U_VBOOM : UNIFIED ANALYSIS AND DESIGN PROCESS

BASED ON THE VIEWPOINT CONCEPT

Abdellatif Hair

Faculty of Sciences and techniques P.O. Box. 523 BENI MELLAL MOROCCO

Keywords: Analysis/ Design process, modeling, Viewpoint, UML.

Abstract: The introduction of viewpoint in object-oriented design provides several improvements in modeling

com

plex systems. In fact, it enables the users to build a unique model accessible by different users with

various points of view, instead of building several sub-models whose management is too hard to complete.

Those concepts of view and viewpoint were implemented by VBOOL, the language which propose a new

relationship "the visibility". VBOOM, the analyze/design method, integrates those concepts in an object-

oriented modeling. The aims of this work are, firstly to propose a new representation of the visibility

relationship of VBOOL in UML standard language for modeling and specifying object-oriented systems.

Secondly, to complete UML by an oriented viewpoint method to get a complete software engineering

process. The definition of this method is based on VBOOM method. This method is called U_VBOOM,

which represents an adaptation of VBOOM in UML. The new representation of the visibility relationship

encourages the multi-targets code generation and improve the process of development proposed by the

VBOOM method.

1 INTRODUCTION

Recently, two aspects have received a lot of

attention in object-oriented development: the

emergence of Unified Modeling Language (UML)

as an unified notation for object-oriented analysis

and design, and by integrating viewpoint approaches

to software development.

The UML (Rumbaugh, 1999) can be seen as the

success

or of the wave of object-oriented analysis

and design methods that appeared in the late 80s and

early 90s. It unifies the methods of Booch (Booch,

1994) , Rumbaugh (OMT) (Rumbaugh, 1989) , and

Jacobson (OOSE) (Jacobson, 1992) . The UML is a

standard language for modeling and specifying

object-oriented systems. It gives notations for

describing a system in various views, but does not

define any specific process for software

development, beyond some preliminary process

description reported, for instance, in (Krutchen,

2000) (OMG, 2001) .

The introduction of viewpoint approaches to

soft

ware development provides several

improvements in complex system modeling (Carré,

1991) (Finkelstein, 1993) (Mili, 1999). In fact, it

enables the users to build a unique model accessible

by different users with various viewpoints, instead

of building several sub-system whose management

is too hard to complete. The concept of viewpoints

was first introduced by Shilling and Sweeny

(Shilling, 1989) as a filter of a global interface of

the class, but the views are not separable or

separately reusable. Harrison and al. proposed

subject-oriented programming as a way to build

integrated “multiple view” applications by

composing application fragments, called subjects,

which represent compilable and possibly executable

functional slices (Harrison, 1993) .

To this effect, the VBOOL (View Based Object

Ori

ented Language) language has been defined

which integrate the new relation "the visibility" and

its derived mechanisms (language that extend Eiffel)

(Marcaillou, 1995) . To implement those concepts in

object-oriented methodology, the VBOOM (View

Based Object Oriented Method) method has been

defined which extends the BON's method (Coulette,

1996) (Kriouile, 1995) . VBOOM propose 3 stages.

The first one defines the system dictionary. The

second one allows designer to develop their own

model separately. This stage meets the need of users

to focus on their specification.

The aims of this work is, firstly to propose a new

represen

tation of the visibility relationship of

VBOOL in UML (Unified Modeling Language)

217

Hair A. (2004).

U_VBOOM : UNIFIED ANALYSIS AND DESIGN PROCESS BASED ON THE VIEWPOINT CONCEPT.

In Proceedings of the Sixth International Conference on Enterprise Information Systems, pages 217-224

DOI: 10.5220/0002597702170224

 SciTePress

(Jacobson, 1993) (OMG, 2001) (Rumbaugh, 1999).

Secondly, to complete UML by an oriented

viewpoint method to get a complete software

engineering process. The definition of this method is

based on VBOOM method.

This article is organized as follows: in section 2,

we define briefly the visibility relationship and it's

derived concepts in UML. The section 3 deal with

present principles of the VBOOM method under the

UML standard (named thereafter U_VBOOM). We

conclude by a survey of work done and a

presentation of its perspectives after a presentation

of the relative works.

