Modeling analysis and design of the hottest flexib

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Modeling analysis and design of flexible PLM system

I. Introduction

product lifecycle management involves the information and process in the whole life cycle of products from demand, planning, design, production, sales, operation, use, maintenance to recycling and disposal. It is both a technology and a manufacturing concept. It is of great significance to support collaborative R & D, management, distribution and use of product definition information related to products, and to research and develop a product lifecycle management system

with the deepening of management globalization and the development of network technology, developing a platform independent, distributed, object-oriented, web-based and highly adaptive software system is the development direction of PLM

FSS flexible software system refers to an application software system that can meet and adapt to the changing needs of users within a certain range. When the use environment and user needs change, it can meet the new needs of users without modification or with a little modification. These characteristics coincide with the requirements of PLM system. Therefore, the development of PLM system based on flexible software theory and technology has broad prospects

based on the theory of software flexibility, this paper analyzes and designs the flexible PLM system based on workflow

2. Architecture of flexible software

according to the definition of flexible software system, it is not difficult for us to figure out the requirements of this architecture. It should be object-oriented, component supported and hierarchical framework management. The hierarchical logic model of this framework is divided into: environment layer, environment layer, environment Abstract Layer, business abstract layer, application layer, presentation layer, etc. In these levels, the upper level is the lower level customer, and the lower level is the upper level service provider, as shown in Figure 1

from the process in Figure 1, the main features of flexible software architecture (FSSA) are:

(1) the components of FSSA are objects, components and frameworks

(2) FSSA is a hierarchical architecture, and different levels are the functional abstractions of the whole system

(3) FSSA is a semi hierarchical architecture. Except that the application layer can realize cross layer interaction, other layers can only interact with adjacent layers, and each layer can only get services from the lower layer and provide services to the upper layer

(4) message sending mechanism and BS mode are adopted for the interaction mechanism at the level

(5) the internal structure of each floor is based on the frame structure, guided by objects and constructed by components

(6) adopt object-oriented technology from all angles. Generally, a software can be logically divided into three layers, namely, presentation layer, business logic layer and data layer. In FSSA, the business logic layer is divided into business abstraction layer, business layer and application layer. The data layer becomes a part of the environment layer and is encapsulated by the environment abstraction layer. This multi-layer structure mode breaks through the limitations of two-layer mode and three-layer mode, and has good scalability

the flexible software developed according to FSSA should have the following characteristics:

(1) fast modeling

fssa has made an in-depth analysis of the business field and created an architecture with flexible business field. Therefore, the requirements of the user's business field can easily match the FSSA architecture, coordinate the UML and Petri modeling features, and quickly complete the software modeling

(2) fast dynamic configurability

the flexible software system control platform (fsscp) is introduced into FSSA. Both users and developers can complete the adjustment and configuration operations, shortening the time required for the adaptation process of flexible software

(3) reconfigurability

fssa adopts the component construction method with multi-layer framework structure as the core to develop software, making it easy for developers to change the software function and structure

(4) integrability

fssa adopts the environment abstraction layer, which makes it possible to combine software in different operating and development environments by 5.18%

note: Lu low level user Hu high level user Du developing level user

III. flexible PLM system architecture

plm has been expanded on the basis of PDM, considering the whole life cycle of the product. Based on the traditional PLM architecture and the concept of Figure 1 Software flexible architecture, this paper proposes a product lifecycle model based on STEP standard and workflow technology. The whole framework is mainly divided into four layers: modeling layer, support layer, interface layer and application layer. As shown in Figure 2, each layer corresponds to the corresponding layer in Figure 1 in terms of functional implementation

application layer: corresponding to the application layer in Figure 1, including CAX system, office automation system, SCM (Supply Chain Management), CRM (Customer Relationship Management), ERP, etc. Using CORBA technology, integrated into a process management system, it is convenient to interoperate between different subsystems

interface layer: corresponding to the business layer in Figure 1, including the integration framework in the subsystem of the application layer. The implementation of these frameworks encapsulates and integrates existing application systems, supports the definition, development and management within each subsystem, and realizes the integration of information processes between different subsystems

support layer: corresponding to the business abstraction layer in Figure 1. What is involved here is the data management of product information. It is mainly completed with the help of the enabler of PDM (Product Data Management). Realize the functions of DM (document management), PM (Project Management), pcm/psm (product control/structure management) and Sm (software system management). PM can also become another part of the support layer as an independent individual. Here, it mainly reflects the seamless management of PDM in product data and becomes a part of PDM enabler. In addition, a certain amount of application development tools are provided in this layer

modeling layer: model analysis and design of the overall system framework and data flow. UML language is used here. The data structure of the data logic layer is expressed in step express language, and the data physical layer uses XML as the intermediate file exchange format

workflow management platform plays the role of flexible central hub in the whole data management, and CORBA and other integration technologies are the concrete granulation and application of the environment abstraction layer. They are the foundation of the above four layers

