Information standardization in the application of PDM technology
1 Introduction
around the 1970s, CAD (Computer Aided Design) and cam (Computer Aided Manufacturing) technologies were widely used in the design and production process of enterprises. However, the application of these new technologies not only promotes the rapid development of enterprise productivity, but also brings many unexpected new problems. For example, for manufacturing enterprises, although the computer-aided technology for each department has become increasingly mature and self-contained, due to the lack of effective information sharing and utilization mechanism between them, various isolated "information islands" are often formed in enterprises. In this case, the orderly management of information has become one of the key factors for various information-based enterprises to maintain a leading edge in the fierce market competition. Product data management (PDM) technology and the corresponding application software system came into being under this background. PDM system first appeared in the mid-1980s. Its initial purpose was to solve the computer management problem of a large number of engineering drawings and technical documents in enterprises. Soon thereafter, PDM system gradually expanded to three main areas in the process of product development, namely, design drawing and electronic document management, product structure and technical status management, and engineering distribution and change management. In particular, as integrated product development (IPD) and concurrent engineering ideas are widely valued by the business community, the requirements for time coordination and schedule control of the entire product development process are increasingly strengthened, and PDM system adds the function of process management. As a management idea and information management technology that is still booming, the connotation of PDM technology has been enriched and expanded since the 21st century
2 the concept and basic principle of PDM technology and its application system
PDM is an integrated management idea and technology based on software technology and centered on products (product structure, product orders and supplier status) to manage all product related data, processes (workflow, approval and issuance process, engineering change orders) and resources. Specifically, PDM technology is a generalization and expansion of EDM (Engineering Data Management), DM (document management), PIM (product information management), TDM (technology data management), im (image management), Tim (Technology Information Management) and other product definition information management technologies. The relationship between products, processes, data and resources based on PDM technology is shown in Figure 1. It is not difficult to see from Figure 1 that PDM technology can provide information management of product life cycle, and can establish a parallel collaborative environment for product design and manufacturing within the enterprise
Figure 1 product, process, data and resource relationship model based on PDM technology
accordingly, the application of PDM technology does not increase the actual stress with the increase of external load. The part system is clearly positioned as facing manufacturing enterprises, taking products as the central content of information management, and taking data, process and resources as the three elements of information management. The two main lines of information management in PDM system are static product structure (PS) and dynamic product design process. All information organization and resource management are carried out around product design, which is why PDM system is different from other systems such as enterprise management information system (MIS), manufacturing resources planning (MRP II) Project management (PM) system and enterprise resources planning (ERP) are the key features
The basic principle of PDM system is to logically integrate all CAX "information islands", use computer system to control the whole product development and design process, and finally form complete product description, production process description and production process control data by gradually establishing virtual product model. In particular, the organic integration of technology information system (TIS) and MIS constitutes the information system supporting the whole product formation process, and also forms the technical foundation of modern integrated manufacturing system (CIMS). By establishing a virtual product model, PDM system can effectively, real-time and completely control all kinds of complex digital information in the whole product life cycle from product planning to product scrap disposal3 architecture of PDM prototype system
pdm system can integrate and manage product related information, process, personnel and organization, including four levels, namely, electronic management level of drawings and documents, department level data management level, enterprise level data management level and inter enterprise (may or may not be industry level) data management level. From the perspective of the organizational structure characteristics of manufacturing enterprises in China, data management among enterprises is one of the key issues in the implementation of PDM technology and its application system for the industry. The PDM system based on CORBA and web platform integrates the whole enterprise and spans all engineering and technical groups. It is not only the "catalyst" to promote the rapid development of products and the rapid transformation of business processes, but also the core link to directly connect with other application software systems on the basis of distributed enterprise management mode. Generally speaking, PDM prototype system is supported by distributed data processing technology in network environment, and adopts client/server, internet/intranet architecture and object-oriented design method, In "Stratolaunch began its first flight performance as early as 2019. The enterprise level realized the information management of the product life cycle, coordinated and controlled the workflow and project progress, so as to establish a parallel product development and collaboration environment throughout the enterprise. The architecture of the PDM prototype system is shown in Figure 2, including project management, workflow management, engineering drawing management, product technology status and change management, object and Image management, system integration tools and other basic functions
