云计算环境下动态虚拟企业伙伴选择模型

互联网内海量的企业信息检索以及虚拟企业UDDI的搭建和管理已成为中小型企业组建虚拟企业的严重障碍。云计算通过互联网络提供虚拟化的资源计算模式,使企业能够快速部署资源和获取信息服务,从而使中小企业以快速和较低的成本创建企业联盟,争取主导地位成为可能。提出了一种云计算环境下动态虚拟企业伙伴选择模型,采用并行筛选机制降低问题求解空间,实现了中小企业联盟海量伙伴选择和UDDI搭建等问题,并通过实验验证了模型的合理性和可行性。     

虚拟企业模型并行仿真研究

随着各种全新的制造理念,特别是虚拟企业的出现,企业模型的规模不断扩大,使目前存在的大多数企业模型仿真系统的效率大大下降。该文针对此问题,通过深入分析虚拟企业模型结构,并在已有的构件化企业建模体系CEMS及其仿真系统的基础上,结合异步仿真技术和多线程技术提出了一种分层式企业模型仿真体系结构,为虚拟企业模型的快速高效的仿真提供了一种有效的方法。     

基于Internet虚拟企业的ASP框架模型

阐述了在虚拟企业环境中实现ASP（Application Server Provider)的框架模型，分析了其实现机理，并制作了一个用于CAD图形文件格式转换的虚拟环境下的ASP服务系统的原型系统。在虚拟企业环境中，企业之间的服务功能是虚拟企业的关键问题，为之提出了具体的实现框架和实现过程。作为原型系统，建立了一个基于Internet的CAD图形文件转换服务系统，可以提供IGES／STEP／VDA／VRML／prt等文件格式的转换服务。     

并行环境下广义装配设计的集成框架

提出了以装配建模和变量设计为核心,以装配规划与仿真,装配分析和公差分析与综合等为支撑的广义装配设计的集成框架,该框架能在并行工程的环境下对产品设计进行信息集成和设计过程集成,形成自上而下的,各支撑系统模块间相互依存,相互评价的设计循环,从而提高产品的一次设计成功率。     

基于Multi-Agent的虚拟企业集成框架研究

本文采用多智能体技术构建虚拟企业集成框架 ，在该框架中，由agent代表各成员企业，相应地，多智能体系统(Multi-Agent System)代 表虚拟企业．其中重点提出了agent通用结构，它包括核心层、接口、通讯层三个组成部分 ：核心层由企业的原有系统构成，以保证企业的自治性；接口实现了agent核心层与通讯层 之间的信息交换；通讯层则支持agent之间的交互，实现企业间的合作．该虚拟企业集成框 架不仅支持虚拟企业像一个企业一样进行工作，而且实现了虚拟企业的可重用、可重构和可 扩充，并使企业根据需要同时参加多虚拟企业成为可能．     

虚拟企业环境下通用Web数据库应用程序的设计

虚拟企业的敏捷性和动态重组的特性要求实现信息重组,当前基于Ｉｎｔｅｒｎｅｔ的数据处理并不能满足。文中依托ＶＥＩＭ,通过ＤＢ_ＸＭＬ标识以及ＶＥＲ的注册库信息,由ＣＭ生成的通用Ｗｅｂ数据库应用程序具备适应对多异构数据库交互访问能力,与搜索引擎组合实现在 Ｉｎｔｅｒｎｅｔ网上的信息重组。     

基于遗传算法的虚拟企业局部模型划分方法

局部模型的划分是分解、简化敏捷虚拟企业建立过程决策问题的重要方法，划分结果可能直接影响到敏捷虚拟企业的建立方式、伙伴企业的合作方向和虚拟企业模型的优化,由于该过程涉及到复杂的组合优化问题以及定量评价方法，因此对该问题的求解具有很高难度。本文提出了应用遗传算法为主的算法来优化这一项目划分过程的方法，该方法根据问题的特点采取特定的基因编码、遗传与变异算子等，本文最后依据一个实际算例来说明和验证该算法。     

基于任务结构模型的多Agent产品并行开发体系

为了促进产品并行开发,文章提出了一种用于描述基于领域的任务分解、任务之间的约束关系及任务与产品信息之间对应关系的任务结构模型,设计了表示语言ＣＲＬＥ以定义领域共享本体论和任务结构模型。在此基础上构建了多Ａｇｅｎｔ产品并行开发体系,包括由多个协作Ａｇｅｎｔ和一个协作促进器组成的Ａｇｅｎｔ联邦、系统服务Ａｇｅｎｔ和领域服务Ａｇｅｎｔ,并提供了协调机制。     

虚拟企业环境下企业生产计划与控制系统的研究

生产计划与控制系统在企业的运行中起着非常重要的作用。现有的企业生产计划与控制系统已不能满足虚拟企业环境下的需求,如自治性、分布性、动态性与异构性。在对虚拟企业环境下对企业生产计划与控制系统的需求进行分析的基础上,使用Multi-Agent技术,给出了基于Multi-Agent的适应虚拟企业环境的企业生产计划与控制系统的实现方法。该方法通过对企业原有生产计划与控制系统的改进,能广泛提高企业的性能,如缩短交货期、提高资源利用率、降低成本等等,同时节省了企业生产计划与控制系统重新设计的费用。     

