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Enabling collaborative product design through distributed engineering knowledge management Yuh-Jen Chen a , Yuh-Min Chen b, * , Hui-Chuan Chu c a Department of Accounting and Information Systems, National Kaohsiung First University of Science and Technology, Kaohsiung, Taiwan, ROC b Institute of Manufacturing Engineering, National Cheng Kung University, Tainan, Taiwan, ROC c Department of Special Education, National University of Tainan, Tainan, Taiwan, ROC Received 10 January 2007; received in revised form 13 September 2007; accepted 29 October 2007 Available online 18 December 2007 Abstract Collaborative product design (CPD) is a knowledge-intensive process that encompasses conceptual design, detailed design, engineering analysis, assembly design, process design, and performance evaluation. Each task involves various areas of knowledge and experience. However, successful collaborative product design depends on the ability to effectively manage and share engineering knowledge and experience throughout the entire development process. Consequently, the realization of distributed engineering knowledge management, which not only supports collaborative product design but also accumulates and utilizes corporate memory situated at various locations, has become one of the key tasks managed by industries. This paper presents a distributed engineering knowledge management approach for the practice of collaborative product design. In developing the proposed approach, a CPD-based engineering knowledge management methodology is first proposed under the concepts of knowledge management and collaboration. This methodology includes a knowledge management-oriented engineering management work model, a distributed engineering knowledge management framework, and rules and methods for managing engineering knowledge. The CPD-based engineering knowledge management system framework is designed, on the basis of this proposed methodology. Finally, a CPD-based engineering knowledge management system is developed using unified modeling language (UML) modeling techniques. # 2007 Elsevier B.V. All rights reserved. Keywords: Collaborative product design; Engineering knowledge management; Enterprise system; UML 1. Introduction Collaborative product design (CPD) is considered as one of the most promising business strategies for enterprises to use in addressing global competition. Practically, collaborative product design is evolving into a problem solving task that consists of acquiring requirements, defining the overall goal and task, decomposing the overall task into hierarchical sub- tasks, distributing sub-tasks to engineering designers, solving the sub-tasks, synthesizing the sub-solutions, finally providing the overall artifact solution [11,17]. Moreover, collaborative product design is involved in complicated interactions among multidisciplinary design teams in a distributed, heterogeneous and dynamic environment, including cooperation, coordina- tion, and communication [19]. Collaborative product design is a knowledge-intensive process, and includes conceptual design, detailed design, engineering analysis, assembly design, process design, and performance evaluation. Each task involves various areas of design knowledge and experience. Whether this design knowledge and experience can be effectively managed and shared is the basis of competent product design. Therefore, the implementing distributed engineering knowledge management, which not only supports design teams in various design tasks but also synthetically accumulates and utilizes corporate memory situated at various locations, is an essential feature of the most important task in collaborative product design. To achieve collaborative product design, commercial systems such as engineering data management (EDM), product data management (PDM), product information management www.elsevier.com/locate/compind Available online at www.sciencedirect.com Computers in Industry 59 (2008) 395–409 * Corresponding author. Tel.: +886 6 2757575x63922; fax: +886 6 2085334. E-mail address: [email protected] (Y.-M. Chen). 0166-3615/$ – see front matter # 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.compind.2007.10.001

Enabling collaborative product design through distributed engineering knowledge management

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www.elsevier.com/locate/compind

Available online at www.sciencedirect.com

(2008) 395–409

Computers in Industry 59

Enabling collaborative product design through distributed

engineering knowledge management

Yuh-Jen Chen a, Yuh-Min Chen b,*, Hui-Chuan Chu c

a Department of Accounting and Information Systems, National Kaohsiung First University of Science and Technology,

Kaohsiung, Taiwan, ROCb Institute of Manufacturing Engineering, National Cheng Kung University, Tainan, Taiwan, ROC

c Department of Special Education, National University of Tainan, Tainan, Taiwan, ROC

Received 10 January 2007; received in revised form 13 September 2007; accepted 29 October 2007

Available online 18 December 2007

Abstract

Collaborative product design (CPD) is a knowledge-intensive process that encompasses conceptual design, detailed design, engineering

analysis, assembly design, process design, and performance evaluation. Each task involves various areas of knowledge and experience. However,

successful collaborative product design depends on the ability to effectively manage and share engineering knowledge and experience throughout

the entire development process. Consequently, the realization of distributed engineering knowledge management, which not only supports

collaborative product design but also accumulates and utilizes corporate memory situated at various locations, has become one of the key tasks

managed by industries.

This paper presents a distributed engineering knowledge management approach for the practice of collaborative product design. In developing

the proposed approach, a CPD-based engineering knowledge management methodology is first proposed under the concepts of knowledge

management and collaboration. This methodology includes a knowledge management-oriented engineering management work model, a

distributed engineering knowledge management framework, and rules and methods for managing engineering knowledge. The CPD-based

engineering knowledge management system framework is designed, on the basis of this proposed methodology. Finally, a CPD-based engineering

knowledge management system is developed using unified modeling language (UML) modeling techniques.

