03 an internet enabled integrated system for codesign and concurrent engineering

8/3/2019 03 an Internet Enabled Integrated System for Codesign and Concurrent Engineering

1/17

An Internet-enabled integrated system for co-designand concurrent engineering

W.D. Lia,*, J.Y.H. Fuhb, Y.S. Wongb

aSingapore Institute of Manufacturing Technology, 71 Nanyang Drive, Singapore 638075, Singaporeb Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576, Singapore

Received 25 June 2003; accepted 25 October 2003

Available online 24 May 2004

Abstract

In order to facilitate the product design and realisation processes, in this paper, an Internet-enabled system has been developed

to support collaborative and concurrent engineering design by seamlessly integrating three functional modules, i.e., co-design,

Web-based visualisation and manufacturing analysis, based on some state-of-the-art Java and Web technologies. In the co-

design module, designers are equipped with co-modelling and co-modification facilities to carry out a design task collabora-

tively. The Web-based visualisation module provides a portal for users, who are not involved in the co-modelling process

directly, to view and analyse a design part conveniently. Services in the manufacturing analysis module can be invoked by users

dynamically to evaluate and optimise the manufacturing costs and the manufacturability of a design part so as to implement the

concurrent engineering methodology during a co-design process. This system can be used for a design team geographicallydistributed to organise a 3D collaborative and concurrent engineering design effectively, and the proposed distributed and

integration architectures enable the system to be generic, open and scalable.

# 2004 Elsevier B.V. All rights reserved.

Keywords: Co-design; Concurrent engineering; Web-based visualisation

1. Introduction

Manufacturing corporations have become more

product-oriented, aiming at decreased lead times fromdesign to manufacturing, minimal work-in-process,

just-in-time flow of materials, and high efficiency

and flexibility of manufacturing capacity utilisation.

Recently, many philosophies have come into existence

to facilitate the product design and realisation pro-

cesses. Concurrent engineering (CE) is a systematic

approach to integrate the design of products with

related manufacturing processes using some software

packages and computing techniques in a computer

environment [1]. Within CE, a designer can considerand evaluate the downstream manufacturing processes

of the product life-cycle in the initial design phase.

Co-design is another increasingly important philoso-

phy used in modern manufacturing corporations to

collocate a multidisciplinary design team to carry out a

complex design task through effective communication

and collaboration. CE and co-design are complemen-

tary in functions since the former emphases a verti-

cally seamless linkage between the upstream design

and the downstream manufacturing processes through

Computers in Industry 55 (2004) 87103

* Corresponding author. Tel.: 65-6793-8354;

fax: 65-6791-6377.

E-mail address: [email protected] (W.D. Li).

0166-3615/$ see front matter # 2004 Elsevier B.V. All rights reserved.

doi:10.1016/j.compind.2003.10.010


2/17

the creation of intelligent strategies for effective infor-

mation interchange, while the latter focuses more

on the horizontally interpersonal aspects of group

work in the upstream design phases. With the trendfor global competition and the rapid advances of the

Internet technologies, both of them are moving

towards supporting distributed applications, in which

geographically dispersed users, systems and resources

can be integrated in an Internet/Intranet environment

beyond the traditional boundaries of physical and time

zones.

In this paper, an Internet-based integrated system

has been developed to support interrelated activities

and share domain knowledge between designers and

systems through integrating CE and collaborative

design functions. This system consists of three pri-

mary modules: (1) a co-design module to enable

designers to fulfill product design collaboratively;

(2) a Web-based visualisation module to support

product preview and evaluation of design parts; and

(3) a manufacturing analysis module for designers to

conduct CE methodology through invoking some

distributed services. The system infrastructure and

its distributed mechanism are built based on some

Java and Web technologies, and high-performance

communications among modules are maintained

based on an event-based mechanism. The main advan-tages of this work include: (1) a convenient and

flexible platform has been setup for users to carry

out a co-design activity, with a scenario similar to the

actual teamwork situation; and (2) a generic and

scalable distributed mechanism has been proposed

to integrate different functional modules in the system

effectively to support CE, Web portal-based visualisa-

tion and co-design.

2. Recently related work

2.1. Co-design

The research and developments in co-design are

active and a number of software tools and methodol-

ogies have been developed in this area. The appeared

work can be generally categorised into two types from

the perspectives of collaborative strategies and func-

tions: (1) visualisation tools to assist co-design, and

(2) co-modelling tools to implement co-design.

The work in the first category is primarily used to

support visualisation, annotation and inspection of

design models in a Web or a CAD environment.

