Research on Application System Integration of Manufacturing Enterprises Based on PLM

With the development of information technology, manufacturing companies are also undergoing tremendous changes. At present, there are more and more application software used by manufacturing companies, such as CAX (CAD, CAM, CAPP and CAE), PLM and ERP technologies are also continuously promoted and applied. These applications have heterogeneous environments for handling heterogeneous information in product definitions, process descriptions, and production controls, and store various data information in separate physical systems, which makes them urgently required to implement each network. The integration of enterprise application systems to share and integrate information between enterprises. However, the information systems and databases of different enterprises are not the same, which brings problems to the sharing and exchange of information. For this purpose, this paper proposes an integration of PLM-based inter-enterprise systems to realize the sharing and integration of enterprise information.

1 The necessity of implementing application system integration based on PLM

Manufacturing system integration is a system integration based on the information model of the product life cycle. All product data in the product life cycle is defined, and these data are stored in different application systems. In order to make the product information model transparent to all users, these distributed systems must be integrated into one. These systems mainly include CAX, PLM and ERP. The necessity of integration based on PLM system can be summarized as the following three aspects:

First, the focus of each system is different throughout the product life cycle. CAx systems are primarily used for product design, analysis, and manufacturing. PLM systems are used to manage product-related data and processes, while ERP systems focus on management. Enterprise resources of people, finance, materials, information, etc. Secondly, due to the different application scope and different focuses of these systems, the inconsistency of their information models has caused “information islands” between application systems, and has not realized enterprise information resources. The maximum reuse and sharing is a waste of information resources for enterprises; finally, the realization of product life cycle management is the main development direction of enterprise information. Any single system existing can not complete the entire product lifecycle management of the manufacturing enterprise, so it is necessary to use the existing information resources of the enterprise for system integration, which is also an economically feasible way to achieve.

2 Based on the PLM application system integration framework

2.1 System integration needs to be considered

When an enterprise integrates an application system, it must consider not only the technical factors of the existing system, but also the organizational structure, staffing, technical conditions, and integration costs that the enterprise can bear. The higher the integration, the higher the cost, and the greater the impact on the business-related business units. In general, system integration requires several considerations: first, to define the data of an object, the information definition and description in different application systems are not the same, and the data must be uniformly defined and described. The second is the control of the data, which data is generated by which people. And who controls the information resources that need to be shared; finally, the implementation of heterogeneous computer application system integration.

2.2 Structural framework of system integration

According to the different ways of system integration, this paper proposes the PLM application system integration framework of PLM. The system framework is described in detail below.

CAX systems are characterized by diversity and heterogeneity, and different PLM systems use different system architectures and external interfaces. Therefore, Web-based platform-independent technology must be adopted to realize the integration of general CAX and PLM systems. Since WebService is completely independent of the Web platform, it defines the application's communication on the Web, and has nothing to do with the underlying implementation of each application. Therefore, the Web Service platform is selected to realize the integration of CAX and PLM system. The requirement of platform independence makes it necessary to shield the underlying implementation details of different systems. Different systems provide a unified calling interface. The Facade design pattern has the above advantages. Therefore, the underlying interfaces of CAX and PLM systems are packaged into Webs using Facade mode. The Service, in order to shield the respective underlying interfaces from the outside, exposes only the APIs required for calling each other. The PLM system can invoke the Web Service that encapsulates the CAX interface through the Web. Conversely, CAX can also call the PLM WebService, which is called by the web and the relationship is equivalent. The PLM system and the CAX system are the client and server side of the Web Service, and the client and the server communicate using the SOAP protocol. The two systems use XML format for information exchange, and each of them converts the internal data format into an XML data format transmission request through the data exchange encapsulation interface. After receiving the XML format data, the received XML is also received through the data exchange encapsulation interface. The data is parsed into their respective internal formats.