# 2007 Elsevier B.V. All rights reserved.

Keywords: Collaborative product design; Engineering knowledge management; Enterprise system; UML

1. Introduction

Collaborative product design (CPD) is considered as one of

the most promising business strategies for enterprises to use in

addressing global competition. Practically, collaborative

product design is evolving into a problem solving task that

consists of acquiring requirements, defining the overall goal

and task, decomposing the overall task into hierarchical sub-

tasks, distributing sub-tasks to engineering designers, solving

the sub-tasks, synthesizing the sub-solutions, finally providing

the overall artifact solution [11,17]. Moreover, collaborative

product design is involved in complicated interactions among

multidisciplinary design teams in a distributed, heterogeneous

* Corresponding author. Tel.: +886 6 2757575x63922; fax: +886 6 2085334.

E-mail address: [email protected] (Y.-M. Chen).

0166-3615/$ – see front matter # 2007 Elsevier B.V. All rights reserved.

doi:10.1016/j.compind.2007.10.001

and dynamic environment, including cooperation, coordina-

tion, and communication [19].

Collaborative product design is a knowledge-intensive

process, and includes conceptual design, detailed design,

engineering analysis, assembly design, process design, and

performance evaluation. Each task involves various areas of

design knowledge and experience. Whether this design

knowledge and experience can be effectively managed and

shared is the basis of competent product design. Therefore, the

implementing distributed engineering knowledge management,

which not only supports design teams in various design tasks

but also synthetically accumulates and utilizes corporate

memory situated at various locations, is an essential feature

of the most important task in collaborative product design.

To achieve collaborative product design, commercial

systems such as engineering data management (EDM), product

data management (PDM), product information management

Y.-J. Chen et al. / Computers in Industry 59 (2008) 395–409396

(PIM), technical document management (TDM), and technical

information management (TIM) offer a structured way of

efficiently storing, integrating, managing and controlling both

data and engineering processes from design, through manu-

facturing, to distribution [15]. However, the above application

systems do not consider support for collaborative design

activities and processes in the true knowledge management

context, making it impossible to apply them to design

knowledge.

Furthermore, most conventional knowledge management

systems can only be used to help in document management,

engineering data management or workflow management

[4–7,13,16,18,22]. No effective and practical system exists for

capturing, storing, compiling, and retrieving design knowledge

and experience in collaborative product design. This circum-

stance causes a bottleneck in managing and sharing valuable

product information, design knowledge and experience in

collaborative and distributed design environments.

This study presents a distributed engineering knowledge

management approach for the practice of collaborative product

design. A CPD-based engineering knowledge management

methodology is proposed under the concepts of knowledge

management [2] and collaboration [12]. This methodology

development primarily includes domain investigation, a

knowledge management-oriented engineering management

Fig. 1. Steps of the pr

work model, a distributed engineering knowledge management

framework, and rules and methods for managing engineering

knowledge. A CPD-based engineering knowledge management

system framework is designed based on this methodology. The

system framework design is achieved via the systematic steps

of (i) objective identification, (ii) functional requirement

analysis, and (iii) system framework design. Finally, a CPD-

based engineering knowledge management system is devel-

oped using UML modeling techniques.

The results enable the practice of collaborative product

design and, subsequently, help engineering designers to

develop high quality products efficiently.

2. Overview of the proposed approach

This section introduces an overview of the proposed

approach towards developing distributed engineering knowl-

edge management for supporting knowledge-intensive design

in a collaborative environment. The proposed approach mainly

includes the four phases of CPD-based engineering knowledge

management methodology development, CPD-based engineer-

ing knowledge management system framework design,

enabling technology development and implementation, and

system construction. Each phase involves several steps as

illustrated in Fig. 1.

oposed approach.

Y.-J. Chen et al. / Computers in Industry 59 (2008) 395–409 397

2.1. Phase I: CPD-based engineering knowledge

management methodology development

During this phase, collaborative product design is defined

first. Characteristic analysis of collaborative product

design is then performed based on this definition. Addition-

ally, the engineering knowledge elements involved in

collaborative product design are also identified. Based on

the identified knowledge elements and the concept of

knowledge management, the KM-oriented engineering

knowledge work model is proposed. Subsequently, the

distributed engineering knowledge management framework

is developed based on the characteristics of collaborative

product design.

2.2. Phase II: CPD-based engineering knowledge

management system framework design

The system objective is stated first based on the

methodology developed in Phase I. Moreover, system

functional requirements are analyzed from two perspectives,

i.e., the characteristics of collaborative product design and the

system functionality for knowledge management. The system

framework is designed according to the functional require-

ments.