Commercial systems include AutovueTM

[2], Con-ceptWorksTM [3], eDrawingsTM [4], StreamlineTM

[5], etc. The Web-based systems are light-weight,

easy-deployed and platform-independent, and they

can facilitate an on-line team to take on high-level

product review, customer survey for new products and

conceptual design. Java Applet and MS ActiveX

technologies are widely used for developing the visua-

lisation clients, while some services written in Java

Servlet or MS COM/DCOM technologies are

deployed in the server side to provide support and

system maintenance [68]. In order to deliver and

manipulate interactive 3D objects effectively in the

Web, some concise 3D formats for Web applications,

such as VRML, X3D and MPEG-4, have been

launched to represent the geometry of 3D CAD mod-

els as visualisation-used triangular meshes and trim-

ming lines [9]. Most of the current CAD systems are

equipped with an export function to convert a native

model to a concise 3D model for Web applications

(e.g., VRML). However, during the conversion pro-

cess, the information for the high-level design fea-

tures, which are quite important in CAD systems to

encapsulate design intents, is lost. Due to this limita-tion, most of the visualisation systems can only pro-

vide viewing and mark-up functions, and they cannot

effectively support some on-line manipulation opera-

tions on features such as highlighting or hiding a

feature and its properties in a design part.

Real co-design with co-modelling functions can be

supported by the second category, and several popular

systems are Alibre DesignTM [10], OneSpaceTM [11]

and CollabCADTM [12]. Co-modelling systems

usually consist of four kinds of componentsteam

management, distributed part and assembly modeller,repository and messaging. In the team management

component, collaborative mechanism and team organ-

ism principles are specified. The distributed part and

assembly modeller is used to establish a workspace to

effectively share and distribute detailed design models

among a working team. The repository can store and

manage design parts and related information. The

messaging component can support several popular

messaging services such chatting, discussion forum

and whiteboard among designers participating in a

88 W.D. Li et al. / Computers in Industry 55 (2004) 87103


3/17

co-design community. Among these components, the

distributed modeller is crucial and a lot of research has

been conducted. Two typical mechanisms have been

developed and their characteristics are compared in

Table 1. The second mechanism, i.e., manipulationclient modelling workspace, can manage design

models centrally to ensure the consistency of distrib-

uted modelling data effectively. Such mechanism can

be used as an application service provider (ASP)

business model and deployed in small and midrange

enterprises since the distributed modelling services can

be rented out and much initial investment cost can be

saved. For above co-modelling systems, a significant

problem is that the communication efficiency is still

quite far from satisfactory if large-size part or assembly

models are designed collaboratively. In order toaddress this problem, some works have appeared

recently to simplify geometric entities of distributed

feature-based models to accelerate the communication

[1316].

Due to the simplified mesh-based visualisation

model and the original modelling data being lost or

very difficult to recover, the visualisation tools sur-

veyed in the first category can only serve as support

tools to co-design, and simultaneous co-creation and

co-modification operations for detailed design cannot

be supported effectively. For the co-modelling tools

surveyed in the second category, there is much diffi-

culty to install, deploy and maintain them compared to

the Web-based visualisation systems. Therefore, it is

imperative to integrate these two kinds of tools in anentire system to provide Web-based visualisation and

co-design facilities simultaneously so as to facilitate

the different levels of collaborative activities and meet

the various requirements of users.

2.2. Distributed CE

It is becoming increasingly important to effectively

implement the CE methodology in a distributed and

co-design system. Recently appeared research work in

this category is summarised in Table 2. Three compet-ing technologies, i.e., MS COM/DCOM, CORBA and

J2EE, are the significant middle-ware technologies

adopted for establishing the communication infra-

structures of distributed CE systems [1722]. Liu

[17] proposed a MS COM/DCOM interface-based

framework to wrap and expose API functions of

CAD kernels/systems and process planning modules

for remote invocations. The common core interface

was proposed to encapsulate specific feature functions

of different CAD kernels/systems to provide a generic

Table 1

Two system architectures for co-design with distribute co-modelling functions

Mechanisms Functional descriptions Illustrative diagrams R & D examples

Modelling client

communication server

* Clients are equipped with

whole CAD systems and some

communication facilitators

Nam and Wright [31]; IX

DesignTM [32]; CollabCADTM [12];

Pahng et al. [33]

* A server plays as an information

agent and exchanger to broadcast

CAD files and commands

generated by a client to other

clients

Manipulation client

modelling workspace

* The data structures in clients

are light-weighed and they

primarily support visualisation

and manipulation functions

OneSpaceTM [11]; van den Berg

et al. [34]; Alibre DesignTM [10];

Li et al. [15]; Li et al.,

in press [16]

* The main modelling activities are

carried out in a common workspace

in the server side

W.D. Li et al. / Computers in Industry 55 (2004) 87103 89


4/17

and neutral application layer of various CAD kernels/

systems according to some international standards for

features such as STEP. In Jacquel and Salmons

system [23], features from an ACIS modelling kernel

are wrapped as agents for remote design and manu-

facturing analysis. Considering the complexity andvariation of features, the programming for wrapping

feature-based API functions of various CAD systems

as generic interfaces in a distributed system is quite

huge and the add-on wrapping structures make the

system quite heavy. Gerhard et al. [19] proposed an

event-based and agential framework to communicate

design and manufacturing information through agent

channels based on the Java Remote Method Invocation

(RMI) technology, and manufacturing analysis func-

tions are enveloped as services to support the estab-

lishment of an open and plug-in environment.Compared to the discussed former infrastructure,

the event-based mechanism can provide a more flex-

ible and lighter-weight working manner for commu-

nication and collaboration.