In this paper, we are going to illustrate our

subjects with the Media library Management

example. The specifications of this example are

more explained in (Lopez, 1998) . The Media

library system must allow its members to consult

and to borrow various types of support: books, video

and audio disks, audio CD, etc. Only one member of

the library can borrow books, reviews, etc. The

borrow is limited in time. The potential users of the

Media library system are: the librarian who

manages the loans, the person in charge of

adhesions who will add and withdraw members, the

person in charge of exemplaries who will seize the

new exemplaries and to withdraw those damaged,

and finally the system engineer who ensures the

good exploitation of the system for the users.

According to the use types, the Media library system

will be considered, as a set of COUNTS

ADHERENTS, or of EXEMPLARIES, or a means

to facilitate the LOANS. Thus, we identify 4 classes

of the system: "

Media_Library", "Loans",

Exemplaries" and "Counts_Adherents".

2 THE VISIBILITY

RELATIONSHIP: ASSOCIATED

MECHANISMS AND SYNTAX

By visibility, we mean that an entity can be seen

upon several angles. It's the fact of a satellite which

can be studied under the mechanic angle, thermal or

informative one. The syntax and the semantic of this

concept is detailed in (Marcaillou, 1995) , we

summarize here the principal characteristic.

A view is an abstraction of the model. It

constitutes the unity of visibility, it is the result of

factorizing user's needs.

A viewpoint is the sight that has a user to the

model. It 's a combination of views.

A flexible class is a class that declares more than

two views, its instances which must specify a

particular viewpoint take various appearances. In the

Figure 1, the "

Media_Library" class is a flexible class,

which owns 3 views ("

Loans", "Exemplaries",

Counts_Adherents").

The graphic representation of the flexible class

and the visibility relationship are illustrated

respectively by the "flexible" stereotype added to the

class symbol of UML and the stereotype "

seen_as"

added to the inheritance relationship symbol of

UML (Figure 1).

The syntax proposed by VBOOL to declare

views is the following:

flexible class Media_Library

feature...

-- declaration of views

seen_as Loans

seen_as Exemplaries

seen_as Counts_Adherents

.....

end class -- Media_Library

In a flexible class the definition of new features

implies specification of their export status. Some

features can be exported to some client’s classes,

other should be used only by specific instances with

particular viewpoint on the flexible class. This

Loans

Counts_

Adherents

Figure 1: Visibility relationship and flexible class

Exemplaries

<< seen_as>>

<<seen_as>>

<<seen as>>

<<flexible>>

Media_Library

ICEIS 2004 - INFORMATION SYSTEMS ANALYSIS AND SPECIFICATION

218

restriction of visibility is expressed by the

view_feature" keyword.

flexible class Media_Library

feature...

-- Views declaration

...

-- View feature declaration

view_feature Loans, Exemplaries,

Counts_Adherents

display do ... end

...

end class -- Media_Library

Instances of a flexible class are defined by

specifying a viewpoint as follows:

Media_library_librarian: Media_Library (Loans,

Exemplaries,

Counts_Adherents);

The "Media_library_librarian" is an instance of

Media_Library" having the viewpoint (Loans,

Exemplaries,

Counts _Adherents). Features declared in

"Loans", in "Exemplaries" and in "

Counts

_Adherents

" classes and those specified in

view_feature Loans, Exemplaries, Counts _Adherents"

or in "feature" clauses of "

Media_Library" class are

accessible by "

Media_library_librarian" instance .

The object to use the viewpoint is to define

access rights to the model. If we consider librarian's

access for example the views "Loans",

"Exemplaries" and "

Counts_Adherents" concern him.

Contrary to the person in charge of members, the

librarian must not have the right to change the

adherent's feature “

block_count_adherent”, so to call

this feature of the "

Counts_Adherents" view. To solve

this problem, the “mutual exclusive views” concept

has been introduced, that means to specify the views

that cannot be simultaneously in the same viewpoint.

Thus, in the Media library Management example, we

can create two views inheriting from

Counts_Adherents": the views

Mod_Counts_Adherents" and "Not_Mod_

Counts_Adherents

". These two views are in mutual

exclusive (Figure 2): that is to say

Mod_Counts_Adherents" view that will have access

the person in charge of exemplaries and

Not_Mod_Counts_Adherents" view that will have

access the librarian. Of the same way, the librarian

must not have the right to change the

“

number_available_exemplary” feature of a

"Exemplaries" view, contrary to the person in

charge of exemplaries who can add new exemplary

or to withdraw the damaged exemplaries by

invocation the two features “

add_exemplary” or

“

withdraw_exemplary” of the "Exemplaries" view.

Thus, we can also create two views inheriting from

"Exemplaries", "

Mod_Exemplaries" view that will

have access the person in charge of exemplaries

and "

Not_Mod_Exemplaries" view that will have

access the librarian (Figure 2).