2.3. Phase III: system realization

Tasks in system realization include system modeling,

system architecture design, and system implementation.

Meanwhile, system modeling includes the steps of use

case modeling, class modeling and dynamic modeling.

System modeling aims to build a design model based on the

results of functional analysis but containing implementation

details. The details are added to the design model in

accordance with the strategy established during system

design. In the proposed approach, UML modeling techniques

are employed to define the structures and behaviors of the

elements in the system as well as the relationships among the

elements. The result of system modeling is a set of object

classes that corresponds to the elements in the system.

According to the results of system design and system

modeling, the system architecture is designed for system

implementation.

3. CPD-based engineering knowledge management

methodology development

This section first examines the characteristics and under-

lying knowledge elements of collaborative product design.

Based on these characteristics and knowledge elements, a

CPD-based engineering knowledge management methodol-

ogy is then developed, which includes (i) a knowledge

management-oriented engineering management work model,

(ii) a distributed engineering knowledge management frame-

work, and (iii) rules and methods for managing engineering

knowledge.

3.1. Domain investigation

3.1.1. Characterization analysis

Collaborative product design refers to the integration of

distributed design work by sharing knowledge rather than by

exchanging conventional data. In a collaborative product design

environment multiple designers in different disciplines and

from different enterprises cooperate to develop a complex

design on the basis of common consensus, trust, and

cooperation.

The above concept of collaborative product design can be

implemented by the following enabling capabilities: (i) remote

process formation, control, coordination and communication,

(ii) dynamic integration of design activities, application

systems, and knowledge, and (iii) management and sharing

of various knowledge from heterogeneous resources.

Therefore, the process of collaborative product design has

the properties of: (i) product-centered and dynamic-configur-

able process, project-based process management, flexibility

and heterogeneity environment, hierarchical and recursive

structure, and distributed and cooperativeness.

In addition to the identified properties of collaboration

model from the system operation aspect, some factors involved

in the human attitude should be considered to make the

collaboration successful. They are discussed below.

3.1.1.1. Team alignment needed. Team alignment can quickly

create a common sense of purpose and shared commitment to

action, which includes contextual agreement, alignment of

working styles, team chartering, rules of the game and non-

negotiable behaviors.

3.1.1.2. Effective partnerships needed. Effective partnerships

improve human interactions to create more efficient and

effective strategic alliances, partnerships or external collabora-

tions. Success of strategic alliances and partnerships largely

depends on the ability of people to interact well, create mutual

trust, define expectations and rules of the game, and manage the

relationship.

3.1.2. Engineering knowledge identification

Engineering knowledge identification attempts to identify

knowledge elements involved in collaborative product design to

facilitate the design of a knowledge management-oriented

engineering management work model.

By examining designer behavior in product design, four

knowledge-intensive structured design methods and related

knowledge elements are identified as shown in Fig. 2. They are

detailed below:

� F

eature-based design: A library of features such as design

primitives is applied in product modeling. Product functional

requirements are transformed into functional features,

followed by conversion into design specifications and

manufacturing features [1,8]. Design knowledge involved

in feature-based design thus includes ‘‘design intent’’,

‘‘engineering principles’’, ‘‘design experience’’, ‘‘creativ-

Fig. 2. Classification of engineering knowledge involved in product design.

Y.-J. Chen et al. / Computers in Industry 59 (2008) 395–409398

ity’’, and ‘‘product information’’. Meanwhile, product

information can be subdivided into ‘‘customer require-

ments’’, ‘‘functional requirements’’, ‘‘design features’’, and

‘‘engineering specifications’’.

� E

ngineering change: Engineering change is usually defined

as a change to the form, fit or function of a product or part to

satisfy customer requirements. Engineering change is

triggered by engineering change requests, following which

the engineering change is proposed, investigated, authorized/

rejected, executed, reviewed, and archived in an orderly

structured design manner [8]. Engineering change knowledge

can be specialized as change knowledge, which can be

Fig. 3. KM-oriented engineering m

classified into ‘‘change reason’’, ‘‘change content’’, and

‘‘applied engineering principles’’.

� D

esign by modification/Design by reference: Design by

modification or by reference usually is adopted to reduce

design time and increase work efficiency for designers. In this

design method, the most similar engineering model and

associated knowledge can be retrieved from the historical

knowledge repository by querying customer requirements,

functional requirements, design features or engineering

specifications, which are then slightly modified to create a

new engineering model, or are used as reference model for a

new design. Design knowledge involved in both design by

anagement work model.

Y.-J. Chen et al. / Computers in Industry 59 (2008) 395–409 399

modification and design by reference comprises ‘‘product

information’’, ‘‘design intent’’, ‘‘engineering principles’’,

and ‘‘design experience’’.