3. System framework and functional modules

In order to support a co-design activity with the CE

methodology, an integrated and Internet-based system

has been established to consist of three functional

modulesa co-design module for organising distrib-

uted and co-modelling design activities, a Web-based

visualisation module to facilitate product review, and a

module for downstream manufacturing analysis to

enable CE design. The entire system structure isshown in Fig. 1. Some functional details of the mod-

ules are given in the following.

3.1. Co-design module

A co-design module has been established to support

simultaneous, co-modelling activities of designing

parts. It is based on the Java RMI mechanism and

consists of a collaborative server and clients. In the

collaborative server, a look-up service has been

designed to provide a naming mechanism to manageclients and manufacturing analysis services dispersed

in the integrated system. The collaborative server can

dynamically generate working sessions based on a

Java RMI object factory mechanism, and provides

references to these sessions for clients to request

and manipulate. A working session maintained by a

session manager is to provide a common working

space for designers to participate in a collaborative

design community to share and manipulate co-design

models. Each session is associated with a feature-based

Table 2

Related work of distributed concurrent engineering for design and manufacturing

R & D work Key characteristics

Liu [17] A generic component framework for distributed feature-based design and process planning

Chen and Liang [18] A system integrating and sharing engineering information to support CE activities such as domain

investigation, functional requirement analysis, and system design and modelling

Jacquel and Salmon [23] An agent system supporting feature-based design and manufacturability evaluation

Shen et al. [35] A MetaMorph agent architecture for supporting distributed design and manufacturing activities

Zhao et al. [36] A system for product information exchange and sharing among distributed CAD/CAM users with

different platforms

Sung [37] A CyberCut system integrating product design and process planning, including several modules:

(1) a Web-based design tool; (2) a new geometric representation for information exchange between

the design and process planning modules, and (3) an automated process planning system

Sun et al. [38] An agent architecture integrating design, manufacturability analysis, process planning and scheduling

Nidamarthi et al. [39] Designers upload and download their CAD files in a server for sharing and exchanging based on VRML

Cheng et al. [20] A Web-based design and manufacturing support system with seven modules: electronic catalogue, intelligent

selection, mounting details, sealing devices, lubrication, manufacturing database, and design moduleHuang [40] A Web-based system to collaborative product design review

Kong et al. [21] An Internet-based collaborative system for a press-die design process for automobile manufacturers

Chan et al. [22] An integrated system to support an agile manufacturing based on agent and CORBA technologies

Zhou et al. [41] An Internet-based system for designers to look for and retrieve distributive design knowledge,

which is represented according to STEP standards and an ANN is used for knowledge search engine



5/17

modelling system developed based on a solid model-

ling kernel, i.e., Open CASCADE [24]. Through a Java

wrapping mechanismJava Native Interface (JNI), the

modelling kernel written using C can be linked

with the Java-based communication facilities through a

shared library, and the native API functions of the

kernel can be invoked and manipulated by Java appli-

cations. Each client is a Java application-based userinterface. It can support designers to input feature

parameters for creating a part in the server side,

visualise the part dispatched from the server, select

entities in a feature for local operations, and manip-

ulate the part such as queried of dimensions and

distance between entities. The Open CASCADE pro-

vides a function to convert its proprietary design

models to VRML models and can pass them to a

Java3D-based VRML browser in a Web-based visua-

lisation module for display and manipulation. The

main functions and components in this module are

shown in Fig. 2.

3.2. Web-based visualisation module

Visualisation of design models over the Web is one

of the effective means to assist co-design. Based on it,

design models can be dynamically published in a Webenvironment and conveniently accessed by remotely

distributed group of people from the management,

marketing, maintenance and customers for efficient

design collaboration, design process monitoring or

product preview. A Web-based visualisation module

has been developed based on the Java Servlet, Applet

and Java3D technologies to provide visualisation-

based operations and some collaborative functions

such as chatting and messaging. This module consists

of a Tomcat Web server, a Java3D-based Applet client,

Fig. 1. Three functional modules in the integrated system.



6/17

communication services based on the Java Servlet

mechanism in the Web server side to exchange infor-

mation between this Web server and one of the Applet

client, the collaborative server in the co-design mod-

ule, and the analysis services in the manufacturing

analysis module. In the Java3D-based Applet client, a

VRML model generated in the above co-design mod-ule can be browsed and manipulated. The main func-

tions and components of this module are shown in

Fig. 3.

3.3. Manufacturability analysis/process planning

evaluation module

Three previously developed manufacturability ana-

lysis/process planning evaluation systems can be inte-

grated in the system to support the CE design. These

systems include a manufacturing feature recogniser[25,26], a computer-aided process planner (CAPP)

[27] and a manufacturability analyser [28]. The man-

ufacturing feature recogniser can be used to interpret a

design part in terms of STEP-based manufacturing

features to facilitate downstream machining and eva-

luation. With the CAPP, the activities of selecting

machining resources, determining set-up plans, and

sequencing machining operations can be considered

simultaneously so as to achieve the globally lowest

machining cost according to a combined evaluation

criterion of minimising machining costs, cutting tool

costs, machine changes, and tool and set-up changes.

