A STEP-based manufacturing information system to share flexible manufacturing resources data

The paper describes the design and implementation of a Manufacturing Information System as a solution to share and exchange manufacturing data. The Manufacturing Information System possesses relevant features for data sharing and exchanging, that are compliant to the standard ISO 10303, known as STEP¹. It is known that manufacturing planning and execution activities require data from machine-tools, robots, ASRSs², AGVs³ and, on the other hand, computer-based applications (CAM⁴, CAPP⁵ or PAC⁶) use proprietary formats to store flexible manufacturing resources data. The way the proprietary formats are built has lead to incompatibilities and interoperability problems among the applications. It is argued that by solving these problems a qualitative functional synergy will result during manufacturing planning and execution activities. The suggested solution is using a STEP-based information system, a server and a prototype client application. These three programs are implemented in Java classes to facilitate data sharing and exchanging of flexible manufacturing resources.This revised version was published in June 2005 with corrected page numbers.     

An information system for computer-integrated manufacturing systems

One of the main problems when implementing the computer-integrated manufacturing (CIM) concept concerns information integration. In order to support information integration, an information system provided with suitable data models is required. In this paper an information system is presented, which fulfils the requirements for an appropriate information management in CIM. For this purpose, an EXPRESS-oriented information system has been built on top of a commercial relational DBMS. The conceptual model of the information is built in EXPRESS and then parsed and translated to the corresponding relational constructs. A data access interface has been implemented which allows EXPRESS-oriented data manipulation. The information system was developed inside ESPRIT project No. 2202 CIM-PLATO “CIM System Planning Toolbox” to integrate the information used by the tools developed for flexible manufacturing system planning.     

The PRODNET cooperative information management for industrial virtual enterprises

When designing an IT platform aimed at supporting industrial virtual enterprises (VEs), certain issues related to information management requirements become especially challenging, such as the physical distribution of data, the enterprise autonomy and privacy enforcement, access rights to shared information, and data visibility levels, among others. In the ESPRIT project PRODNET II, a federated database architecture was designed and implemented as the base support framework to effectively manage these issues associated with the sharing and exchange of information in the VE environment. In this paper, first the general information management requirements identified for the VE network in the PRODNET II project are described, and then the challenging design issues behind the development of the components of the federated information management system are presented.     

VirtuE: a formal model of virtual enterprises for information markets

A vital part of a modern economy is an information market. In this market, information products are being traded in countless ways. Information is bought, modified, integrated, incorporated into other products, and then sold again. Often, the manufacturing of an information product requires the collaboration of several participants. A virtual enterprise is a community of business entities that collaborate on the manufacturing of complex products. This collaboration is often ad hoc, for a specific product only, after which the virtual enterprise may dismantle. The virtual enterprise paradigm is particularly appealing for modeling collaborations for manufacturing information products, and in this paper we present a new model, called VirtuE, for modeling such activities. VirtuE has three principal components. First, it defines a distributed infrastructure with concepts such as members, products, inventories, and production plans. Second, it defines transactions among members, to enable collaborative production of complex products. Finally, it provides means for the instrumentation of enterprises, to measure their performance and to govern their behavior.     

Towards an architecture for virtual enterprises

An approach to the design of an architecture for industrial virtual enterprises (VE), with special emphasis on the identification of main functional requirements, is presented. First, a discussion of the various types of virtual enterprises is provided. Some classification scenarios and discussions of the modelling and reengineering tools and methodologies are described. Due to the importance of the information flows and management in the VE, one section is merely devoted to the analysis of the appropriateness of a federated information management approach. This work is based on and represents the ongoing activities in two European Union funded projects; the Esprit PRODNET II and the INCO-DC SCM+ projects.     

The application of information systems for the design and operation of flexible machining cells

The use of information systems in manufacturing applications has dramatically changed over the last few years. The design and implementation of somewhat dated relational databases has been replaced by the generation of information models, that can be simultaneously used for the development of information systems and satisfy their integration requirements. Over the last ten years the authors have been involved in a series of research programmes focusing on the design and operation of flexible machining cells. The use of information systems has been a central theme and the enabling technology to achieve a number of novel design concepts and operational strategies for such cells. The initial research was based on the utilization of relational databases to integrate a variety of modelling and design tools. However, the additional effort required to integrate such databases to manufacturing software tools, in the form of developing file translators, information gateways and interfac es, has made the authors adopt a new approach. With this approach the information requirements are represented in a neutral format within a data model, using a formal data specification language developed by the Standards for the Exchange of Product (STEP) committee. This paper describes these changes in the design and implementation of information systems in manufacturing applications, and provides an initial view of future research requirements.     

敏捷虚拟企业组织优化中伙伴选择的建模方法

随着信息技术的发展和全球化市场竞争环境的形成,制造业的经营观念发生了深刻的改变.敏捷制造（agile manufacturing,AM）作为提高企业群体竞争能力的全新制造业生产组织模式,被认为是21世纪制造业采用的主导模式.对AM的出现和发展以及相关技术进行综述后主要讨论了在敏捷虚拟企业（agile virtual enterprises,AVE）组建过程中,支持敏捷虚拟企业（AVE）盟主进行合作伙伴选择与实现的模糊层次分析法.并对原有的层次分析法的不足做了阐述.     

