Implementation of an ASP-oriented Distributed Collaborative Design Systemand its Applications in Pervasive Computing Environment

Linxuan ZHANG, Tianyuan XIAO, Ce LIANG

National CIMS Engineering Research Center

Department ofAutomation, Tsinghua University, Beijing 100084, China

E-mail. Cxzhang by edu cn

Abstract

With the progress of globalization, current productdesign in manufacturing enterprises demand distributed,heterogeneous, and real-time supporting environment;however, most of manufacturing enterprises in China,especially those small and medium enterprises, can notafford to buy the expensive software, hardware andservice for the special purpose. Collaborative design isthe most important task of all activities at the productdevelopment lifecycle under Networked Manufacturing(NM) and Application Service Provider (ASP) orientedsystem is an effective approach to NMplatforms. In thispaper, combined industrial requirements with our effortsin some research projects funded by the Hi-Tech R&DProgram of China and Beijing Municipal Sci-TechProgram, an ASP-oriented distributed collaborativedesign system namely Co-Design is proposed to supportremote collaboration among enterprises in a pervasivecomputing environment. Architecture of the system ispresented and some key techniques of collaborativedesign are researched Now the proposed Co-Designsystem has been implemented and used as ASP tools tohelp several small and medium enterprises to acceleratetheir product development and typical applicationexamples shows that substantial benefits can beachieved by reducing of collaboration expenditure,development cost and shortening time to market.

Keywords: Collaborative Design, Application ServiceProvider (ASP), Networked Manufacturing (NM),Pervasive Computing

1. Introduction

From the review of pervasive computing[i], its centralcontribution is to provide a support environment for our

developing application needs in the new informationeconomy era. In recent years, pervasive computingtechnologies and associated software are beingemployed to facilitate such applications as telemedicine,education, transportation, marketing, space endeavors,

crisis management, and military for all the time andeverywhere use. These applications demand automated,continual, and unobtrusive services and proactivereal-time collaborations among devices, software agentsand geographically distributed personnel in dynamicheterogeneous environments[2]. Though reportedcases[14] shows applications of pervasive computing inindustrial product design are quite not as much as thosein the above areas, it is also becoming an emergingtechnology to revolutionize traditional product designstyle, especially for manufacturing enterprises in currentinformation era.

With the progress of globalization, manufacturingenterprises in China have found what they are facing are

both opportunities and challenges almost at the same

time. Cooperation activities such as product design,process design, and outsourcing discussion, etc., amongeither domestic or oversea enterprises have becomemore and more than ever and demand distributed,heterogeneous, and real-time supporting environment.Obviously applications of pervasive computingtechnologies can enhance the desired environment tosome extent; however, they cannot meet the wholedemands perfectly, especially for those complicatedindustrial products. Some world-leading IT servicecompanies such as IBM, HP, EDS, etc., may say theycan provide excellent professional solutions to solvethese problems, but actually it is too expensive for mostof manufacturing enterprises in China, especially forthose small and medium enterprises, to buy associatedsoftware, hardware and service for the special purpose.

We propose to combine Application Service Provider(ASP) with Networked Manufacturing (VM), focusingon R&D of an ASP-oriented collaborative design system,to enable implementation of the desired environment tosupport collaborative and distributed product design in a

pervasive environment.The main purpose of NM is to carry out generalized

product manufacturing via the Internet/Intranet, i.e., toundertake tasks such as collaborative product design,product manufacturing and some other related activities,though various definitions of NM have appeared in

1-4244-0971-3/07/$25.00 ©)2007 IEEE.

these years. Design of a product is usually regarded asthe origin of its formation to a great extent. Therefore,undoubtedly, collaborative design can be regarded as themost important task of all NM activities at the wholelifecycle of product development. In order to achievecollaborative design under NM environment, manyattempts have been made by researchers from both ofuniversities and enterprises[ss]. ASP is a well acceptedpractical technique of these attempts and has become afashion of enterprise informationization both in Chinaand abroad.

ASP-oriented system has been proved to be a highlyeffective approach to NM platforms. Drawing lessonsfrom the idea of intensive management, ASP acts as aservice mode that the professional service companyprovides centralized management of costly high levelsoftware systems and their related technique supportsmeanwhile small and medium enterprises rent ASPservices to implement normal business management andto achieve high level informationization at an easy rate.This kind of service mode can lower the threshold ofhigh level informationization dramatically and hence ithas won the favor of enterprises, especially those whohave not enough money for hardware and softwareinvestments and lack professional IT engineers. InChina, about 99 percent of companies are small andmedium enterprises (whose production value is less than100 million Yuan and employees are less than 300), andthey create 40 percent of the whole production value ofall the companies[s]. Consequently we can foresee thatASP-oriented system will become a dominant directionof informationization development for small andmedium enterprises henceforward and in the meantimelarge amounts of small and medium enterprise users willprovide a huge latent market for the ASP techniquedevelopment.