The manufacturability analyser can be used to eval-

uate the feasibility of machining a design part from the

perspectives of the machining volumes and elements

such as position faces for machining tools and tool

approach directions (TADs).Presently, the CAPP service with four alternative

methodsGenetic Algorithm, Simulated Annealing,

Tabu Search and hybrid Genetic Algorithm and Simu-

lated Annealing, has been integrated in the system [27].

The other two services are under the system integration

process. The cost of a process plan can be computed

in Table 3. In the co-design and visualisation modules,

Fig. 2. The functions and components in the co-design module.

Table 3

The machining cost for a process plan in the CAPP service

Variables Descriptions

TMC Total Machine Costof a process plan

TTC TotalTool Costof aprocessplan

TSC Total Set-upCost of a process plan

TMCC Total Machine ChangeCostof a process plan

TTCC Total ToolChangeCostof a process plan

APC AdditionalPenaltyCostof violating constraints in

a process plan

TWC Total WeightedCostof a process plan

TWC w1 TMC w2 TTC w3 TSCw4 TMCC

w5 TTCCw6 APC where w1 w6 are the weights.



7/17

the CAPP service, which is managed in their individual

look-up services, can be invoked for on-line evaluation

of a designed or viewed part.In the collaborative design module, a manipulation

client modelling workspace scenario is used to

facilitate central provision and maintenance of infor-

mation and services [16]. Two representations, thin

in the client side and strong in the collaborative

server side, respectively, have been proposed to

enhance the performance of the system effectively.

A thin face-based representation is established in the

client side to support the interactive visualisation and

some manipulation functions (selection, transforma-

tion, changing visualisation properties of displayedparts, etc.). In the collaborative server side, a strong

representation with features and part information is

set-up and maintained to provide primary feature-

based modelling functions. The collaborative server

provides an export function to convert an Open CAS-

CADE proprietary model to a VRML model for

visualisation. However, the primary geometric data

in a VRML model are triangular patches and boundary

trimming lines between faces, and the information for

the high-level features can not be preserved. In order

to organise the visualisation data as a feature-based

format to support some feature-based manipulations in

the Web-based visualisation module, such as high-lighting or hiding a feature in a part, dynamically

retrieving some important parameters and attributes of

a feature, or evaluating the creation history of the part,

a new visualisation format based on features and

VRML has been designed. In this visualisation format,

the information of each feature is organised as two

partsa set of the creation parameters retrieved dur-

ing the creation process of the feature, and a VRML

patch converted from the B-Rep of the feature. This

representation is generated and maintained by the

collaborative server in the co-design module.The distributed and collaborative mechanisms in

the system are described in the following section.

4. Distributed and collaborative mechanisms

4.1. Event-based mechanism for distributed objects

An event-based mechanism based on a multiple-

layer inheritance structure is used to wrap the

Fig. 3. The functions and components in the Web-based visualisation module.



8/17

exchanged information in a structural and extensible

way to take advantages of object-oriented concept.

According to the Java specifications, in order to com-

municate via the network, the defined events should beserialisable. In the first layer, an upper class for

events, which inherits the serialisable class of the

Java language, is defined and its sub-classes in the

other two layers are automatically seriablisable.

Meanwhile, the upper class provides a unified event

variable sent or received by the remote methods

declared in the remote interfaces of the distributed

environment so as to simplify the system structure.

The event classes in the second layer extend the

upper event class and are classified as the following

three types mainly:

(1) Input event in a client. This event wraps the input

information in a client and is dispatched to a

server for modelling or a service for analysis.

(2) Object event for a design part. This event wraps

the design part generated from the collaborative

server and sent back to the clients for visualisa-

tion and manipulation.

(3) Analysis event for a design part. This event is

generated by a manufacturing analysis service to

bind the generated analysis information for a

request from a client.Each event in the second layer provides a com-

mon structure to represent information generated

and manipulated in each part of the distributed

system. However, for each event type, there are

some variations referring to different conditions

further. For example, the object event for a design

part can be further classified for different clients and

services, including clients in the collaborative

design module, Web browsers in the visualisation

module, and services in the manufacturing analysis

module. Another example is that the current model-ling system provides three kinds of methods

to create a box(starting_point, ending_point),

(starting_points, length, width, depth), and (direc-

tion_axis, starting_point, length, width, depth).

In order to represent the information in a more

flexible and extensible way, classes in the third layer

developed to inherit the respective classes in the

second layer and include the details of information

and variables. Some events defined in the system are

shown in Fig. 4.

4.2. Distributed mechanisms for functional

modules

Since the requirements of the functional modulesfor collaboration and communication are different,

several distributed mechanisms and communication

protocols are used in the system and these mechanisms

are linked effectively.

4.2.1. Java RMI for the collaborative design module

The co-design module is based on the Java RMI. The

RMI mechanism can support complex interactive com-

munications between a collaborative server and a client

so as to meet the interactive requirement of a co-design

activity effectively. According to the RMI mechanism,

through declaring remote interfaces, methods inherited

from them and implemented can be used for remote

calling and transmitting information.