Figure 2 architecture of PDM prototype system
4 technical characteristics of PDM system and key problems related to product data that can be solved for information-based enterprises
from the current situation of information transformation of manufacturing enterprises in China, the informatization process of enterprises is more or less troubled by the following technical problems: first, the degree of information sharing is low; Second, the speed of information transmission is slow; Third, the business process management is backward; Fourth, the design methods and means of products are backward; Fifth, the supporting technology is not matched. The application of PDM system can not only effectively overcome the above adverse factors, but also help information-based enterprises solve the following key problems:
(1) the compression of product data. In most cases, the application of CAD and CAM technology makes enterprises "reborn" a lot of product data. These data not only occupy a large number of storage devices of enterprises, but also devour the limited network broadband resources of enterprises. In this way, enterprises not only need to constantly add new storage and networking equipment, but also lose valuable office efficiency. PDM system can compress every data entering the system to about 1/5~1/10 of the original, thus significantly saving storage resources
(2) archiving of product data. For a long time, limited by the limited functions provided by the network operating system, enterprises can only archive product data to the file server by categories, and designate special personnel to be responsible for document archiving. With the wide application of information technology, archiving operations become tedious and even unbearable. PDM system provides a more convenient product data archiving method. As long as users provide necessary engineering information, the product data can be orderly entered into the product database of the application server, so as to truly realize the product data archiving function of "who is responsible, who archives"
(3) unified coding of product data. The implementation of unified coding is the basis of enterprise informatization. Theoretically, the essence of product coding is to solve the problem of product data classification. The effective classification of product parts is exactly the main problem to be solved by PDM system. Since the previous coding standards were basically based on paper media, users usually need to read the manual and conduct manual coordination to complete a specific coding work. In this case, it is sometimes quite difficult for enterprises to implement unified coding rules. Because PDM system provides effective coding management and auxiliary generation tools, enterprises can easily define coding rules into the product database, so that users can find and browse on the network at any time. Moreover, through the code aided generation tool, the user can directly code the generated product data in the specific application software, ensuring the correctness of the coding
(4) safety problems of product data. Traditional enterprise product data is displayed on paper media. Enterprises ensure the safety of enterprise product data by formulating strict file archiving, preservation, borrowing and confidentiality systems. However, after the enterprise informatization, the electronic product data is easy to be attacked by insiders or hackers (including malicious destruction and theft). The traditional document control and management system is difficult to comprehensively solve the security problem of enterprise product data. PDM system is based on a large network database. Through dynamic role management and built-in browsing tools, it defines five permissions for users to create, browse, copy, change and delete data, which can ensure the security of data
(5) PS management problems. PS is a core concept that spans all organizational departments and business stages of an enterprise. It is the link and bridge between PDM systems and application software systems such as CAD, CAE (Computer Aided Engineering), cam, CAPP (Computer Aided Process Planning) and MRP II. Although the traditional file management method based on paper media can archive files according to PS, the concept of PS has not been effectively used. For example, the file management system based on card theory, which is popular in the market at present, can only organize data according to linear model due to the lack of the concept of product structure. PDM system takes the concept of PS as the core to organize engineering data, so that the engineering data of enterprises can show a clear hierarchical relationship under a clear PS view, which is convenient for PS based query, modification and data organization
(6) process management problems of technical departments. With the wide application of multi-dimensional (two-dimensional and three-dimensional) CAD technology, after all the drawing work of the enterprise technology department is completed on the computer, the original work driving and cooperation mode based on paper media restricts the improvement of the production efficiency of the technology department to some extent. How to find an electronic process management method suitable for enterprises has become a universal problem that information-based enterprises are facing, and it is also one of the key problems that PDM system must solve. By constructing a workflow management module for enterprise technology department, PDM system can provide a framework for information-based enterprises to customize workflow according to their own conditions. In this way, enterprises can complete the browsing and annotation tasks of the whole work process by using the embedded browsing tools
(7) retrieval of product data. In the past, the drawings, statements and documents of enterprises were kept in the archives department, and the user department had to go through corresponding procedures to get the relevant documents
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