Performance and Evaluation of Manufacturing Systems

The monitoring and control of the input and output of manufacturing systems is an essential task for the system optimisation. Performance of manufacturing systems covers a wide spectrum of technology and management activities. This paper reviews the historical evolution of and modern developments in manufacturing performance measurement within a systems framework based on five metrics and five levels from single workstation to the entire manufacturing network. A summary of an industrial survey in the aerospace industry is also included to provide an industrial perspective. The implications of emerging topics of growing importance in sustainability, agility, e-manufacturing, complexity and biomimetics are also discussed.     

Reusability Assessment for Manufacturing Systems

Manufacturing firms have begun reconfiguring and reusing production systems to save resources consumed on system changes that were brought about by the high product variety and frequent model change. As a result, assessing manufacturing system reusability has become an important issue. This paper introduces intrinsic and effective reusability of manufacturing systems and proposes quantitative metrics to assess them. Using an automotive assembly system as example, this paper also explores how system configurations and task allocation affect reusability. Insights from such a study will help improve manufacturing system reuse for families as well as generations of products.     

Convertibility Measures for Manufacturing Systems

With increased consumer demands for a wider variety of products In changeable, unpredicted quantities, manufacturing system responsiveness has become increasingly Important for Industry competitiveness. Manufacturers need systems that can be rapidly adjusted with regard to both functionality and throughput capacity over the lifetime of the system. Convertibility is defined as the capability of a system to adjust production functionality, or change from one product to another. End-users of manufacturing systems are struggling with the Issue of how to measure and quantify convertibility. Metrics for convertibility are proposed in this paper so that different manufacturing systems can be compared with respect to this area of performance. These metrics are based on assessments of the configuration itself, and the system components such as machines and material handling devices. Metrics for quantifying convertibility are useful for comparing system configurations during the early phases of design, with out requiring detailed product or process plan Information.     

Stochastic Optimal Capacity Management in Reconfigurable Manufacturing Systems

This paper presents an optimal policy, based on Markov decision theory for the capacity management problem in a firm facing stochastic market demand. The firm implements a reconfigurable manufacturing system and faces a delay between the times capacity changes are ordered and the times they are delivered. Optimal policies are presented as optimal boundaries representing the optimal capacity Expansion and reduction levels. TO increase the robustness of the optimal policy to unexpected events, the concept of feedback control is applied to address the capacity management problem. It is shown that feedback provides sub-optimal solutions to the capacity management problem which are more robust under unexpected disturbances in market demand and unexpected events.     

Configuration of Manufacturing Cells for Dynamic Manufacturing

Classical approach to the formation of manufacturing cells is based on the application of similarity principles to a binary machine-part matrix. This approach ignores volume effect as well as dynamic demand pattern. This paper first identifies and characterises the volume effect based on two measures of manufacturing cell efficiency, i.e., average job flow time and total intercell travelling time. The effect of similarity coefficient threshold value on cell configuration based on binary and volume data was evaluated and tested statistically. Finally, the implication of cell configuration on systems performance under dynamic demand pattern is discussed with an example based on 80 machines and 820 parts.     

制造系统组态的最优成本分析

制造系统组态随着机床数的增加呈几何级数增加,任一种组态都可以看作是最基本组态——串联组态的合成,本文针对串联组态的加工制造系统,在可靠性约束和加工能力约束下建立成本最优模型,并在AMPLF对实例进行求解。进而为以后的可重组制造系统环境下的标准模块化组态选择打下基础。     

A Deadlock Handling Method for Automated Manufacturing Systems

Deadlock-free operation is a principal requirement for an automated manufacturing system. The part types passing through the manufacturing system are characterized by the sequence of the manufacturing resources required for their completion. The method partitions the sequence into alternate subsequences consisting of deadlock-free resources and deadlock-risk resources. The set of deadlock-free resources is shown. The proposed method introduces a novel structural on-line control policy which guarantees that the execution of an operation representing an elementary step of a job relating to a part does not lead to deadlock. The proposed policy is suitable for implementation in modern distributed manufacturing control systems due to the low on-line computational costs.     

Measuring Flexibility in Investment Decisions for Manufacturing Systems

Investment decisions for manufacturing systems are primarily based on three characteristics: cost of purchase and operation, cycle time in connection with maximum capacity and achievable work piece quality. However, such considerations neglect another important criterion: the flexibility that allows a manufacturing system to adapt to future production requirements and structures. The major barrier in integrating flexibility into the decision-making process is the difficulty to measure and compare it due to upcoming production scenarios that are not ultimately definable. Therefore, this paper presents a methodical concept for the evaluation of manufacturing systems using real options in order to incorporate flexibility in the decision-making process.     

Agent-Based Systems for Manufacturing

The emerging paradigm of agent-based computation has revolutionized the building of intelligent and decentralized systems. The new technologies met well the requirements in all domains of manufacturing where problems of uncertainty and temporal dynamics, information sharing and distributed operation, or coordination and cooperation of autonomous entities had to be tackled. In the paper software agents and multi-agent systems are introduced and through a comprehensive survey, their potential manufacturing applications are outlined. Special emphasis is laid on methodological issues and deployed industrial systems. After discussing open issues and strategic research directions, we conclude that the evolution of agent technologies and manufacturing will probably proceed hand in hand. The former can receive real challenges from the latter, which, in turn, will have more and more benefits in applying agent technologies, presumably together with well-established or emerging approaches of other disciplines.     