The procedures of invoking remote methods are

uni-directional in a basic RMI mechanism, i.e., a client

must look up a server and call its remote methods. In

an Intranet environment, in order to enable clients to

update design information only when the server has a

new event to communicate, instead of routinely pin-

ging the server for information and creating a network

backlog, a call-back mechanism can be employed to

achieve a high-performance and robust server activity.The working process based on the call-back mechan-

ism is described as follows and depicted in Fig. 5.

(1) A list is created in a working session maintained

by the session manager to store the system

references of design clients that have joined the

session. With an input of parameters for a feature,

an input event is generated in a client. Through

invoking one of the server methodspush_E-

vent(Event e) through its remote interface, such

an event is received by the collaborative server;

(2) The input event is interpreted by the collaborativeserver and passed to the modelling workspace for

modelling; and

(3) An object event is created and is ready for

broadcasting from the server, each client re-

corded in the designer reference list is activated

to receive the event by invoking one of the

clients remote methodsreceive_Event().

In an Internet environment, firewalls between an

enterprises Intranet and the Internet block all network



9/17

traffic beyond the Intranet with the exception of

certain ports, such as the HTTP 80 port, through which

communications can be established across firewalls.

The RMI traffic is typically blocked by most of fire-

walls. In order to enable the co-design module to work

in an Internet environment, an HTTP tunnelling

mechanism introduced by Sun Co. is used to encap-

sulate RMI calls within an HTPP POST request to go

cross the 80 port. In this case, the call-back mechan-

ism is deactivated and replaced by the basic RMI

mechanismpinging the server from clients for infor-

mation updating, which is usually up to 10 times

slower. Hence, depending on the condition of a client

stay inside or outside of the firewall of the server, the

call-back- or HTTP tunnelling-based working pro-

cess are available to choose from. Due to the complex-

ity and diversity of firewalls, the HTTP tunnelling

method cannot work effectively in some cases due to

Fig. 4. Multiple-layer inheritance mechanism for defining events in the system.



10/17

the security restrictions, and this problem will be

addressed in future work.

4.2.2. Java Servlet, Applet and Web server for the

Web-based visualisation and manufacturing

analysis modules

The Web-based Java technologies (Servlet and

Applet), which can facilitate the communication in

an Internet environment, are used to establish the

infrastructures of the modules of the Web-based visua-

lisation and the manufacturing analysis services. Some

classes defined in the Web-based visualisation module

are illustrated in Fig. 6. In this module, an EventMedi-ate class in a Web Server is to co-ordinate the com-

munication between the PartHandleServletclass in the

co-design module, which is for generating visualisation

data, and the VisualisationApplet class running in a

Web browser for receiving, displaying and manipulat-

ing the visualisation data. The VisualisationAppletclass

can invoke a manufacturing analysis service wrapped

as an AnalysisServlet class for on-line evaluation.

The manufacturing analysis module consists of the

Web server shared with the visualisation module, a

look-up service to register, manage and look up

analysis services in the Web server, and analysisservices deployed in the Internet. A multiple-layer

architecture, including service wrappers, abstract

classes for services, and detailed class and method

implementations, has been designed to provide a

generic and open architecture for the services. Con-

sidering that the analysis programs are usually legacy

systems and written in C or standard Java appli-

cations, the service wrappers are used for analysis

programs to be integrated into the systems effectively

as Servlet-based services without many changes to

their native codes. With the abstract classes, theservices that have not been integrated yet can be

implemented and join the system later without re-

initialising the whole system. Details of the archi-

tecture are given in Fig. 7.

4.3. Collaborative mechanism

The process of designing a part collaboratively in

the system is depicted in Fig. 8. In the collaborative

server in the collaborative design module, a working

Fig. 5. A call-back process for clients (designers) and the collaborative server to communicate.



11/17

Fig. 6. Classes defined to exchange information between modules.

Fig. 7. A multiple-layer architecture for the manufacturing analysis module.



12/17

session can be dynamically created and accessed by

clients to provide a workspace to carry out collabora-

tive design activities, in which clients can play dif-

ferent roles and take on different responsibilities.

Within a session, a control token mechanism is

employed to control and schedule the collaborative

activity. Each session has a control token, that is, at any

one time, only the user who holds the control token isthe active designer and can edit a part; while the other

users in the same session only receive the updated

information as observers. The user who is carrying out

the edition function can become an observer by trans-

ferring his control token to another user. A project

leader is responsible to supervise the whole design

process. This project leader is authorised to schedule

the process to avoid unreasonable monopoly of the

control token and deadlocks due to network problems.

Each user is equipped with a discussion pad and an

information alert window. Through the discussion pad,users can communicate in a group or one-to-one

manner and request the control token. If there is any

change to the holding status of the control token, each

Fig. 8. Process of carrying out a design task in the system.

Fig. 9. The control process of designing a part through a control token.



13/17

user will be informed by the system automatically in

his/her information alert window. The design process

based on the control token mechanism is shown in

Fig. 9. During the working process, a new design model

is updated in the Web-based visualisation module. Any

user in the co-design and Web-based visualisation

modules can invoke a manufacturing analysis service

to evaluate a design dynamically.