并行工程下产品协调模型的研究

建立和维护产品全生命周期中各种应用活动之间动态的信息关联,是实现产品数据集成、保证各应用领域协调活动的关键,为此,提出了基于产品设计过程的产品协调模型,该模型将原用于基于历史的几个何特征建模的特征编码作为建立和维护产品几何信息及其它应用信息间关联的纽带,为了屏蔽特征编码机制的私有属性,建立了比特征编码机制更高层的协议－数据协调协议,该协议为在产品几何信息与非几何应用信息之间建立和维护动态的、协调一     

Development of a framework system for tool integration in a product information archive

The described framework system has the goal of providing an integration platform for engineering tools to interact. Engineering tools exchange information via the data repository of the framework system. In the European research project ESPRIT EP6896 Concurrent/Simultaneous Engineering System (CONSENS), a Product Information Archive (PIA) is being developed based on the object-oriented database system of the framework, the Object Management System. The Product model is based on a STEP compliant schema. This has been achieved by developing an Application Resource Model (ARM) for the required product information according to a user requirements analysis. The ARM then was mapped to the Integrated Resource Models of STEP which resulted in an object-oriented STEP compliant model. The main objective of PIA is the integration of the product information flows between parallel teams using the framework for product development. This is provided by an interface consisting of a library of functions that enable tools within and external to the framework to access PIA and exchange up-to-date product information. Additionally an X Motif based interface provides human users with direct access possibilities. The framework has been tested by the integration of various tools which support product development.     

Enabling allied concurrent engineering through distributed engineering information management

The management of engineering information to ensure that the right information is quickly provided to the right place at the right time in the right format is one of the most critical tasks in the engineering process. Within the practice of allied concurrent engineering, the importance and difficulty of engineering information management is increased due to the issues of inter-enterprise communication and process control, system heterogeneity, information and system security, differing engineering data formats and multi-database formats. This paper presents an engineering information management approach for the practice of allied concurrent engineering (ACE). An ACE-based engineering information management methodology is proposed under the concept of enterprise integration. This methodology includes an information management life cycle, a distributed management framework, and rules and methods for information management. Based on this methodology, an ACE-based engineering information system was developed using Unified Modeling Language (UML) modeling techniques. The result of this research will enable the practice of allied concurrent engineering and consequently help increase product development capability and quality, reduce development cycle time and cost, and hence increase product marketability.     

A decision support system for product design in concurrent engineering

Compared with the traditional sequential design method, concurrent engineering is a systematic approach to integrate concurrent design of products and their related processes. One of the key factors to successfully implement concurrent engineering is information technology. In order to design a product and its manufacturing process simultaneously, information on product features, manufacturing requirements, and customer demands must be processed while the design is concurrently going on. There is an increased understanding of the importance of the correct decisions being made at the conceptual design and development stages that involve many complex evaluation and decision-making tasks. In order to promote the efficiency in concurrent product development, appropriate evaluation and decision tools need to be provided. In this paper, the characteristics of fuzzy, multi-stage evaluation and decision making in concurrent product development process are analyzed and a decision support system for product design in concurrent engineering is presented. An example is given to illustrate the application of the system.     

Product relationships management enabler for concurrent engineering and product lifecycle management

The current competitive industrial context requires more flexible, intelligent and compact product lifecycles, especially in the product development process where several lifecycle issues have to be considered, so as to deliver lifecycle oriented products. This paper describes the application of a novel product relationships management approach, in the context of product lifecycle management (PLM), enabling concurrent product design and assembly sequence planning. Previous work has provided a foundation through a theoretical framework, enhanced by the paradigm of product relational design and management. This statement therefore highlights the concurrent and proactive aspect of assembly oriented design vision. Central to this approach is the establishment and implementation of a complex and multiple viewpoints of product development addressing various stakeholders design and assembly planning points of view. By establishing such comprehensive relationships and identifying related relationships among several lifecycle phases, it is then possible to undertake the product design and assembly phases concurrently. Specifically, the proposed work and its application enable the management of product relationship information at the interface of product-process data management techniques. Based on the theory, models and techniques such as described in previous work, the implementation of a new hub application called PEGASUS is then described. Also based on web service technology, PEGASUS can be considered as a mediator application and/or an enabler for PLM that externalises product relationships and enables the control of information flow with internal regulation procedures. The feasibility of the approach is justified and the associated benefits are reported with a mechanical assembly as a case study.     