Modelling of Manufacturing Systems Complexity

This research aims at understanding the effects of human worker attributes within the manufacturing system. The system must balance human characteristics, needs, skills and capabilities within the technical and business environment, in order to be effective. A model is needed to provide insights into the sensitivities of the manufacturing system. A methodology to systematically determine the product and process complexity for any manufacturing environment was introduced - a rapid Manufacturing Complexity Assessment Tool (MCAT). The complexity model is based on three elements: total quantity of information, diversity of information and the information content which corresponds to the effort to produce a feature within a product. Product and process complexity are decoupled and treated independently in this analysis. An example is presented to illustrate the methodology for both. The purpose is to develop a tool that helps to identify areas of complexity that can be simplified.     

可重构制造系统的组态设计研究

针对可重构制造系统（RMS）的组态设计问题,以现有的制造资源为基础,分析了RMS中机床设备与加工成本的组成要素,构建了RMS的生产周期成本模型.引入图论的方法,构建了RMS在生产周期组态的有向网络图,从而可把k-优组态转化为在有向网络图中求解k最短路径问题,运用DoubleSweep算法与反向追踪法分别搜索有向网络图的k-优生产周期成本及其对应的k-优组态.最后,用仿真实例验证了方法的有效性.     

加工系统的机床组态能力及其可靠性分析

在不考虑成本因素以及其它影响因素的条件下，运用矩阵和概率理论，从机床级可靠性出发，研究了四台机床所组成的生产线的组态能力及其可靠性。     

Operation of Manufacturing Systems with Work-in-process Inventory and Production Control

The operation of large manufacturing systems with buffers has two goals: to meet production target and minimize the work-in-process (WIP) inventory. This paper introduces a novel approach, based on optimal control theory, to achieve both goals simultaneously by on-line adjustment of the production rate of each machine. In this method the state variables are the buffer levels, the control variables are the machine production rates, and the output variable is the target production (the demand). The method is evaluated through simulations under various conditions, and compared with other methods in the literature. The results demonstrate that the proposed method can successfully produce low WIP inventory than other methods, while the required production demand is still fulfilled. It is also shown that the method is capable of providing feasible solutions for large manufacturing systems - a goal that is harder to achieve with the current known method.     

离散型制造业MES的深入研究

在研究制造执行系统（MES）和准时化生产（JIT）的诸多文献中，缺少分析两者联系与区别的文章。论文通过对MES与JIT多方面的比较分析，提出两者实质相同的观点；并进一步将其结合在一起，提出了广义制造执行系统的概念。     

Integrated Virtual Manufacturing Systems for Process Optimisation and Monitoring

The implementation of an Internet-based Virtual Manufacturing facility for the development and optimisation of new manufacturing processes is presented. The facility integrates advanced process simulation software, a remote machine monitoring system and multimedia technologies to realise a virtual environment for manufacturing process optimisation. Utilising physics-based process simulations, process parameters and operational sequences are evaluated and optimised with respect to desired product features. Having optimised the operation, a prototype of the part can be created at the facility. During prototyping, process parameters are monitored in real-time. A Case Study is presented, where a 3-axis milling operation is defined, optimised and executed using the facility.     

A Design Method for Product Family under Manufacturing Resource Constraints

Product variety is required for satisfying customer needs, and at the same time, efficient usage of manufacturing resources is mandatory for competitive and environmentally conscious manufacturing. For coping with these requirements, product family concept is effective, which enables variety of products based on well designed similar product property with associated manufacturing processes. In this study, a modeling framework for relationship between product functionality and manufacturing resources is discussed. Based on this framework, a design method is investigated for product family structure which realizes required product functional variety with efficient utilization of manufacturing resources. Application examples are discussed for automotive components.     

数字制造中制造信息的关键技术研究

制造信息是制造系统的核心。制造信息学为数字制造研究提供了，一种新的方法。根据现代制造业的发展趋势，本文给出了制造信息学的有关定义和制造信息学理论的体系结构，分析了数字制造对制造信息系统的基本要求，讨论了制造信息学与数字制造的一些关键技术。     

A new Fuzzy AHP method for the Evaluation of Automated Manufacturing Systems

The decision on production system acquisition for the automotive industry is very critical, given the number of different aspects to be considered. Indeed different automated solutions are feasible and evaluation techniques that take into account all the critical issues are needed to make a selection. In this paper a complete, precise and value driven Decision Support System is presented to support the selection of the best Automated Manufacturing System. The evaluation problem is solved using a Fuzzy Analytic Hierarchy Process (AHP) method able to manage uncertainty and to consider productivity and flexibility issues. Economic and financial performance and the effects on human resources due to the investment decision are also investigated.     

制造网格中制造资源的多视图模型研究

对制造网格中的制造资源进行了功能分类,在此基础上,分别从不同的角度对制造资源进行分析,建立了包括信息模型、数据模型、结构模型和管理模型的制造资源的多视图模型,分析了这几个资源模型彼此之间的联系。该模型为开发制造网格中的制造资源管理系统原型,实现全局范围内制造资源的全面共享奠定了基础。     

The Korea Advanced Manufacturing System (KAMS) Project

The Korea Advanced Manufacturing System (KAMS) is one of the Highly Advanced National (HAN) Projects planned to achieve significant technological advances in Korea. The aim of this project is to create new processes and technologies for managing and integrating manufacturing systems. The key to sustaining economic growth and surviving global competition is to develop advanced manufacturing systems technology. The Korea Institute of Industrial Technology (KITECH) began this project in 1992 with support from the Ministry of Trade, Industry and Energy and the Ministry of Science and Technology. The project is divided into three phases, each phase consisting of project groups which include several research projects. The main project groups are ‘next-generation machining system' and ‘assembly and inspection system for electronic products'. The names of research projects are listed, and brief explanations are also introduced in this paper. The KAMS Project is expected to result in many benefits for manufacturing industry. The increase in productivity and system accuracy, and reduction in lead-time, will give renewed vitality to Korean manufacturing industry.