeness and thus bound, and characterize its liveness in terms of zero-markingminimal siphons. It is based on model's structural information that distinguishes ourmethod from others. in line of this thought, a liveness guarantying policy for the obtainedmodel is proposed. Some control subnets are merged into the original model according tothe proposed synthesis rules in this paper to ensure that no minimal siphons are emptiedin any state, therefore the liveness is guaranteed. As a result, a live, conservative andrevertible Petri Nets is obtained. A practical example is also presented to