VBOOL propose others concepts such as:

- visibility derivation which enables a class to

see a flexible class upon a particular

viewpoint,

- viewpoint evolution, polymorphism.. etc.

3 STAGES OF U_VBOOM

METHOD

VBOOM is a method of analyze/design, which

integrates the multiview approach in a coherent and

deductive method (Coulette, 1996) (Kriouile, 1995) .

VBOOM provides users the possibility to:

- deal strategically with problem space by

identifying user's needs,

- improve the interaction expert/user and

designer,

Counts_Adherents

Exemplaries

ure 2: Exam

le of mutual exclusive views

<<seen as>> <<seen as>>

<<seen as>>

Not_Mod_

Counts _Adherents

Loans

Mod_

Exemplaries

Mod_ Counts

_Adherents

Not_Mod _

Exemplaries

{exclusive views} {exclusive views}

<<seen as>>

<<flexible>>

Media_Library

U_VBOOM : UNIFIED ANALYSIS AND DESIGN PROCESS BASED ON THE VIEWPOINT CONCEPT

219

- establish partials models, operating different

knowledge of the system. Those models,

which make design easier, are called

"model's view". Each one concern a specific

viewpoint,

- generate a unique model integrating

different view models.

Like has been made for the OMT (Rumbaugh,

1989), OOSE (Jacobson, 1992), BOOCH (Booch,

1994) methods, the VBOOM method must take in

account the standard UML, i.e. to integrate the

concepts and the notations used in the unified

modeling language in the VBOOM method, by

using its possibilities of specialization and extension

(notably the stereotypes) (Hair, 2001) (Hair, 2002).

The

U_VBOOM method presents an adaptation of

VBOOM to UML. The development model of

U_VBOOM is iterative, incremental, and piloted by

the use case of UML (Jacobson, 1992) (Jacobson,

1993).

U_VBOOM is an adaptation of VBOOM to

UML,

U_VBOOM method proposes two kinds of

models: static and dynamic one to describe the

system and its behaviors. The establishment of those

models is an incremental process of 3 stages. The

first stage consists of defining model components,

the second one enables designer to develop their

commonly or not, The final stage has the goal to

generate a coherent document (global model,

dictionary of components, scenarios).

3.1 Stage1: global analysis

The object of the first stage is to define model

components. It is a stage of global specification of

development by U_VBOOM. It consists in

providing a precise description of the different needs

of the system users.

To express the users needs through the system,

U_VBOOM proposes the use cases of UML (Figure

3). The views elaboration of the system is supported

by the use cases description technique in actions

(Hair, 2001) (Hair, 2002). This technique consists to

describe the use case as an action sequence that will

make an actor to achieve his goal. An action is an

effect produced by an actor acting in way given on

the system or by the system itself (Dano, 1997).

Every action has a number and a label who are

indicated in the “Decomposition in actions” column

(Table 1).

The use cases identified for the actors and the

intersection of their actions are going to permit to

cut the viewpoints in views. A view corresponds to

actions list to a given viewpoint or result of actions

intersection of viewpoints group (Figure 4).

ure 3: Use case dia

ram of MEDIA LIBRARY s

ste

Person in

charge of

adherents

New member

litigation

Identification member

reservation

restitution

Loans

Librarian

uses uses

uses

Exten

Loan if count blocked

Exemplary

withdrawal

Exemplary addition

Person in

charge of

exem

laries

Figure 4: Viewpoint diagrams of the MEDIA LIBRARY system

<<viewpoint >>

Management of Loans

<< viewpoint>>

Management of Members

<< viewpoint>>

Management of Exemplaries

Counts_Adherents =V1={ a1, a2, a7 }

Exemplaries=V2 ={ a3, a8, a9}

Loans =V3={ a4, a5, a6}

V1 V2

ICEIS 2004 - INFORMATION SYSTEMS ANALYSIS AND SPECIFICATION

220

Table 1: Decomposition of the different use cases in actions

Actors Use case Decomposition in actions

Loan

a1: To identify an adherent

a2: Count adherent (To check right loan for member)

a3: To seek for an exemplary

a4: To treat an exemplary (to validate the output of an exemplary)

a5: To treat adherent (to indicate the loan by adherent)

Reservation

a1: To identify an adherent

a2: Count adherent (To check right loan for member)

a3: To seek for an exemplary

a6: To reserve an exemplary

Restitution

a1: To identify adherent

a3: To seek for an exemplary

a4: To treat an exemplary (to validate the input of exemplary )

a5: To treat adherent (to indicate the return of an exemplary)