A traceability information model for CNC manufacturing

This paper proposes an information model for tracing CNC manufacturing operations. The objective of the model is to assure that traceability data is comprehensive and available for every CNC machined product, independent of the relationship between the subcontractor and the contractor. The prominent feature of the model is a link between CNC report data for a product instance, the CAD design and the CAM data. This link enables users to browse the traceability data and understand the relationships between the manufacturing process, the CAD design and the CAM data. The link is independent of the systems used to build the CAD and CAM data, and allows the users to be sure the manufactured product contains the required characteristics. Then if a product instance fails, this linkage will make possible to analyze the trace data and identify any exceptions or unusual conditions in the manufacturing process.     

A PDES/STEP-based information model for computer-aided process planning

Computer Aided Process Planning (CAPP) constitutes one of the most essential elements in Computer Integrated Manufacturing (CIM). Although many CAPP systems have been reported in literature during the last two decades, few of them are compatible enough to integrate easily with other systems in the CIM environment. One major reason is the lack of an effective method to represent the information required by CAPP, and to unify such information with the information of other systems in the CIM environment. Indeed, this problem has received relatively inadequate attention in the recent research of CAPP systems. In this paper, an information model for CAPP is developed by using the object-oriented modeling and the Product Data Exchange Step/STandard of Exchange Product data (PDES/STEP) techniques. The model consists of the part information model, the process plan information model, and the production resource information model. The EXPRESS language or the EXPRESS-G diagram is used to represent these models. Indeed, the proposed information model will greatly improve the CAPP system's capability of effective integration with other systems in the CIM environment, and, ultimately, to facilitate the implementation of the whole CIM strategy in manufacturing enterprises.     

Project-driven planning and scheduling support for virtual manufacturing

The paper addresses the issue of decision-making support for small and medium-size enterprises operating within a virtual project-driven enterprise environment. The problem considered here can be defined in terms of finding a feasible schedule that satisfies the constraints imposed by the work-order duration, the price, and the time-constrained resource availability. The problem belongs to the class of multi-mode case problems of project scheduling, where finding a feasible solution is NP-hard. A heuristic method for process planning and scheduling is proposed. The method is based on a critical path approach and the branch and bound search scheme. It has been implemented in a web-enabled interactive software package, and is illustrated using the example of a virtual construction enterprise. Received: February 2005 / Accepted: January 2006     

Information fusion for simulation based decision support in manufacturing

Robust and informed decisions are important for the efficient and effective operation of installed production facilities. The paper discusses Information fusion (IF) including a generic model for IF, and situations for decision-making. The paper also discusses current and future use of manufacturing resource simulation for design/configuration, operational planning and scheduling, and service and maintenance of manufacturing systems. Many of these applications use IF in some way, as is explained in more detail for simulation based service and maintenance. An extension of the generic model for IF is presented which incorporates modeling and simulation, and active databases as used in a simulation based service and maintenance system at the authors’ laboratory.     

A decision support system for cellular manufacturing system design

With the growth of competitive pressure in the global markets, there has been an increase in demand in industry for cellular manufacturing systems (CMSs) in order to improve productivity and process flexibility. The design of CMSs for industrial applications is a complex and knowledge intensive process as it involves the consideration of many factors including production data and process characteristics. This paper describes the development and implementation of a decision support system for the feasibility and conceptual design of CMSs. The system is based on the knowledge-based system approach, and is able to make recommendations of system feasibility, cell formation techniques and cell types. A case study is also presented to demonstrate the capability of the decision support system.     

The metadatabase approach to integrating and managing manufacturing information systems

Integration has become a self-evident goal in today's manufacturing enterprises. Since the late 1970s, numerous efforts have been launched world-wide to develop, employ, and deploy integration technology as a strategic weapon to compete in the global market-place. Important results have been obtained, including computer integrated manufacturing (CIM), concurrent engineering, and enterprise re-engineering. The field is poised to tackle some fundamental barriers of integration and thereby effect a new quantum jump in overall productivity, where information will become a fourth basic factor of production along with land, labor and capital. Among the barriers are the lack of information technology enabling multiple systems operating concurrently over different geographical regions. This paper discusses a unique approach to the integration problem regarding information resources management, global query and concurrent systems administration. This approach is based on the metadatabase model which incorporates both data and knowledge in order to accomplish information integration across manufacturing functions. Basic concepts, methods and techniques have been developed for the approach and verified via a prototype metadatabase system. The system's primary components and major functionalities are discussed and illustrated in detail through the use of an extended example of a pilot manufacturing system comprising order processing, process design and shop floor control. It will also provide the reader with a simulated system demonstration.A preliminary version of this paper was presented to the Third International Conference on Computer Integrated Manufacturing, May 1992.     