3.2. Knowledge management-oriented engineering

management work model

Knowledge management attempts to ensure growth and

continuity of performance by protecting critical knowledge at

all levels, applying existing knowledge in all pertinent

circumstances, combining knowledge management in syner-

gistic ways, continuously capturing, managing, and sharing

relevant knowledge, and developing new knowledge through

continuous learning that builds on internal experiences and

external knowledge.

Consequently, knowledge management for collaborative

product design should consider capabilities of capturing,

managing and sharing related knowledge of a working design

and archiving all knowledge of regarding a performed design

into the reference knowledge repository throughout collabora-

tive product design activities. As shown in Fig. 3, the KM-

oriented engineering management work process is initiated by

establishing a design project and defining design activities.

Designers create engineering models during design execution.

Following the project completion, knowledge related to the

engineering model is captured when the engineering model is

checked into the project knowledge repository.

The engineering models in the project knowledge repository

can be checked out, copied and referenced while retrieving

related knowledge. During check out, an engineering model can

be modified based on changes in product requirements or

Fig. 4. Distributed engineering know

relevant engineering principles. The reasons for engineering

change and the applied engineering principles can be captured

when the revised engineering model is checked into the project

knowledge repository.

After the completion of a design project, the engineering

models and related knowledge are archived in a reference

knowledge repository. These reference engineering models and

related knowledge can then be referenced or copied as a

reference model for a new design project.

3.3. Distributed engineering knowledge management

framework

As shown in Fig. 4, the distributed engineering knowledge

management framework for collaborative product design is

designed based on the capabilities of collaborative product

design discussed in Section 3.1.1. In this study, ‘‘personal

knowledge management’’ and ‘‘team knowledge management’’

of engineering knowledge management are proposed to support

levels of knowledge management in a collaborative product

design project. Personal knowledge management is responsible

for knowledge management for individual team members, and

provides a connection to a team knowledge management unit,

while team knowledge management is responsible for knowl-

edge management of a collaborative team unit. The latter can be

equipped with a team knowledge repository and can commu-

nicate with other team knowledge management units.

Furthermore, two levels of knowledge repositories are also

designed for knowledge storage, namely ‘‘personal knowledge

repository’’ and ‘‘team knowledge repository’’. Managed by

personal knowledge management, a personal knowledge

ledge management framework.

Y.-J. Chen et al. / Computers in Industry 59 (2008) 395–409400

repository is a private storage area for individual team

members. Meanwhile, a team knowledge repository is a group

storage area managed by team knowledge management.

3.4. Methods and rules for distributed engineering

management framework

Based on the KM-oriented engineering management work

model and distributed engineering knowledge management

framework discussed in Section 3.3, the life cycle of

engineering knowledge elements are drawn as shown in

Fig. 5. Methods and rules to state transition of engineering

knowledge elements are discussed below:

(i) G

et allows the designer to select an engineering

knowledge element and bring it to a workbench from a

bin.

(ii) P

ut away allows the designer to store an engineering

knowledge element in a selected bin.

(iii) C

heck_in & Knowledge Capture allows designers to

release product items from their personal work places into

a team knowledge repository, and requests designers to

describe their design knowledge, such as design intent,

design experience, change intent, change content, and so

on.

(iv) A

rchive allows product items and captured engineering

knowledge to archive in a reference knowledge repository

when the project is accomplished.

(v) C

ompile can transform description knowledge in a team

knowledge repository into rule-based engineering knowl-

edge.

(vi) C

onsult allows designers making question queries to a

knowledge base and obtaining relevant decision knowl-

edge.

Fig. 5. Life cycle of engineering knowledge elements.

(vii) R

etrieval allows designers to obtain historical engineer-

ing knowledge elements for design by reference or design

by modification.

(viii) C

heck_out allows the designers to have full privileges for

modification. Once checked out, the engineering knowl-

edge element is locked so that no one else can check it

out.

(ix) T

ransmit allows designers to send product or engineering

knowledge elements to a specified destination or an

activity work place.

(x) I

mport allows designers to receive product or engineering

knowledge elements from other activities.

4. CPD-based engineering knowledge management

system framework design

This section defines the objective of the CPD-based

engineering knowledge management system based on

the proposed CPD-based engineering knowledge manage-

ment methodology. Next, the system functional require-

ments are analyzed to guide the design of the system

framework.

4.1. System objective statement

The CPD-based engineering knowledge management

system is identified as ‘‘to provide engineering designers

with easy capture, management and reuse of relevant

design knowledge throughout collaborative product design

activities.’’

System functions that may help achieve this objective can be

identified from two perspectives, namely (i) the functionality to

fulfil the characteristics of collaborative product design, and (ii)

the functionality for knowledge management.

