Foreword
With the spread of the Internet, the globalization of markets and business activities will further develop, and it will affect every manufacturing company and become a force for change. Today, you can transmit and receive a wide variety of information anywhere in the world. The main obstacle to accessing global information today is the backwardness and ignorance of ideas, not the lack of communication infrastructure. The universality and distribution of information pose new challenges for manufacturing companies.
The advantage of inter-enterprise competition is no longer just relying on technology. This requires companies to strengthen the possibilities of cooperation and globalization. An enterprise is connected by the Internet, and an organization composed of multiple organizations can share knowledge and resources and provide a product or service. This kind of collaboration and alliance can maximize their respective advantages, and by providing comprehensive solutions to customers, they can achieve each alliance partner's own goals while better meeting the overall needs of customers.
Product Data Management (PDM) is a technology based on software technology, with products as the core, and integrated management of data, processes and resources related to products. PDM is clearly positioned as a manufacturing enterprise, with products as the core of management, with data, processes and resources as the three elements of management information. The traditional PDM is mainly for the internal data management of enterprises. There are some shortcomings in the information communication, user friendliness and maintenance complexity between enterprises. The application of Web technology in PDM system can solve these problems well.
In the past research, the Web-based PDM system is generally divided into three layers, the client layer, the Web service layer, and the database service layer. In this paper, the Web service layer is divided into the system service layer and the system application layer, where the system service layer is passed. Internal and external interfaces provide different services. Therefore, this paper proposes a four-layer framework for Web-based PDM systems.
Problems with traditional product data management systems
1. 1 Lack of cross-enterprise, cross-regional, global communications
In today's economic globalization, project teams can be scattered around the world. How to coordinate the relationship between them and realize the collaborative design of products through effective communication mechanisms is a problem that must be solved. The traditional PDM is mainly based on the two-layer structure of C/S, and also has a three-layer structure. DCOM or CORBA technology is generally adopted for the three layers, but these two technologies cannot meet the cross-platform environment requirements, making the traditional PDM Unable to work in a cross-platform heterogeneous environment.
1. 2 lack of user friendliness
Today's PDM is more complex, wider, and faster than ever. Many PDMs have their own unique interfaces and operations when implementing a new PDM system. Users should spend a lot of time learning to familiarize themselves with new software. time.
1. 3 The complexity of maintenance work
For traditional PDM, it is divided into client and server. When the enterprise needs change and the business logic or interface is changed, all clients that have installed the PDM system must be upgraded, which greatly increases the maintenance complexity of the PDM system.
2 Advantages of the Web-based PDM system
2. 1 friendly user interface
Developing client software with Web technology is more user-friendly. Simple and cheap web browsers allow more people in the enterprise to use the PDM system, making it easy for them to access the company's vast information base online.
2. 2 strong applicability
Web browsers exist on different platforms, but can provide the same interface look and feel.
2. 3 is more conducive to supply relations
On the one hand, it allows companies and suppliers to share strategic information and easily share key information. On the other hand, customers can implement product online configuration through the network and quickly complete customization;
2. 4 can form a virtual enterprise
Through the Web-based PDM system, companies with expertise can temporarily join together to form a virtual enterprise, using their respective expertise to do the same project.
Web-based PDM system framework
In the literatures 3 and 4, the Web-based PDM adopts a three-layer C/S structure, which consists of a client layer, a Web service layer, and a database service layer. Through the 3-layer architecture, the system obtains the independence of the business logic and improves the system. Scalability, with a simple user interface, support for a variety of network structures and heterogeneous platforms. In this paper, combined with the above literature, the system framework of Web-based PDM as shown in Figure 1 is proposed. The whole system is divided into four layers, namely user layer, application function layer, system service layer and data storage layer. The following will introduce each layer separately:
3. 1 user layer
Providing an interactive environment with the user is the entry point for the user to enter the system, and the web browser is a tool for interacting. The user layer is responsible for accepting the information provided by the server and can send feedback based on the information. The server creates information in the HTML language and sends it to the client. The client displays the text, image, and other information after being interpreted by the web browser.
3. 2 application function layer
A functional module consisting of a set of programs and interfaces that call PDM basic services, and can perform certain application functions, such as document management, component management, product structure management, project management, integration interface, and so on. On the one hand, it provides the user layer interface and PDM service functions upwards; on the other hand, it obtains the data services and other basic services provided by the system service layer.
3. 3 system service layer
Can be seen as a set of object models, mainly to complete the following functions: First, connect and manipulate the database downwards, this function is realized through the database interface; Second, provide data services and business logic services to the application layer through the internal interface; It provides an external interface to provide an interface to the data management system of the collaborative enterprise. The latter two functions are mainly implemented through a data service interface based on Webservice technology.
l) Database interface
The operation of the database is carried out through various database interfaces. The database interface provides various operations on the database. Many development tools support various data interfaces. In the development process, these interfaces only need to be added to the program, and the functions provided by them are called. There is no need to consider the underlying database.
2) Data interface service based on Webservice technology
The data service interface is divided into an internal interface and an external interface. The internal interface is used by the internal application layer of the enterprise, and the application system outside the enterprise cannot be accessed. The external interface is open to the enterprise external application system for development calls.
Traditional distributed technologies have consistency requirements for platforms. Webservice technology can overcome this platform constraint and implement cross-platform data interface services. The process of WebService implementation is shown in Figure 2. First, Enterprise A's developers use the WSDL description tool to wrap their own services into WebService external service interfaces. Next, publish the packaged service and its description to the WebService registry UDDI as needed for future reference. If another enterprise B's application wants to integrate with this enterprise application, it only needs to query the registry of the Web service through the UDDI API, obtain the description document of the WSDL of the other WebService, and then load the WSDL description document into itself. In the development platform, and generate the corresponding interface.