Figure 2 flexible PLM system architecture diagram

IV. technical support

1. J2EE technology

j2ee (Java 2 platform, Enterprise Edition) can meet the requirements of Internet for distribution, openness and platform independence in terms of Intelligent Web services, support the development and design of four tier architecture software, and fully support XML technology that is platform and language independent and has great advantages in data exchange, display, distributed computing, etc, In the development of flexible PLM, J2EE component technology will be fully used to build a PLM system with multi-layer BS mode

j2ee not only consolidates the advantages of Java 2 Platform Standard Edition, but also has the following advantages:

(1) it provides a multi-layer distributed framework structure

this structure supports distributed computing and realizes loose coupling between server applications and clients

(2) support container component technology

the container transparently provides services such as transaction management, security check, resource buffer and bottom overall view, simplifying component development technology

(3) EJB Technology

provides a framework for developing and implementing distributed business logic to ensure the stability and scalability of the system

2. XML technology

aiming at the dynamic, real-time and interoperability of PLM system, XML technology is introduced to process relevant data on the basis of J2EE

xml (Extensible Markup Language) has become the standard of data exchange, greatly surpassing HTML and realizing cross platform data exchange and operation. It has the characteristics of openness, rich expression effect, easy to read, convenient network transmission and so on. It has obvious advantages in data description and distributed computing

plm manages all relevant information and processes in the whole life cycle of the product. Its function module must contain a large number of processing processes for describing, displaying and accessing these information. Using XML technology to process these information can maximize the stock price rise of Suning in the next day without any suspense, and realize the utilization and sharing of information, which is an inevitable choice in development

3. Software agent technology, component technology and soft bus integration technology

agent technology can support high-level component interoperability for software systems in a separate state. At the same time, it can provide intelligent services for the application components in the PLM system in the multi-layer BS mode. It has a dynamic execution mode and can directly interact with the service source without network transmission

component is a well-defined software module designed in accordance with the specifications. It has a consistent external interface and has good support in solving the standardization of object interface and improving software reusability and system integration

in the design of flexible PLM system, the design scheme based on workflow integration is adopted. Workflow plays the role of "bus" in the operation of the system, that is, soft bus integration technology. This makes the integrated application software and system without any restrictions, and supports the process integration of concurrent engineering to realize the optimal combination of enterprise production and management

therefore, agent technology, component technology and soft bus integration technology are the key technologies to solve the PLM flexibility problem

4. Modeling technology

in the development of PLM system using software component technology and bus integration technology, it is necessary to clearly express the software code in physical files, binary files, executable files, executable files and library files, and further determine how to deploy the software code to achieve the best effect, which requires modeling components. Here, consider using UML

uml (Unified Modeling Language) can provide modeling and visual support for every step of software development, from requirements analysis to technical specifications, to structural design and configuration. It not only provides a standardized marking method for the basic building blocks in software system modeling, but also provides an expression method for the complex relationships in the basic building blocks

on the basis of expressing components in UML model diagrams, components in component diagrams can be further developed. J2EE applications provide all the different components that make up enterprise applications, including web components and EJB components. UML provides an extension mechanism of the category template file. Applications can be embodied into two types of templates, namely:

"webcomponent": for web components composed of servlets and JSPS

ejbcomponent: used for enterprise JavaBean (EJB) components

jar (Java archive file) files contained in Java programs and EJB jar files can be expressed as packages with javaarchivefile and ejbjarfile templating when heated continuously or intermittently; The class file component of Java is templated to javaclassfile; The Web Archive file containing rvlets and HTML packages is represented as a templated package of webarchivefile; With the help of these templated component structures, it will be easy to express the software hierarchy. Figure 3 is the description diagram of web components in the component diagram, and other description forms are omitted

the whole system is based on workflow technology. For the modeling and verification of workflow logic, it is suggested to adopt the combination of extended UML mechanism and Petri. The graphical process model is established with the help of UML extension mechanism, and its rationality is verified from the perspective of mathematical theory with the help of Petri s. The whole process is not described here

v. summarize that

product life cycle management is the key technology of enterprise informatization, and design a reasonable and effective PLM system

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