Some large scale commercial collaborative designsupported systems such as PTC Windchill, EDSTeamCenter, Dassault Enovia, MatrixOne eMatrix, etc.,have been developed by world-leading companies.However, these systems seem to share the followingcharacter flaws:1) They are designed mainly for large scale enterprise.

They seem to be perfect by providing all kinds ofexcellent functions for enterprises, but they are tooexpensive to suit small and medium enterprise.

2) The integration with CAD systems should befurther enhanced. Usually a system offers seamlessintegration only with CAD system(s) from the samecompany as itself but not from other companies.

On the other hand, some small support tools whichrealize collaborative design through terminal service,such as PC Anywhere, Exceed, VNC, etc., have thefollowing shortcomings:1) Sharing only one session and supporting only one

user to login at a certain time.2) Not supporting three dimensional solid graphics.3) High request for bandwidth to insure network

speed.4) Supporting only one operating system at client, not

allowing multi-operating systems.5) Due to C/S structure, software must be installed at

client.6) Mechanism of authority control is not flexible.

Currently, according to the need of domesticinformationization construction, several ASP-orientedcollaborative design systems suitable for small andmedium enterprises have been developed by researchersin China[5s]. In this paper, combined with our efforts insome research projects funded by the Hi-Tech R&DProgram of China and Beijing Municipal Sci-TechProgram, an ASP-oriented distributed collaborativedesign system based on web is introduced. Itsframework is presented and some key techniques ofsystem implementation and their solutions areresearched. And then practice of the system isdescribed.

2. System Architecture

2.lArchitecture of General ASP System

The architecture of a general ASP system can beillustrated by a three-level structure shown as in Figure1, i.e., Web Browser, Web Server and ApplicationServer. Where, service management and schedulingsystem is constructed between Web Server andApplication Server.

Application Server

Figure 1 Architecture of general ASP system

Features of ASP system can be summarized asfollows[s]:* Application services can be provided to clients by

renting. It means no need of large investment onequipments, software and human resource, and,hence, reduction of investment risk.

* Centralized management is employed to applicationservices. In general, ASP services are managed at acenter, and clients access specified application viathe Internet.

* Diversity of requirements and application services.As the most prominent feature, it means that

diversity of consumers creates diversity ofrequirements, hence, diversity of application styles,shared resources, commercial manner, as well ascomplexity of security and charging.

2.2 Architecture of the Proposed Co-DesignSystem

Combining industrial requirements with our efforts insome research projects, we have developed anASP-oriented collaborative design system, namelyCo-Design. The proposed system supportdistributed real-time product design via theInternet/Intranet. Its aim is to build a virtualComputer Supported Cooperative Work (CSCW)environment, and makes it possible that we candesign a product at the same time and fromdifferent locations. Furthermore, it providesfriendly interfaces with some resource libraries,such as mechanical component library, electroniccomponent library, etc., to help engineers to designproduct more efficiently by utilizing these

resources. Real-time collaborated design means thedesigner in collaborative design environment canperceive others' action in time. This collaborativemethod makes the design task be explored amongthe designers who are in different places and canmeet the needs of collaborative product designamong enterprises.

Figure 2 shows the general architecture of theproposed Co-Design system. The system iscomposed of four levels of functional modules: threefundamental levels, i.e., service-portal level,service-enable level and administrative level, and acommon resource level. Where, service-enable level andadministrative level form the core of the ASP-basedistributed collaborative design system meanwhile theother two levels, i.e., service-portal level and resourcelevel, are optional modules for NM-orientedinformationization according to the needs of enterprises.However, if all of the above four levels are joinedtogether, an integrated NM-oriented distributedcollaborative ASP platform can be formed. Functionsof the four levels are summarized in the following.

Common Management Suite for Networked Manufacturing Level C

ASP-Oriented Collaborative Design System

Co-Interactive Browsing &Environment Review

Co-Workshop Security

Object FileUpload/Download

Image Partial-Renewal& Transfer

Mechanical Electronic Software ManufacturingComponent Lib Component Lib Resourse Lib Resourse Lib

Figure 2 Architecture of Co-Design system

1) Service-portal LevelIt is a portal administration module which provides

universal application- independent service portal for theNM- oriented ASP platform. Main functions of theportal are as follow: providing entrance ofsingle-sign-on authentication; providing entrance ofintegrated navigation for various applications andservices; and supporting user-defined webpage set-up.

2) Service-enable LevelIt is a collection of core modules which make

collaborative design services available for end users.