Table 4

The responsibilities of three designers for a co-design task

Design members Collaborative functions Design tasks

Creation of the part Modification of the part Analysis of the part

Designer 1 Project leader (open a session) Carrier Observer Observer

Designer 2 Member (join the session) Observer Carrier Observer

Designer 3 Member (in a Web environment) Observer Observer Carrier

Fig. 10. A case study for designing a part in the integrated system.



14/17

Fig. 11. Windows supported by the CAPP service to visualise the optimisation results of a design part.



15/17

5. A case study

A case study is illustrated here to show a co-design

process with CE functions. The responsibilities ofdesigners for the task are listed in Table 4.

Some results to show a working process are given as

follows:

(1) Fig. 10a shows the display windows of Designers

A and B in the co-design module. During the

modelling process by a designer, the relevant

intermediate information is packaged as events

and shared with other designers automatically in a

design session. At the client side, the designer has

the freedom to adjust some viewing properties of

the part such as the colour, viewing position andbackground for his/her visualisation convenience

and preference, and a discussion pad and a session

manager shown in Fig. 10b are equipped in

the system. In a session manager, designers

can log on/off a session and the control token

can be exchanged. During the working process

of a designer, a discussion pad can be invoked by

any other designer in the design session to make

some comments or discussions based on a

captured picture of the design part. Designers

can chat through text or label the picture forsharing ideas.

(2) Designer C observes the design part in the Web-

based visualisation module and the part is shown

in Fig. 10c. He/she can change the visualisation

mode of the part, for example, hiding the meshes,

highlighting a feature and retrieving its para-

meters, rotating and zooming the part (see

Fig. 10d).

(3) Designer C can invoke the CAPP service from

the Web environment dynamically, and the final

optimisation results are shown in Fig. 11a.

Fig. 11b is a convenient Java2D-based visuali-sation and manipulation tool installed in each

client to observe, query, zoom and edit the

intermediate results represented as 2D informa-

tion.

6. Conclusions

In this paper, an Internet-based system, which

includes three modules for co-design, Web-based

visualisation and manufacturing analysis, has been

developed to support collaborative and CE design.

Some state-of-the-art Java and Web technologies have

been used to establish a seamless integration infra-structure for these modules, and an effective colla-

borative mechanism to organise product design has

been proposed. In the co-design module, a workspace

can be setup to organise co-design activities with co-

modelling and co-modification functions for

designers, and dynamic sessions can be created and

maintained for designers to collaborate and play dif-

ferent roles. The Web-based visualisation module

provides a portal for users to view, remark and eval-

uate a design part effectively without participating in a

co-modelling design activity and installing the co-

design module everywhere in the system. The analysis

services in the manufacturing analysis module can be

dynamically invoked by a user in a co-design com-

munity to evaluate a design part to realise the CE

methodology. In the entire system, an event-based

mechanism enables high-performance communica-

tion between functional modules, users and systems.

The main contributions of this work are summarised

as follows:

(1) The integrated system can effectively support a

dispersed team for carrying out feature-basedcollaborative design activities, with organisations

and working manners similar to actual teamwork

situations. The system provides co-modelling and

visualisation tools to meet the co-modelling or

visualisation requirements during co-design ac-

tivities within or across enterprises. Analysis

services can be invoked to conduct the CE

principle during design processes;

(2) According to the different conditions, various Java

and Web technologies have been used and

deployed in different parts of the integrated systemto meet the system requirements in terms of

efficiency and functions. Through some designed

Java-based services and event-based mechanisms,

these distributed technologies have been seam-

lessly integrated;

(3) The manipulation client modelling workspace

structure developed in the system can effectively

facilitate the consistent management of distributed

information and design models. The visualisation

model based on features can enable users to carry



16/17

out some feature-based manipulations in the Web-

based visualisation system;

(4) The multiple-layer inheritance structures de-

signed for the communication events and theintegration strategy for the manufacturing analy-

sis services ensure that the system is extensible

and scalable.

There are some technical problems in the current

system that can be improved in future work. The

information management on servers is via a file sys-

tem, which can be improved through a database

system in the future so as to maintain the information

more efficiently and effectively. In order to enhance

the performance for transferring and visualising com-

plex design parts or assemblies, a 3D streamingtechnology, which is similar to Hoops Stream Toolk-

itTM [29] and VizStreamTM [30], is being developed

and will be integrated into the Web-based visualisation

module to reduce the bandwidth requirement of using

3D design content and to enhance the visualisation

effect.

References

[1] P.G. Ranky, Current/Simultaneous Engineering: Methods,

Tools & Case Studies, CIMware Limited, Guildford, Surrey,UK, 1994.

[2] AutovueTM, Cimmetry Systems Inc., www.cimmetry.com.

[3] ConceptWorksTM, Inflow Inc., www.inflow-tech.com.

[4] eDrawingsTM, SolidWorks Inc., www.solidworks.com/edraw-

ings.

[5] StreamlineTM, Autodesk Inc., www.autodesk.com/streamline-

trial.

