Product Structure And Configuration Management Based On STEP

Around the life cycle of a product, there exist a largequantity of product data of every kind. The enterprise has adopted various Computer-aided information processing systems to create, release, transfer the information automatically or mutually. But because the information models of the information processing systems are not conformable and the external data formats are not uniform, the information exchange and sharing with each other are very difficult. Along with the application of PDM system, the issue of "Information Island" among application systems has been solved in a certain degree.In recent yeas, along with the wide application of PDM technique in our country, the functions that enterprises request to PDM system are more and more advance. On one hand, the PDM system not only wants to share information with CAX, ERP systems in an enterprise, but also wants to share information with CAX, ERP, even PDM system in another enterprise. On the other hand, the requirements of each enterprise are different. In order to serve the enterprise well, a PDM system must be customized according to the special application environment of the enterprise. That needs the PDM system to have good performances of integration and opening with strong capability of data management and function expanding. This is the fact that PDM system needs further enhance.I think according to the principles of commonality, practicability and expandability, it is necessary to adopt integration, opening, and standardization as the general aims of information integration and sharing, that is adopting international standard or accepted industry standard of data express, data management, operation interface in order to form a openingenvironment. Therefore, the main idea of this paper is to apply the Standard for the Exchange of Product Model Data (STEP) that has been established by ISO to the PDM system. This primarily includes two parts: One is to establish a unified information model, which is the foundation of information sharing among systems. The other is to provide a standard mechanism for data access, which is the only way to improve efficiency of information exchange.To the first part, the main work is to establish a data model for product structure and configuration management, which is based on STEP. The objective of STEP is to provide a neutral mechanism capable of describing product data throughout the life cycle of a product independent from any particular system, while it can keep consistent and integrate when the data exchange between different systems. Product structure and configuration management is the core function in PDM system. According to product structure we can effectively organize the information about the products. Firstly In the process of developing and implementing PDM system for an architectural enterprise, we took its product as an example to analyze all the product data throughout the life cycle and have produced our information model, which was formed according to product structure. Secondly we have used the modeling method provided by STEP and withdrawn resource components from integrated resources and then modified them suit the special circumstance. So out STEP model of product structure and configuration has been completed. Finally we have described the model in EXPRESS language. Therefore The EXPRESS schema named "PDM_PSM_PCM_SCHEMA" has been established about product structure and configuration management.To the second part, the main work is to implement the Standard Data Access Interface (SDAI). SDAI defines a standard application interface for operating STEP models. It isolates the usage of data from the underlyingdata storage system. Thus, it provides the user a standard data access environment. But SDAI only offers an abstract definition of operating environment and interface functions without the detail about implementation. That means different data storage system and programming language make the SDAI implementation different. We have adopted the Oracle8i database as the und...