4.2. System functional requirements analysis

Designers in collaborative product design activities are

permitted to work on the following: (i) checking in an

engineering model to a model library, and capturing, storing

and compiling related engineering knowledge in a team

knowledge repository within the knowledge-intensive struc-

tured design methods; (ii) retrieving a historical engineering

model and associated knowledge from a reference knowledge

repository as valuable references in the structured product

design procedure, which contains four establishment phases of

‘‘customer requirement’’, ‘‘functional requirement’’, ‘‘func-

tional feature’’, and ‘‘engineering specification’’, and (iii)

querying rule-based engineering knowledge to solve design

problems.

Besides the above knowledge management-oriented func-

tional requirements, the functional requirements to meet the

characteristics of collaborative product design such as

reconfigurability, project-based process management, highly

processed communication, coordination and control, and

hierarchical and distributed process structure are also

considered in designing the system framework.

Y.-J. Chen et al. / Computers in Industry 59 (2008) 395–409 401

4.3. System framework design

This subsection designs the framework of the CPD-based

engineering knowledge management system based on the

system functional requirements. Fig. 6 shows the system

framework as a knowledge management life cycle, which

consists of the ‘‘creation’’, ‘‘capture’’, ‘‘compilation’’ and

‘‘integration’’ and the ‘‘retrieval/query’’ of engineering knowl-

edge. The elements in the knowledge management life cycle are

briefly summarized below.

� E

ngineering knowledge creation

As discussed in Section 3.1.2, engineering knowledge is

generally involved in the structured design methods of

Fig. 6. CPD-based engineering knowledge

feature-based design, engineering change, design by mod-

ification, and design by reference. Accordingly, designers can

clearly create relevant engineering knowledge through

conducting these various structured design methods.

� E

ngineering knowledge capture, storage and compilation

Design intent, applied engineering principles and heur-

istics and information related to engineering collaboration

can be extracted during the engineering design process, and

are associated with the design object as reference notes.

When an engineering model has been completed and checked

in-to a project knowledge repository, product information and

knowledge on the engineering model are captured and stored

in the product information and engineering knowledge

libraries, respectively. Additionally, the product information

management system framework.

Y.-J. Chen et al. / Computers in Industry 59 (2008) 395–409402

and engineering knowledge are compiled in rule format and

deposited in an engineering rule base. Upon completion of a

design project, the engineering models and associated

knowledge are stored in a historical knowledge repository

for later reuse.

� E

ngineering knowledge retrieval/query

Product information and engineering knowledge can be

retrieved when an engineering model is examined or copied

from the project knowledge repository. Similarly, historical

engineering models, related product information and

engineering knowledge can also be referenced or copied to

provide a reference source for new projects. Furthermore,

engineering designers can conveniently query engineering

knowledge using the knowledge query function to solve

related design problems.

5. System realization

System realization involves three phases of ‘‘system

modeling’’, ‘‘system architecture’’, and ‘‘system implementa-

tion’’. They are detailed in Sections 5.1, 5.2, and 5.3,

respectively.

5.1. System modeling

System modeling aims to define levels of system details in

terms of a set of models. Two conductions are applied in the

system modeling. First, the system must fully embrace and

comply with industry standard object models and architec-

ture to enable interoperability with other engineering data

management modules and a wide variety of other application

software systems. Second, the system must employ

industry’s best practice modeling techniques in a proposed

development process to facilitate the management of system

complexity.

The system modeling phase employs unified modeling

language (UML) [3,14,20], because UML emerged as the

notational standard for object-oriented modeling. Standard

modeling techniques may standardize and facilitate the

development process through common concepts, notations

and supporting tools and thus increase compatibility with other

software systems.

The system modeling phase involves steps of use case

modeling, class modeling, and dynamic modeling as discussed

below.

5.1.1. Use case modeling

Use case modeling has two purposes: (i) to capture the

functional requirements of a system before undertaking

detailed design work and (ii) to create a seamless transition

from business processes to software systems. Based on [1], a

use case describes all the details of a business process by

viewing customers as users and the business process as a case of

how they use the business. The business process is thus viewed

as ‘‘a behaviorally related sequence of interactions performed

by an actor in a dialogue with the system to provide some

measurable value to the actor’’. Use case represents ways of

using a system in terms of sets of scenarios, where actors

represent roles that have specific sets of responsibilities relating

to use case.

5.1.1.1. Identifying use cases. The process modeling section

treats the engineering knowledge management methodology

as the most serious of the processes. Each process is further

broken down into elementary business activities. The

elementary business activities provide a good basis for

identifying use cases. The relationships between elementary

business activity use case are potentially many to many.

However, since an elementary business activity is constrained

to being performed in terms of one or more business steps by

one person in one place or a group of people in one or more

locations in collaboration, an elementary business activity

generally corresponds to one (or occasionally two or three) use

cases.