[6] G.Q. Huang, S.W. Lee, K.L. Mak, Web-based product and

process data modelling in concurrent design for X,

Robotics and Computer-Integrated Manufacturing 15 (1)

(1999) 5363.

[7] Y. Kim, Y. Choi, S.B. Yoo, Brokering and 3D collaborative

viewing of mechanical part models on the Web, International

Journal of Computer Integrated Manufacturing 14 (1) (2001)

2840.

[8] L.H. Wang, B. Wong, W.M. Shen, S. Lang, A Web-based

collaborative workspace using Java 3D, in: Proceedings of

Computer Supported Cooperative Work in Design, London,

Ontario, Canada, 2001, pp. 7782.

[9] A.E. Walsh, M. Bourges-Sevenier, Core Web3D, Prentice

Hall PTR, 2000.

[10] Alibre DesignTM, Alibre Inc., www.alibre.com.

[11] OneSpaceTM, CoCreate Inc., www.onespace.com.

[12] CollabCADTM, National Informatics Centre, India, www.col-

labcad.com.

[13] J.Y. Lee, H. Kim, S.B. Han, S.B. Park, Network-centric

feature-based modelling, in: Proceedings of Pacific Gra-

phics99, South Korea, 1999, pp. 280289.

[14] N. Shyamsundar, R. Gadh, Internet-based collaborative

product design with assembly features and virtual designspaces, Computer-Aided Design 33 (2001) 637651.

[15] W.D. Li, S.K. Ong, A.Y.C. Nee, Establishment of a

distributed design environment, in: Proceedings of the 9th

ISPE International Conference on Concurrent Engineering:

Research and Applications, UK, 2002, pp. 605612.

[16] Li, W.D., S.K. Ong, J.Y.H. Fuh, Y.S. Wong, Y.Q. Lu, A.Y.C.

Nee, Feature-based design in a collaborative and distributed

environment, Computer-Aided Design, in press.

[17] X.D. Liu, CFACA: component framework for feature-based

design and process planning, Computer-Aided Design 32

(2000) 397408.

[18] Y.M. Chen, M.W. Liang, Design and implementation of a

collaborative engineering information system for allied

concurrent engineering, International Journal of Computer

Integrated Manufacturing 13 (1) (2000) 1130.

[19] J.F. Gerhard, D. Rosen, J.F. Allen, F. Mistree, A distributed

product realization environment for design and manufactur-

ing, Transactions of the ASME, Journal of Computing

and Information Science in Engineering 1 (3) (2001)

235244.

[20] K.P. Cheng, Y. Pan, D.K. Harrison, Web-based design and

manufacturing support systems: implementation perspectives,

International Journal of Computer Integrated Manufacturing

14 (1) (2001) 1427.

[21] S.H. Kong, S.D. Noh, Y.G. Han, G. Kim, K.I. Lee,

Internet-based collaborative system: press-die design pro-

cess for automobile manufacturer, International Journalof Advanced Manufacturing Technology 20 (9) (2002)

701708.

[22] F.T.S. Chan, J. Zhang, P. Li, Agent- and CORBA-based

application integration platform for an agile manufacturing

environment, International Journal of Advanced Manufactur-

ing Technology 21 (6) (2003) 460468.

[23] D. Jacquel, J. Salmon, Design for manufacturability:

a feature-based agent-driven approach, in: Proceedings of

the Institution of Mechanical Engineers, Journal of Engineer-

ing Manufacture, Part B, vol. 214 (10) 2000, pp. 865880.

[24] Open CASCADETM 3D Modelling Kernel, Open CASCADE

Inc., www.opencascade.com .

[25] W.D. Li, S.K. Ong, A.Y.C. Nee, Recognising manufacturing

features from a design-by-feature model, Computer-AidedDesign 34 (11) (2002b) 849868.

[26] W.D. Li, S.K. Ong, A.Y.C. Nee, Recognising interact-

ing machining features using a hybrid AI methods, Interna-

tional Journal of Production Research 41 (9) (2003) 1887

1908.

[27] W.D. Li, S.K. Ong, A.Y.C. Nee, Hybrid genetic algorithm

and simulated annealing approach for the optimisation of

process plans for prismatic parts, International Journal of

Production Research 40 (8) (2002c) 18991922.