The most important data integration of ERP and PLM integration is BOM. A product must be engineered, process design, and manufactured to form a product. The BOM is also transformed from the engineering bill of materials EBOM to the manufacturing bill of materials MBOM. In PLM, the BOM is expressed in the form of a product structure tree, which mainly includes material information and product structure information, which are data that PLM needs to import into ERP. In ERP, the most fundamental role of BOM is to calculate the material requirements, costs, capabilities, and so on. To achieve a unified integration, we must first resolve the inconsistency of the BOM table. We can establish the equipment BOM (ABOM) as an intermediate stage of the two, including not only the product assembly files, but also the product process equipment, consumables, special tools and technical documents. Since PLM and ERP are often from different manufacturers, it is an effective way to apply XML for BOM information delivery. Through the API set provided by the ERP system and the PLM system, the information that the system needs to provide is imported or exported, and converted into a unified XML file for information transmission.

3 Key technologies for system integration

3.1 Web Service Technology

Through Web services, enterprises can publish shared information and external information, and their information can be used by Web programs or by other enterprise applications. The web service features are as follows.

1) Perfect encapsulation, for the user, it can and can only see the list of functions provided by the object.

2) Loose coupling For loose coupling, especially for Web services in the Internet environment, there is a need for a message exchange protocol suitable for the Internet environment. XML/SOAP is currently the most suitable message exchange protocol.

3) Software platform independence, highly integrated capabilities.

The Web Service platform was chosen as the integration platform for PLM and other system integration frameworks. The platform is a set of standards and protocols to ensure dynamic connectivity between programs. The most basic protocols include: SOAP, WSDL, UDD I. SOAP (Simple Object Access Protocol) is a protocol for web services message communication, which is the core content; WSDL (Web Services Des cription Language) is a Web service definition language used to describe SOAP messages and how to exchange these messages; UDDI (Universal Des cription, Discovery, and Integration general purpose discovery, description, and integration) is used to centrally store and find WSDL description files, and acts as a directory server. After the underlying interface is encapsulated, the web service application is written on the unified high-level data exchange interface. Since different systems provide a unified high-level data exchange interface, the Web Service only interacts with the high-level data interface, so a general Web Service service can be written. The program is applied to the integration of different CAPP and PDM systems. By writing a common Web Service application to PLM and other systems, the web service is called on the Web to realize seamless integration of PDM and other systems.

3.2 XML technology

Since CAX (CAD/CAM/CAPP) and ERP and other systems have different data formats, an intermediate common data format must be provided to achieve information integration between the two systems.

As an efficient, simple and highly open, compatible and cross-platform performance data storage and data exchange standard, XML has increasingly shown its superiority. The main advantages of XML are:

(1) A good data format facilitates the design of markup languages ​​associated with a particular domain, while facilitating data exchange between heterogeneous systems.

(2) Good scalability and flexibility XML's extensibility and flexibility allow it to describe data in different kinds of application software, and can integrate data from different sources to facilitate data creation.

(3) It is convenient for network transmission XML to have good compression performance, and does not add too much burden to network transmission.

(4) Document highly structured XML through the custom identity, the document is decomposed into elements with a certain meaning of the mark, and each element can be attached with additional information (attributes), thus becoming a hierarchical data structure. Since XML has so many advantages, XML is selected as an intermediate format to implement data exchange between PLM application system integration. Each independent system converts its own data into an intermediate format such as XML, and realizes data exchange and information sharing through the integration framework, realizing the platform independence and strong portability of the integration framework. Let us take the data exchange between CAPP and PLM system as an example: CAPP and PLM system exchange data in the form of BOM. CAPP obtains EBOM and its attributes from PLM system. The main exchange data between CAPP system and PDM system is BOM (Bill Of Material), CAPP obtains design BOM and design attributes from PDM, and PDM gets process from CAPP. BOM and assembly BOM, the product structure tree is the central content of the BOM. Here is an example of a product structure tree implemented in XML:

The data exchanged between the systems is all encapsulated into an XML format, and the XML format and the internal data format are mutually converted through respective data exchange encapsulation interfaces.

4 Conclusion

With the further development of informatization, the information integration of manufacturing industry will become an imperative development trend, making full use of limited enterprise resources and maximizing the utilization of resources. It is also the design of each designer and enterprise manager. wish. Through the integration of PLM-based enterprise applications, this paper combines design, analysis, manufacturing and management to achieve a certain degree of information sharing and exchange. Due to the complexity of the system, there are still some aspects of this solution, such as service security, which need further exploration and research.