3. 4 data storage layer
The data storage layer generally consists of two types of servers, one is the database server, which is responsible for the maintenance and management of metadata, and the other is the file storage data warehouse, which is responsible for the storage and management of physical files.
Applications
4. 1 Demand Analysis
Kailing Group is a large-scale motorcycle brake manufacturer in China. It has a wide range of products and a wide range of sales. The main materials of the company have been electronically produced, and the product types have been planned, but there is no effective data. Management system, data management is increasing in difficulty. The main problems are: lack of centralized management of product data; lack of product management software to assist in the management of product categories; lack of effective coordination with collaborative companies or external subsidiaries.
In response to some of the above problems, the company will be provided with a Web-based product data management software, which can also meet the management of product categories and product configuration.
4. 2 system framework
The entire PDM system is divided into four layers, the user layer, the system application layer, the system service layer, and the data layer.
1) The user layer uses IE6. 0 as the browser;
2) The system application layer uses the VB.NET and C# programming languages ​​to write the functions of each module;
3) system service layer XML Web service encapsulation part of the business interface;
4) In the data layer, the database uses Sq1 Server 2000, the metadata is stored in the database, and the physical files are stored in the file server.
4. 3 Network environment
They are technical system network, financial system network and ERP management network. The technical system network and the financial system network are relatively independent, and a separate network needs to be established to ensure data security.
The technical system network and the financial system network are independent and connected to the ERP network through their respective gateways. In this way, the technical system network and the financial system network can access the resources of the ERP, but the ERP network needs to access the technical network or the financial network, and needs to be set through the gateway, as shown in FIG.
4. 4 system function
Mainly divided into classification management, document management, parts management, product model management, and supporting table management.
The classification management module function is to provide documents, parts, models, matching table types and attribute settings.
The document management module functions are: providing input, modification, deletion and version control management of electronic files; providing query function, supporting simple query and query by document attribute; providing browsing and copying of drawings.
The function of the component management module is to provide the establishment, modification, deletion and version control of the components; to provide the query function, to support simple query and query by component attributes, and to support the query of component usage;
The function of the product model management module is: providing the establishment, modification, and deletion of the model; providing the addition, deletion, modification, and definition of configurable node components on the model structure tree; providing the model view structure tree and each component component Information and its associated documentation;
The function of the matching table module is to provide a new matching table from the existing models by selecting configurable parts; provide the association between the matching table and the assembly drawing, fill in the special description, fill in the relevant attributes, and fill in the special parts description. Provide version control of the matching table, retain the historical version; provide query function, support simple query and query according to the related attributes of the matching table (supporting manufacturers, supporting models, supporting drawing numbers, company models, etc.).
4. 5 Interface Services
Data Interface Services: Provides internal and external interfaces, including: GetModelTree: Get the model structure; GetDocuments: Get the relevant documentation; GetObjectproperty: Get the object properties; Getparts: Get the component list; Get Part Trees: Get the component structure. GetPartPV: Get interfaces such as component properties. These interfaces can be published to the Internet via UDDI or other methods, and collaboration companies can integrate into their enterprise applications as needed.
to sum up
The Web-based PDM system is the trend of future product data management software development. The driving force behind this trend is the demand for economic globalization. With the further development and improvement of Web technologies, Web-based PDM systems will be more widely used and play an increasingly important role in the development of collaborative products for enterprises.
Portable Generators are useful when temporary or remote electric power is needed, but they can be hazardous. The primary hazards to avoid when using them are carbon monoxide poisoning, electric shock or electrocution, and fire.
We would like you to know that there are simple steps you can take to prevent the loss of life and property resulting from improper use of Portable GeneratorsTo Avoid Carbon Monoxide Hazards:
1. Always use generators outdoors, away from doors, windows and vents.
2. NEVER use generators in homes, garages, basements, crawl spaces, or other enclosed or partially enclosed areas, even with ventilation.
3. Follow manufacturer's instructions.
4. Install battery-operated or plug-in (with battery backup) carbon monoxide (CO) alarms in your home, following manufacturer's instructions.
5. Test CO alarms often and replace batteries when needed.
To Avoid Electrical Hazards:
1. Keep the generator dry. Operate on a dry surface under an open, canopy- like structure.
2. Dry your hands before touching the generator.
3. Plug appliances directly into generator or use a heavy-duty
outdoor- rated extension cord. Make sure the entire extension cord is
free of cuts or tears and the plug has all 3 prongs, especially a
grounding pin.
4. NEVER plug the generator into a wall outlet. This practice,
known as backfeeding, can cause an electrocution risk to utility workers
and others served by the same utility transformer.
5. If necessary to connect generator to house wiring to power
appliances, have a qualified electrician install appropriate equipment.
Or, your utility company may be able to install an appropriate transfer
switch.
To Avoid Fire Hazards:
1. Before refueling the generator, turn it off and let it cool. Fuel spilled on hot engine parts could ignite.
2. Always store fuel outside of living areas in properly labeled, non-glass containers.
3. Store fuel away from any fuel-burning appliance.
Portable Generators
Portable Generators, Portable Gasoline Generators, Generators Suppliers, Portable Electric Generators, Mini Portable Generators
Zhejiang Taizhou Wangye Power Co., Ltd , http://www.wyengine.com