[28] S.K. Ong, W.D. Li, A.Y.C. Nee, STEP-based integration of

feature recognition and design-by-feature for manufacturing

http://http//WWW.CIMMETRY.COMhttp://http//WWW.INFLOW-TECH.COMhttp://http//WWW.INFLOW-TECH.COMhttp://http//WWW.INFLOW-TECH.COMhttp://http//WWW.SOLIDWORKS.COM/EDRAWINGShttp://http//WWW.SOLIDWORKS.COM/EDRAWINGShttp://http//WWW.SOLIDWORKS.COM/EDRAWINGShttp://http//WWW.AUTODESK.COM/STREAMLINE-TRIALhttp://http//WWW.AUTODESK.COM/STREAMLINE-TRIALhttp://http//WWW.AUTODESK.COM/STREAMLINE-TRIALhttp://http//WWW.ALIBRE.COMhttp://http//WWW.ONESPACE.COMhttp://http//WWW.ONESPACE.COMhttp://http//WWW.COLLABCAD.COMhttp://http//WWW.COLLABCAD.COMhttp://http//WWW.OPENCASCADE.COMhttp://http//WWW.OPENCASCADE.COMhttp://http//WWW.COLLABCAD.COMhttp://http//WWW.COLLABCAD.COMhttp://http//WWW.ONESPACE.COMhttp://http//WWW.ALIBRE.COMhttp://http//WWW.AUTODESK.COM/STREAMLINE-TRIALhttp://http//WWW.AUTODESK.COM/STREAMLINE-TRIALhttp://http//WWW.SOLIDWORKS.COM/EDRAWINGShttp://http//WWW.SOLIDWORKS.COM/EDRAWINGShttp://http//WWW.INFLOW-TECH.COMhttp://http//WWW.CIMMETRY.COM


17/17

applications in a concurrent engineering environment, Inter-

national Journal of Computer Applications in Technology 18

(1) (2003) 7892.

[29] Hoops Stream ToolkitTM, Hoops Inc., www.hoops.com.

[30] VizStreamTM

, RealityWave Inc., www.realitywave.com.[31] T.J. Nam, D.K. Wright, CollIDE: a shared 3D workspace for

CAD, in: Proceedings of the 1998 Conference on Network

Entities, Leeds, UK, 1998, pp. 389400.

[32] IX DesignTM, ImpactXoft Inc., www.impactxoft.com.

[33] G.D.F. Pahng, S. Bae, D. Wallace, Distributed modeling and

evaluation of product design problems, Computer-Aided

Design 30 (1998) 411423.

[34] E. van den Berg, R. Bidarra, W.F. Bronsvoort, Web-

based interaction on feature models, in: Proceedings of the

7th IFIP WG 5.2 Workshop on Geometric Modelling:

Fundamentals and Applications, Parma, Italy, 2000, pp. 319

320.

[35] W.M. Shen, F. Maturana, D.H. Norrie, MetaMorph II: an

agent-based architecture for distributed intelligent design and

manufacturing, Journal of Intelligent Manufacturing 11

(2000) 237251.

[36] F.L. Zhao, S.K. Tso, P.S.Y. Wu, A cooperative agent

modelling approach for process planning, Computers in

Industry 41 (2000) 8397.

[37] H.A. Sung, CyberCut: an Internet-based CAD/CAD system,

Transactions of the ASME Journal of Computing and

Information Science in Engineering 1 (2001) 5259.

[38] J. Sun, Y.F. Zhang, A.Y.C. Nee, A distributed multi-agent

environment for product design and manufacturing planning,

International Journal of Production Research 39 (4) (2001)

625645.

[39] S. Nidamarthi, R.H. Allen, R.D. Sriram, Observations fromsupplementing the traditional design process via Internet-

based collaboration tool, International Journal of Computer

Integrated Manufacturing 14 (1) (2001) 95107.

[40] G.Q. Huang, Web-based support for collaborative

product design review, Computers in Industry 48 (2002)

7188.

[41] S.Q. Zhou, K.S. Chin, Y.B. Xie, P.K.D.V. Yarlagadda,

Internet-based distributive knowledge integrated system

for product design, Computers in Industry 50 (2003)

195205.

W.D. Li received his PhD degree

from National University of Singapore.

Currently he is working in Singapore

Institute of Manufacturing Technology

as a research fellow. His research interestsinclude feature-based techniques and

application, collaborative design, applying

intelligent techniques to design and man-

ufacturing, and production process plan-

ning and scheduling. He has led some

industrial and research projects in these

areas, and has about 20 research papers in refereed international

journals and conferences.

Jerry Y.H. Fuh received his PhD degree

from the University of California at Los

Angeles (UCLA) and is currently an

Associate Professor at the Department

of Mechanical Engineering, National

University of Singapore. His research

interests are distributed CAD/CAM and

rapid prototyping and manufacturing.

He is a member of ASME and SME,

a certified manufacturing engineer

(CMfgE) from CASA/SME and a regis-

tered Professional Engineer (PE) from California, USA. He

also serves in Computers in Industry and IEEE Transaction on

Automation Science and Engineering as Associate Editor.

Y.S. Wong is an Associate Professor in

the Department of Mechanical Engi-

neering and Director of the Laboratoryfor Concurrent Engineering and Logis-

tics, National University of Singapore.

He received his PhD at UMIST (UK).

His teaching and research interests

are in machining characterisation,

modelling, monitoring, control and

optimisation; product data capture,

prototyping, design and manufacture;

and automated and integrated manufacturing system modelling

and design.

http://http//WWW.HOOPS.COMhttp://http//WWW.HOOPS.COMhttp://http//WWW.REALITYWAVE.COMhttp://http//WWW.IMPACTXOFT.COMhttp://http//WWW.IMPACTXOFT.COMhttp://http//WWW.REALITYWAVE.COMhttp://http//WWW.HOOPS.COM

03 an internet enabled integrated system for codesign and concurrent engineering

Documents