A decision support tool to facilitate the design of cellular manufacturing layouts

This paper presents a decision support tool that can be used by practitioners and industrialists to solve practical cell formation problems. The tool is based on a cell formation algorithm that employs a set of heuristic rules to obtain a quasi-optimal solution from both component routing information and other significant production data. The algorithm has been tested on a number of data sets obtained from the literature. The test results have demonstrated that in many cases the algorithm has produced an exceptional performance in terms of the grouping efficiency, grouping efficacy and quality index measures. The algorithm, to an extent, overcomes common problems in existing cell formation methods such as in dealing with ill-structured matrices and achieving rational cell sizes.     

A decision support system for personnel scheduling in a manufacturing environment

A Decision Support System (DSS) is developed to support managers in the task of scheduling labor in the area of manufacturing. The DSS is designed to generate labor requirements by worker category and work center based on master production schedules. It is a PC-based, menu-driven program that generates a capacity plan based on data supplied by the user of the system.     

Internet-based manufacturing: A review and a new infrastructure for distributed intelligent manufacturing

Global competition and rapidly changing customer requirements are forcing major changes in the production styles and configuration of manufacturing enterprises. Traditional centralized manufacturing systems are not able to meet these requirements. In recent years, the internet has become the worldwide information platform for the sharing of information and data. Information processing is an important challenge in an internet-based manufacturing environment, and must facilitate distribution, heterogeneity, autonomy and cooperation. This paper reviews recent trends and major developments in internet-based manufacturing. Broad categories of distributed information management are identified, based upon the development of computer integrated manufacturing, and the possible direction of future research is indicated.     

A new generation of decision support systems for advanced manufacturing enterprises

The characteristics and environment of advanced manufacturing enterprises are analysed. A process model is briefly proposed to formulate the structured, semistructured, and unstructured decision problems. A framework for a decision support system is proposed that is capable of coordinating with the hybrid models and targeted to build an open system which can be self-organized to respond to a changing and unpredictable environment. Belief network and object-oriented technology are employed to help the system reason and reconfigure itself.     

Progress towards an international standard for data transfer in rapid prototyping and layered manufacturing

This paper discusses the informational requirements of rapid prototyping and layered manufacturing (RPLM). The study is motivated by the recent decision to embark on the development of a new Application Protocol for the international standard ISO 10303, specifically to handle layered manufacturing information.

The most common industrial use of RPLM today is for rapid prototyping, but a wider view of it as a flexible fabrication technology is taken here, to allow for future developments. Its use in building functional metallic parts under computer control has already been demonstrated, and commercial RPLM machines for building production parts are already being marketed.

The paper includes a survey of current and proposed data formats for communication between the various stages of the RPLM process. In comparing them, particular attention is given to the issue of extensibility to meet future needs. In this last respect, special emphasis is given to materials-related and other non-geometric information needed for fabricating multi-material objects and objects with graded material properties.     

A collaborative and integrated platform to support distributed manufacturing system using a service-oriented approach based on cloud computing paradigm

Today's manufacturing enterprises struggle to adopt cost-effective manufacturing systems. Overview of the recent manufacturing enterprises shows that successful global manufacturing enterprises have distributed their manufacturing capabilities over the globe. The successes of global manufacturing enterprises depend upon the entire worldwide integration of their product development processes and manufacturing operations that are distributed over the globe. Distributed manufacturing agents' collaboration and manufacturing data integrity play a major role in global manufacturing enterprises' success. There are number of works, conducted to enable the distributed manufacturing agents to collaborate with each other. To achieve the manufacturing data integrity through manufacturing processes, numbers of solutions have been proposed which one of the successful solutions is to use ISO 10303 (STEP) standard. However, adopting this standard one can recognize antonym effects of integration and collaboration approaches that weaken both integration and collaboration capabilities of manufacturing agents. In our latest work, we had developed an integrated and collaborative manufacturing platform named LAYMOD. Albeit the platform in question was through enough to be applied in various collaborative and integrated CAx systems, its embedded structure hampers its application for collaboration in distributed manufacturing systems. To achieve an integrated and collaborative platform for distributed manufacturing agents, this paper proposes a service-oriented approach. This approach is originated from cloud computing paradigm known as one of the technologies which enables a major transformation in manufacturing industry. Also, to maintain the product data integration based on the STEP standard, a new service-oriented approach is proposed. This approach is in parallel to the new capability of the STEP standard for supporting XML data structures. The result is a new platform named XMLAYMOD. XMLAYMOD is able to support distributed manufacturing collaboration and data integration based on the STEP standard. The different aspects of this platform to fulfill the requirements of distributed collaboration and also to overcome the lacks of the STEP standard are discussed through a brief case study.     

基于进程防火墙与虚拟盘的非法信息流过滤方法

提出一种在虚拟磁盘中对文件映像前后的访问进程进行监控并对非法信息流进行过滤的方法。该方法在关键字或特征信息提取过程中安装各种钩子并对接入主机进行审计,用来提高系统服务器的包转发速率与非法信息的捕捉能力。其目的是阻止病毒或木马程序对文件破坏或数据包劫持,保证信息接入的可控性和安全性。实验测试表明,系统降低了包转发时延,提高了包转发速率和非法信息的识别能力。