In contrast to some methods, which allow a use case to span

several external system events and become excessively

complex, the proposed development procedure treats each

use case as a self-contained unit of interaction with no

intervening time delays. The use case must be performed by a

single actor in a single place, although it might result in output

flows that are sent to other passive actors.

5.1.1.2. Identifying actors. Actors are classified into business

actors and system actors. Business actors can be identified from

the ‘‘resources’’ or ‘‘mechanism’’ indicated in the proposed

business process model. System actors, as opposed to business

actors, are the actors of use cases. Business actors frequently

correspond individually with system actors but this need not

always be the case. Two business actors could correspond to a

single system actor if they both play the same role with respect

to the same system interface.

In engineering knowledge management, most of the

business actors in the collaborative product design process

are system actors who use the system functions to perform their

duties. Therefore, system actors can be used to help drive the

use case modeling by identifying the roles they play as well as

the actions or steps they take to play the role.

5.1.1.3. Identifying events. Use cases are triggered by external

system events, which assume the existence of a business

process-computer system boundary. Therefore, external system

events can help drive the use case modeling. As discussed in the

section on business process modeling, this study identified

business events that trigger elementary business activities.

Essentially, a business event may correspond to one or more

external system events depending on the system design.

Occasionally, an external system event may stem from a

number of different business events.

5.1.1.4. Creating use case diagrams. According to both

elementary functions and actors, several use cases are identified

and grouped into use case diagrams in terms of actors, such as

designer, project manager, and application system. Fig. 7 shows

the use case diagram of a designer.

Fig. 7. Use case diagram.

Fig. 8. Class diagram.

Y.-J. Chen et al. / Computers in Industry 59 (2008) 395–409 403

Y.-J. Chen et al. / Computers in Industry 59 (2008) 395–409404

5.1.1.5. Describing use cases. Use case description attempts

to clarify the interactions between the actor and the system

through describing what, and how, the actor is doing by using

the system, instead of what the system is doing. The description

includes the purpose of the use case and the detailed flow of

events that follow the initiation of a use case. The following is a

description of the use case ‘‘Knowledge Retrieval’’.

5.1.2. Class modeling

Class modeling aims to identify the classes that are involved

in engineering knowledge management and their relationships.

Fig. 9. Sequence diag

Fig. 10. State diagra

It produces class diagrams that define the static, structural, and

data aspects of the system framework in terms of classes and

relationships that correspond to elements of engineering

knowledge management. This process helps promote under-

standing of real world engineering knowledge management and

thus provides a practical basis for system implementation.

A class diagram consists of classes, links and associations. A

class is a set of objects that share common attributes,

operations, semantic structure and behavior. An ‘‘object’’ is

a concept, abstraction, or thing in a certain application domain.

Meanwhile, a ‘‘link’’ is a physical or conceptual connection

ram (an example).

m (an example).

Y.-J. Chen et al. / Computers in Industry 59 (2008) 395–409 405

between instances of classes. Finally, an ‘‘association’’

describes a group of links that share a common structure

and semantics. Two of the most commonly used associations

are generalization and aggregation. Aggregation is the

‘‘part_of’’ relationship in which lower-level classes are

associated as a higher-level aggregate class. Meanwhile,

general-subclasses are a specialization of their super-class.

In the notation of UML, a class is indicated by a rectangular

box with three regions; class name, list of attributes, and list of

operations. An association is drawn as a line between classes,

with which a verb in a problem statement is associated.

Similarly, the UML notation for a link is a line between objects.

Meanwhile, an aggregation is drawn like an association, except

a small diamond that indicates the assembly end of the

relationships. Finally, the generalization is signified by a

triangle connecting a super-class to its sub-classes.

5.1.2.1. Discovering classes. Classes involved in engineering

knowledge management can be identified from various aspects.

These aspects include (i) the business process aspect from the

business process model, (ii) system organization aspect from

designed ‘‘system framework and configuration’’, and (iii)

system modeling aspect from use cases.

The business process aspect identifies elements involved in

the engineering knowledge management from the business

process model, and then maps them into classes in the system.

Classes discovered in this way are mostly those that process

actors can directly interact with, including information items,

process activities, and business level system functions (or

functional classes). They are referred to as ‘‘entity classes’’.

The use case analysis approach identifies objects by

examining the nouns and noun phrases from the use case

Fig. 11. System

description, which represent the key concepts significant to the

domain, and fulfil the definition of class and object. The nouns

and noun phrases may be objects, descriptions of the state of an

object, and external entities and/or actors. Classes identified in

this approach are mostly those that provide generic mechanisms

to support business level functionality.