These modules, mainly used by commonusers, are arranged to provide a virtualworkspace for distributed engineerscollaborative design activities. The fivemodules are listed as follows:* Collaborative Interactive Environment* Browsing & Review* Object File Upload/Download* Collaborative Workshop Security* Image Partial-Renewal & Transfer

Co-Designinteractiveto fulfillfunctional

3) Administrative LevelIt is a collection of core modules which make

Co-Design administrations available for two kinds ofadministrators. One is for collaborative team leaders tomanage design workspace, usufruct, resources, etc.Another is for system administrators to manage andmaintain the system itself. The five functional modulesare listed as follows:* Usufruct Management* Collaborative Workshop Management* Collaborative ServiceInfo Management* Charge Statistics* System Log Management

4) Resource LibrariesIt is a collection of common resource libraries which

facilitate collaborative design activities by utilizingthese resources, such as selecting standardmechanical parts and/or electronic elements fromlibraries directly. Where, these mechanical partsand electronic elements can be stored as specified

parametric templates in libraries and beinstantiated to get actual form and dimensions atproduct design. The four libraries are listed as follows:* Mechanical Component Library* Electronic Component Library* Software Resource Library* Manufacturing Resource Library

3. System Implementation

3.1 Technical Architecture of the System

From technical viewpoint of implementation, theproposed Co-Design System is constructed by fourlayers structure based on J2EE: web explorer, webserver, LAN control agent and application server. Thetechnical architecture is shown as figure 3.

The Co-Design system can running on many kinds ofoperation systems, such as windows 2000/2003,Windows XP, Unix, Linux. And it hasn't any additionaldemand to client except web explorer.

Figure 3 Technical Architecture of the Co-Design system

3.2 Synchronization Mechanism of DistributedCollaboration

During the process of collaborative design, it needscooperation among the geographically distributeddesigners. So we must have a concurrent controlmechanism to guarantee that all users develop their goalin special orders otherwise there will be impossible toachieve their common goal because of the inefficiency.

During the implementation of the collaborative designsystem, we adopt the method of token control to achieveour concurrent control function.

3.3 Autoadaptive Image Compression andTransferring

The geographically distributed real-timecollaborative design system can run not only in the

situation of the Internet but also in the Intranet. Becauseof restriction of the unbalance of network developmentin our country, we adopt two kinds of imagecompression method, i.e., JPG-based method andPNG-based method respectively, to implement thesystem in order to adapt to the different networksituations. The compression method, JPG format orPNG format, is adopted autoadaptively according tobandwidth of the Intranet/Internet. Only 512Kbandwidth is enough to implement the real-timesynchronization in interactive collaborative design.

4. Applications of the Co-Design System

The proposed system Co-Design can be used in apervasive computing like environment. No matter wherethe user is, and no matter when the user want to use thecollaborative design support tool, he needs only anordinary computer, either a desktop or a laptop, to loginthe Co-Design system via Internet browser such asInternet Explorer, Netscape Communicator, MozillaFirefox, etc., to carry on distributed collaborative design.No need to install any special software or applicationtools, he can use the Co-Design system if only he canaccess the Internet. By utilizing the platform, top levelsoftware/hardware, professional services and technicalsupport can be obtained by enterprises specificallywithout professional IT engineers and out of funds. Thiskind of ASP mode makes it quite easy, especially, forthe small and medium enterprises, to achieve high levelinformationization.Now the proposed Co-Design system has been

applied to several networked manufacturing platform insome industrial informationization projects, especially

in Beijing area. For example, it has been used as anapplication service tool on the NetworkedManufacturing Platform of the Beijing Electronic Zone(Beijing Electronic Zone Incubator Co., Ltd., URL.http)//mapp.bez.com.cn/eas -ecm-yiew/displayegm/2)and used as collaborative product development systemon the Networked Manufacturing Platform of BeineiIncubator (Beijing Beinei Manufacturing High-techIncubator Co., Ltd., URL. ).Figure 4 shows architecture of Beinei Incubatornetwork-based Manufacturing Platform in which Co-Designsystem acts as a collaborative product developmentsystem. Figure 5 shows an example of productcollaborative design via Beinei Platform.

The effects of the system application can besummarized as follows:* Small and Medium enterprises can use the big

advanced manufacturing equipments and softwareand realize the informationization withoutexpensive expenditure that is used to constructinfrastructure of network and buy equipments andsoftware.

* Searching for collaborators in wide range makes thecollaborative designing and developing easy andeffective, which upgrades the development abilityof small and medium enterprises.

* Typical applications of the system were more than16 enterprises, and were spread more than 200enterprises, which have produced substantial socialand economic benefits by reducing of collaborationexpenditure, development cost and shortening timeto market.

Figure 4 Architecture of Beinei Incubator network-based Manufacturing Platform

Figure 5 Industrial application example of Beinei Incubator NM Platform

5. Conclusions

ASP-oriented system is a highly effective approachto NM platforns. In this paper, an ASP-orienteddistributed collaborative design system is proposed tosupport remote collaboration in a pervasive computingenvironment. Architecture of the system is presentedand some key techniques of system implementation are

researched. Now the system has been implemented andused as ASP tools to help several small and mediumenterprises to accelerate their product development andtypical application examples shows it can bringsubstantial benefits.

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