Loan if counts blocked a1: To identify adherent

a2: Count adherent (To check right loan for member)

Librarian

Identification member a1: To identify adherent

New adherent a 2: Adherent account (to Add adherent) Person in

charge of

adherents

Litigation

a1: To identify adherent

a2: Count adherent (Blocked count adherent)

a7: To inform adherent

Exemplary addition a3: To seek for an exemplary

a8: To add copy

Person in

charge of

exemplaries

Exemplary withdrawal a3: To seek exemplary

a9: To withdraw the damage exemplary

The global analysis stage continues to identify

objects and classes belong to the with problem

domain. The classes are discovered, scenarios after

scenarios, by means of objects who, in collaborating,

achieve use cases. It leads to the development of the

class diagrams (Figure 5) and the object diagrams.

Finally, the packages can be identified to

organize the modeling elements. The identified

packages are gotten by according to the logical

criteria use type of an actor. These packages are

going to become thereafter the sub-system (named

model’s view) during the second stage of the

U_VBOOM method (Figure 6).

The classes constituting a package represent a

part of class diagram of the system. This part is

defined in respecting the following rules:

- the only views (classes) of the package are

those of its associated viewpoint,

- the classes joined by the customer

relationship to one of the package classes,

- the classes jointed by inheritance of each

package classes.

3.2 Stage2: The sub-systems design

The global analysis of the U_VBOOM method is

elaborated and it will be enriched in second stage.

The design of sub-systems (packages identified in

the global analysis stage, named model’s view)

permits the translation of the analysis model. These

sub-systems constitute an essential artifact of the

second stage of the U_VBOOM method. Indeed, the

cutting out the solution space of the problem in sub-

systems permits to land the global system design to

sub-systems designs. The design of sub-systems can

be made in a disparate and autonomous way and be

led in parallel or sequential.

The second stage of U_VBOOM has for object

to achieve the partials class diagrams and to define

the partials classes interfaces of every sub-systems

(the class interface contains the list of its features).

The designer must come back toward to realize the

use cases. The scenarios, the collaborations between

analysis objects and the class diagrams are refined to

get the design classes constituting the partial

dictionary of every sub-system. The Figure 7

represents the class diagram (partial) of the

Management of Loans sub-system.

U_VBOOM : UNIFIED ANALYSIS AND DESIGN PROCESS BASED ON THE VIEWPOINT CONCEPT

221

<<model’view >>

Management of Loans

<<model’s view>>

Management of Exemplaries

<<model’s view>>

Management of Members

Figure 6: The 3 packages of the MEDIA LIBRARY system

{

exclusive views

}

{

exclusive views}

Works

LocateIn

BePublishedIn

Emplacement

Counts _Adherents

Author

Support

AudioCD

VideoCassette

AudioCassette

SaveIn

Book

Exemplary

Not_Mod_

Counts _Adherents

Mod_ Counts

_Adherents

Loans

<<flexible>>

Media_Library

Exemplaries

Mod_

Exemplaries

Not_Mod _

Exemplaries

<<seen as>>

<<seen as>> <<seen as>> <<seen as>>

Figure 5: Initial class diagram of the MEDIA LIBRARY system

<<seen as>>

VideoCassette

Book

Timer

ure 7: Class dia

ram of the Mana

ement of Loans sub-s

ste

Write

Works

Author

Variety Opera Film Work

AudioCD AudioCassette

Support

Adherent

BePublishedIn

LocateIn

Emplacement

Loan

Mod_ Exemplaries

Not_Mod_

Counts_Adherents

Exemplary

Loans

Counts_Adherents

Exemplaries

SaveIn

<<flexible>>

Media_Library

ICEIS 2004 - INFORMATION SYSTEMS ANALYSIS AND SPECIFICATION

222

3.3 Stage3: Global model design

The third stage of the U_VBOOM method provides

to the process designers to melt the differents

partials class diagrams and the differents partials

class interfaces of the sub-systems obtained from the

second stage of the method. The melting process

proposes to the designers the heuristic to manage the

conflicts appeared during of this stage (polysemies,

synonymies, homonymies...) (Figure 8). In our

example, the global model is relatively close to the

Management of Loans sub-system because this last

is predominant in the system, but this situation is not

evidently a generality. The sub-systems obtained are

tested and validated in order to be coded in the

implementation activity.