5.1.2.2. Developing class diagram. Initially, use case descrip-

tions are analyzed for verbs, which reveals operations on

existing classes, and also new classes to provide the services

indicated by the verbs. Association, like operations, can also be

found by searching for verbs in source documents. While

operations reflect required functionality, associations reflect

required structural relationships between classes. At this stage,

the key object classes and their relationships, which are

identified from a process model, are drawn as an abstraction of a

class diagram.

The abstracted class diagram is then refined into a detailed

class diagram by specializing classes, refining class relation-

ships, and adding classes identified from use case analysis.

Fig. 8 illustrates the class diagram of a CPD-based distributed

engineering knowledge management system.

5.1.3. Dynamic modeling

Dynamic modeling addresses the dynamic behavior of

objects via the different events and associated state changes that

can happen to an object during different time periods. This

includes scenario analysis and state modeling.

5.1.3.1. Scenario analysis. A scenario is a sequence of

particular events that occur during the execution of a system.

Scenario analysis is performed by sequentially arranging the

architecture.

Y.-J. Chen et al. / Computers in Industry 59 (2008) 395–409406

events shown in use case descriptions. Scenario analysis results

in sequence diagram of object interactions arranged sequen-

tially. Fig. 9 depicts the sequence diagram of ‘‘Knowledge

Retrieval’’.

5.1.3.2. State modeling. The sequence diagram also indicates

events that trigger each object and events that are generated

from each object. Once identified, these events can be used to

define the state transition diagram of each object class. A state,

which is an abstraction of the attribute values and links of an

object, specifies the response of the object to input events. The

response to an event depends on the state of the object receiving

it and can include the object changing state, or sending another

event to the original sender or to a third object. A state diagram

that links states through events describes the behavior of a

single class of objects. Each event corresponds to a method of

the object. Fig. 10 represents the state diagram of class ‘‘a

engineering knowledge element/item’’.

Fig. 12. The user scenario for the functional feature and engineering specifica-

tion-based reference design retrieval.

5.2. System architecture design

The system architecture indicates the internal components

and packages, which make up the system, and their interactions.

Packages and components in the architecture are arranged in a

hierarchy of layers where each layer has a well-defined

interface.

The system architecture is developed by grouping classes

into components that have either a cooperative function or that

needed to be in close proximity for implementation efficiency.

Logically related components are then grouped into packages,

similar to components.

Generally, the top-level components of the packages in the

system architecture correspond directly to the modules defined

in the system framework, while the lower-level components are

added to implement the functions to support higher-level

components, but are not directly presented to users.

The architecture of the proposed system is designed based

on the concept of a three-tier distributed object technology. The

architecture is organized in three tiers of user presentation

business logic, and data management, as Fig. 11 shows. The

significance of the architecture is that the modularized software

components can be moved around at execution time and

deployed to optimize the technology and deliver the maximum

business benefit by separating user interface code, business

logic code and data storage code.

5.3. System implementation and scenario

Based on the results of system design and modeling, a CPD-

based engineering knowledge management system and the

involved core functions [9,10,21] were developed and

implemented in a virtual environment constituted by the

Enterprise System Engineering (ESE) Laboratory at National

Cheng-Kung University, Taiwan, and the Knowledge Manage-

ment System (KMS) Laboratory at Kaoshiung Medical

University, Taiwan. The former, which is equipped with Acer

ALTOS 9000 PC servers and Acer Power 590 h PC workstation

Fig. 13. Interface for identifying functional features and engineering specifica-

tions.

Fig. 14. Interface for ranking similarity of retrieved design cases.

Fig. 15. The engineering model of t

Fig. 16. The related engineering know

Y.-J. Chen et al. / Computers in Industry 59 (2008) 395–409 407

networked with five PC clients under Windows-NT environ-

ment, acts as a prime enterprise. The latter, which is equipped

with a SUN Space 20 workstation, a Silicon Graphics INDY

workstation, a Power Macintosh 6100/60, and an Acer ALTOS

9000 PC, plays the roles of guests, customers, remote

employees, and allied teams.

The applicability and feasibility of the model and the

framework have been examined by conducting a mold design at

Yong-Shiuh Mold Corporation, Taoyuan, Taiwan. According to

the investigation on the designers in the Mold Corporation, the

benefits of using the system include: (1) enhancing the

efficiency of collaborative design model by retrieving and

sharing distributed engineering design cases (engineering

knowledge), (2) increasing the trust among designers in

sharing distributed engineering knowledge, and (3) decreasing

the designer’s design time and cost in referring to the retrieved

similar design cases.

To describe the developed system with application in this

mold design, the functional feature and engineering specifica-

tion-based reference design retrieval is taken as an illustrative

example. Its user scenario is provided in Fig. 12 to address how

he most similar design case 07.

ledge of the engineering model.