A toolset for building the virtual enterprise

Much research has been undertaken to define what a virtual enterprise is and how it should work. This paper addresses the specific question, how a virtual enterprise can be designed to have the agility to support short-term business opportunities. A framework is presented for the organizational design and the changing business roles of the business architect who constructs the various phases of the virtual enterprises lifecycle. This infrastructure for creating virtual enterprises is referred to as the value system designer; a set of methods and tools to select partners, re-engineer business- and logistic processes and to set up an information and communication platform for the virtual enterprise. The methods and tools have been developed in two longitudial research projects TELEflow and the Virtuelle Fabrik between 1995 and 1999. Focusing on the experiences gained from numerous cases, a summary on crucial success factors for designing virtual enterprises shall be presented. Thus, this paper gives insights and applicable know-how for companies and managing engineers in their role as virtual enterprise architects, for example leaders of project consortia or joint ventures or as first-tier suppliers co-ordinating supplier (sub-) nets.     

The use of semantic networks to support concurrent engineering in semiconductor product development

The design of semiconductor devices is an extremely complex and costly process. Numerous design and test iterations are typically necessary to finally complete a successful device. Competition in the industry has forced semiconductor manufacturers to reduce design cycle times and costs. One method now being used to accomplish these objectives is concurrent engineering. This paper will review how concurrent engineering is being integrated into semiconductor device development and how artificial intelligence-based models will support concurrent engineering implementation. Major changes are needed in design simulation, methods of knowledge sharing, and incorporating best practices. A semantic network is proposed that retains the knowledge of a product in a central repository as various engineers contribute to the product's development. The knowledge contained in this central repository can be referenced for applicability by engineers during product design, development, and production.     

A versatile virtual prototyping system for rapid product development

This paper presents a versatile virtual prototyping (VP) system for digital fabrication of multi-material prototypes to facilitate rapid product development. The VP system comprises a suite of software packages for multi-material layered manufacturing (MMLM) processes, including multi-toolpath planning, build-time estimation and accuracy analysis, integrated with semi-immersive desktop-based and full-immersive CAVE-based virtual reality (VR) technology. Such versatility makes the VP system adaptable to suit specific cost and functionality requirements of various applications.

The desktop-based VR system creates a semi-immersive environment for stereoscopic visualisation and quality analysis of a product design. It is relatively cost-effective and easy to operate, but its users may be distracted by environmental disturbances that could possibly diminish their efficiency of product design evaluation and improvement. To alleviate disturbance problems, the CAVE-based VR system provides an enclosed room-like environment that blocks out most disturbances, making it possible for a design team to fully concentrate and collaborate on their product design work.

The VP system enhances collaboration and communication of a design team working on product development. It provides simulation techniques to analyse and improve the design of a product and its fabrication processes. Through simulations, assessment and modification of a product design can be iterated without much worry about the manufacturing and material costs of prototypes. Hence, key factors such as product shape, manufacturability, and durability that affect the profitability of manufactured products are optimised quickly. Moreover, the resulting product design can be sent via the Internet to customers for comments or marketing purposes. The VP system therefore facilitates advanced product design and helps reduce development time and cost considerably.     

Re-engineering of the design process for concurrent engineering

According to the requirements of concurrent engineering, three interdependency relationships (uncoupled relationship, coupled relationship and decoupled relationship) between design activities are presented in this paper. And the coupled relationship plays an important role in concurrent product design process. To represent the precedence relationships among design activities, a directed graph is used to describe the design process. And the interdependency relationship between activities is illustrated by a Design Structure Matrix which is the transpose of the accessibility matrix of the corresponding graph. Using the DSM, an algorithm of recognizing the coupled activities during the design process is presented. Moreover, an algorithm to figure out the order levels of activities during the design process is proposed. And both algorithms are illustrated with a die design example.     

Modeling evolving product data for concurrent engineering

In order to make the traditional product structure tree representation amenable to concurrent engineering relationships likeperspective-of anddependent-on have to be added to the essentialpart-of relationship. Complex data can be held in proprietary formats, while simple data will be in a common representation for direct access by diverse disciplines. Coordination among team members in a project can be carried out using such a model. Besides, a virtually unified view of all the data is possible, though they may lie in distributed and heterogeneous data bases. A very necessary characteristic of such a model is that its time evolution should be easy to represent in order to reflect the dynamic nature of product development, where the model itself, and not merely the data values change. Managing versions is also facilitated by the comprehensive structure of the Unified Product Data Model (UPDM).     

Collaboration planning framework (CPF) to support distributed product development

Current marketplace is undergoing major changes that will affect the way organizations conduct their business. Organizations need to respond to a geographically dispersed marketplace. This can be achieved by leveraging globally distributed resources to fully understand and interpret individual customer needs. That is, organizations need to integrate their operations (product development) in a way that will allow dynamic response to market changes. Computer-supported collaborative engineering could provide the integrating mechanisms needed to integrate distributed operations. The change to collaborative engineering should be based on sound and comprehensive methodologies that can analyze current practices, assess their ability to be performed collaboratively, restructure organizational practices to enhance their performance in a collaborative environment, select appropriate tools to support practices, and provide an implementation plan. This paper presents a framework to build computer-supported collaborative product design and development operating in a distributed environment. The framework is composed of six modules that provide a systematic procedure to plan for computer supported collaborative engineering.