4 CONCLUSION

The representation of relationship visibility of

VBOOM in UML encouraged the integration of

UML in VBOOM. The U_VBOOM method that

represents the result of VBOOM adaptation under

the UML standard is incremental, iterative and

piloted by the use cases.

The decomposition of the system in packages,

which became the sub-system, by the logical cutting

based on use type permitted to land the global

system design to the sub-systems designs.

The work describes herein is part of a project

which define a methodology of development of

components multiview objects. Among the tasks

remaining to achieve in this project, we can mention:

- the definition of the composing multi-

views notion as regrouping of multiview

classes,

- the development of a basis of design

pattern supporting the viewpoints

approach,

- the realization of an environment

support of U_VBOOM.

Figure 8: Class diagram of the MEDIA LIBRARY system

Variety Opera Film

Interpreted_Work

Not_Interpreted

_Work

Work

Write

Works

Author

AudioCD

Book

AudioCassette

VideoCassette

support

Timer

Mod_Counts

_Adherents

Adherent

LocateTo

Emplacement

Loans

Not_Mod_

Counts_Adherents

Exemplaries

Counts_Adherents

BePublishedIn

Exemplary

Loan

Not_Mod_

Exemplaries

SaveIn

Mod_

Exemplaries

{ exclusive views}

<<seen as>>

{ exclusive views}

<<seen as>>

<<flexible>>

Media_Library

<<seen as>>

U_VBOOM : UNIFIED ANALYSIS AND DESIGN PROCESS BASED ON THE VIEWPOINT CONCEPT

223

REFERENCES

Booch, G., 1994. Object-Oriented Analysis and Design

with Applications. Benjamin/Cummings, Redwood

City.

Carré, B. 1991. The Point of View notion for Multiple

Inheritance. In ECOOP/OOPSLA’91.

[Coulette, B., 1996. L’approche par points de vue dans le

développement orientée objet de systèmes complexes.

Revue l’Objet, Vol. 10, No. 5, pp. 13-20.

Dano, B., 1997. An Approach Based on the Concept of

Use Cases to Produce Dynamic Object Oriented

Specifications. In the Third IEEE International

Symposium on Requirements Engineering.

Finkelstein, A., 1993. Inconsistency Handling in Multi-

Perspective Specifications. In ESEC'93, Garmish-

Paternkirchen , pp. 84-99.

Hair, A., 2001. VUML : Une méthode d'analyse et de

conception orientée objet, intégrant UML et le concept

de point de vue. In ICSSEA'2001, the International

Conference on Systems, Software Engineering and

their applications.

Hair, A., 2002. Un processus d'analyse et de conception

unifié basé sur le concept de point de vue. In CARI'02,

Africain Conference on Research in Computer

Science, pp. 229-237.

Jacobson, I., 1992. Object-Oriented Software Engineering,

A Use Case Driven Approach. Addison-Wesley, Inc..

Jacobson, I., 1993. The Unified Software Development

Process. Addison-Wesley, Inc..

Harrison, W., 1993. Subject-oriented programming: a

critique of pure objects. In OOPSLA’93, Washington

D.C., pp. 411-428.

Kriouile, A., 1995. VBOOM, une méthode d’analyse et de

conception par objet fondée sur les points de vue.

Ph.D. thesis of sciences faculty, Rabat.

Krutchen, P., 2000. The Rational Unified Process - An

Introduction. Addison-Wesley, Inc..

Lopez, N., 1998. Intégrer UML dans vos projets. Edition

Eyrolles.

Marcaillou, S., 1995. Intégration de la notion de points de

vue dans la modélisation par objets ; Le langage

VBOOL. Ph. D. Thesis of Paul Sabatier university,

Toulouse.

Mili, H., 1999. View programming of OO applications. In

TOOLS’99, 1999.

Meyer, B., 1995. Object success - A managers’s guide.

Prentice Hall - The Object-Oriented Series.

OMG, 2001. Unified Modeling Language (UML), version

1.4, Document formal/2001-09-07,

http://www.omg.org/cgi-bin/doc?formal/01-09-67,

Rumbaugh, J., 1989. The Unified Modeling Language

Reference Manual. Addison-Wesley.

Rumbaugh, J., 1989. OMT : Modélisation et conception

orientées objet. Prentice Hall.

Shilling, J., 1989. Three Steps to Views. In OOPSLA’89,

New Orleans, LA, pp. 353-361.

ICEIS 2004 - INFORMATION SYSTEMS ANALYSIS AND SPECIFICATION

224