Y.-J. Chen et al. / Computers in Industry 59 (2008) 395–409408

the retrieval is to be used. Fig. 13 shows the interface of

identifying the functional features and engineering specifica-

tions for the designers, while Fig. 14 shows the similar ranking

for the retrieved design cases. Moreover, Figs. 15 and 16

present the engineering knowledge contents of the most similar

design case. Meanwhile, Fig. 15 illustrates the engineering

model as a reference model for a working design, and Fig. 16

shows the relevant engineering knowledge of the engineering

model, including design intent and design experience of

establishing functional features and engineering specifications

on the engineering model.

6. Conclusions and further research

This work provides (i) a methodology for engineering

knowledge management in the context of collaborative product

design, (ii) a CPD-based engineering knowledge management

system characterized by reconfigureability and flexibility,

platform independence, and cooperativeness, and (iii) UML-

based enterprise system development procedure.

This work used the concepts of enterprise integration to

develop an engineering knowledge management methodology,

which includes a knowledge management-oriented engineer-

ing management work model, a distributed engineering

knowledge management framework, and rules and methods

for managing engineering knowledge. Rather than providing

point system functionality, this methodology offers a solution

for knowledge management in the context of collaborative

product design. The knowledge management-oriented engi-

neering management work model shows associativity between

collaborative product design and knowledge management. The

hierarchical and distributed management framework provides

a basic construct for developing system architecture compa-

tible with collaborative product design processes. The rules

and methods reveal the business logic for knowledge

management as well as the potential system functional

requirements.

Additionally, this work developed the CPD-based engi-

neering knowledge management system based on the

proposed methodology by applying principles for using

standardized modeling techniques, models and architectures

to make the system fully compatible and interoperable with

enterprise systems. The management system mainly consists

of modules of project management, knowledge management,

and knowledge service. Meanwhile, some core technologies

involved in the knowledge service such as ‘‘customer

requirement-based reference design retrieval’’, ‘‘functional

requirement-based reference design retrieval’’, ‘‘functional

feature-based reference design retrieval’’, ‘‘engineering

specification-based reference design retrieval’’, and ‘‘knowl-

edge compilation’’ were separately developed and imple-

mented in [9,10,20].

This study also demonstrated a systematic procedure for

developing an enterprise system that meets the needs of a large

business with complex business processes. It provides grounds

for a transition from domain processes, through solution

process to system models and architecture. This approach may

accelerate the development process of enterprise systems and

make systems more applicable.

Besides a structured methodology for developing and

implementing the engineering knowledge management systems

in collaborative design organizations, the system also provides:

(i) an effective method for recording both explicit and tacit

engineering knowledge, (ii) a convenient method for engineer-

ing knowledge reuse, and (iii) a valuable reference model and

framework that can be applied for other knowledge-intensive

works such as software system development, planning or

diagnosis.

Results of this study can increase product development

capability and quality, reduce development cycle time and cost,

and ultimately increase product marketability.

The major research direction for the future will be the

elicitation, integration and sharing of product knowledge with

human attitudes or cognition issues in collaboration environ-

ments. We will integrate knowledge management and human

factors/cognition techniques to develop relevant technologies,

such as knowledge elicitation technology and knowledge

building technology.

Acknowledgements

We would like to thank the anonymous reviewers for their

valuable comments, which have greatly improved the

presentation of this paper. This research was sponsored by

the National Science Council, Taiwan, ROC under Grant

numbers NSC93-2212-E-006-021 and NSC93-2917-I-006-

017.

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Dr. Yuh-Jen Chen is currently an assistant professor

of Department of Medical Information Manage-

ment, Kaohsiung Medical University, Taiwan,

ROC. He received his PhD and MS degrees in

Institute of Manufacturing Engineering of National

Cheng Kung University in 2005 and 2001 respec-

tively, and gained his BS degree from the Depart-

ment of Mathematics of Chung Yuan Christian

University, Taiwan, ROC, in 1999. His current

research interests include enterprise system devel-

opment and integration, knowledge engineering and management, and med-

ical informatics.

Dr. Yuh-Min Chen is currently a professor of Insti-

tute of Manufacturing Engineering, National Cheng

Kung University, Taiwan, ROC. He graduated from

The Ohio State University with a PhD degree in

Industrial and Systems Engineering in 1991 and

received his MS and BS degrees from National Tsing

Hua University, Taiwan, ROC, in 1981 and 1983,

respectively. Before joining the faculty of Institute of

Manufacturing Engineering in 1994, he worked as a

research engineer in Structural Dynamics Research

Corporation, USA for three years. His current research interests include

enterprise integration, engineering data and knowledge management, compu-

ter-aided concurrent engineering, and manufacturing information systems.

Dr. Hui-Chuan Chu is an associate professor of

Department of Special Education, National Univer-

sity of Tainan, Taiwan, ROC. She received her PhD

degree from Columbia University in 1998. Her

research interests are knowledge management, tea-

cher knowledge and integration of information tech-

nology in teacher education.