Modeling the goal argumentation method By A. J. Jansen.

Modeling the goal argumentation methodBy A. J. Jansen

Introduction

Goal Argumentation Method For justifying goal modeling decisions

Definition of GAM: A method to model the arguments and choices made

in the Requirement Engineering processes for Information Systems.

Purpose of GAM:- To prevent loss of modeling reasons over time or in big

projects- To provide a structured form for the reasoning proces in

requirement engineering

AuthorsIvan J. JuretaPHD University of NamurResearch focus on method engineering and automation 222 citations on Microsoft Academic Search

Stépahn FaulknerAssociate Professor at the University of NamurResearch focus on Technologies and Information Systems Engineering338 citations on Microsoft Academic Search

Pierre-Yves Schobbens Professor at the University of NamurResearch focus on on requirement engineering and model driven engineering847 citations on Microsoft Academic Search

The Goal Argumentation Method

Problem Statement

Alternatives

Alternative Justification

Diagram Change

Problem analysis

Evaluation

DecissionProblem Setting

Related Literature 1/2 Curtis B. (1988) Conclusion: Lack of documentation of

RE arguments is a large cause for project failure. Castroa J. K. M. (2002) provided a widely accepted

method in RE: the Tropos Method Lourdas P.,(2000) provided a reasoning loop model Chesñevar C.I. (2000) provided a way to abstract the

arguments to a logical model Dardenne A. (1993) provided a way to convert these

abstracted arguments to code

Related Literature 2/2

Pohl (1994) states that a RE method should have at least three dimensions: the specification dimension the representation dimension the argumentation dimension

Related methods CobiT (Martínez M., 2010) and the KAOS method (Darimont R., 1997)

GAM Versions Light Modus Normal Modus Advanced Modus

PDD

Diagram change

Evaluate

Problem setting

Accept justified alternative

Add alternatives to the dialectial tree

[More undefeated trees exist]

[else]

[more problems occured during the

process]

[else]

I-STAR STRATEGIC RELATION DIAGRAM

ALTERNATIVE

PROBLEM STATEMENT

INTERMEDIARY LANGUAGE CODE

OUTPUT generates

DIALECTICAL TREE MAP

Set Problem

DIALECTICAL TREE

LABEL

ARGUMENT

DescriptionSupport value

solves

11

1..*

1

1

1..*

1

1..*

1

1

1

1

1

Write intermediary language code for the undefeated tree

JUSTIFIED DIALECTICALTREE

results in

1

Generate the associated I-Star SR diagram

Add arguments to the dialectical tree

Label the dialectical trees

Is rewritten to

1

Create a dialectical tree for the problem statement

1..*

UNDEFEATEDDEFEATED

c

SITUATIONAL PROBLEM CASE

1

0..*

based on

Stakeholder

Stakeholder

Stakeholder

Stakeholder

Stakeholder

REQUIREMENT1 1..*

Values1..*

1

GAM

ExampleA professor wants to build a service, in which he offers the lectures, that he and his department give, online. This is in case students are “ill” and through this have to miss a lecture. However, this should not cost too much, since budget cuts also hit the university…

GAM Light: Decission Process

1.Alt1: Film lectures. 1.Alt2: Audio record lectures.

1.Alt1Arg1+: Good quality lectures for students.

1.Alt1Arg2-: Relatively expensive equipement needed.

1.Alt1Arg3-: Difficult to arrange due bureaucracy at University.

1.Alt2Arg1-: Less quality but together with slides it is sufficient.

1.Alt2Arg2+: Audio device is relatively cheap.

1.Alt2Arg3+: Audio device is easy to acquire.

1.Alt2Arg4+: Some lecturers already has positive experience with audio devices.

1.Just2: Alt2 is preferred to Alt 1 by the stakeholders, because they consider it to require less effort and less budget.

PS2: Which audio device should be acquired?

PS3: The use of the device should be promoted.

PS6: Shouldn’t there be a budget estimate that would take into account user friendliness and effort in use?

…

…

…

PS1: Sick students should be able to view lectures in a cost effective way online.

1.Alt2Arg5+: Audio is easier to put online.

1.Alt2Arg6+: Audio recording requires little skill.

PS5: Lectures should acquire skills on how to record audio.

…

PS4: Web space should be available for the audio recordings …

Dialectical Tree Map

GAM Normal: Dialectical Tree Map

aquire_audiorecording_skills(lecturer)

easy_to_put_online(lecturer)

post_on_website(lecturer)

slides(lecturer)

provide_course_with_audio(lecturer)

audiorecording(lecturer)

< T2, provide_course_with_audio(lecturer) >

U

<T1, provide_course_with_film(lecturer)>

D

provide_course_with_film(lecturer)

post_on_website(lecturer)

cheap_to_use(lecturer)

easy_to_aquire(lecturer)

easy_to_aquire(lecturer)

filmrecording(lecturer)

easy_to_put_online(lecturer)

¬cheap_to_use(lecturer)¬easy_to_aquire(lecturer)

GAM Advanced: Advanced Dialectical tree

do(aquire_audiorecording_skills(lecturer))

optimize(easy_to_put_online(lecturer))

do(post_on_website(lecturer))

provide(slides(lecturer))

depend(student, provide_course_with_audio(lecturer))

provide(audiorecording(lecturer))

optimize(cheap_to_use(lecturer))

optimize(easy_to_aquire(lecturer))

optimize(easy_to_aquire(lecturer))

Conversion

GAM-Tropos Translation Rules Examples

task(aquire audiorecording skills)do(aquire_audiorecording_skills(lecturer)

Acquire skills on how to record audio

provide(slides(lecturer)) resource(slides) slides

Labeled well-formed formulas in a dialectical tree

Intermediary language Element in a Tropos Goal Diagram

+

 Lecturer

Provide audio online

Post on website

 Student

  Cheap to use  

Acquire skills on how to record audio

Course website 

Slides

Record Audio

Audio records 

+

easy to aquire

provide slides online

+

Tropos RE Diagram

Questions

References Curtis B., K. H. (1988). A Field Study of the Software Design Process for

Large Systems. Communications of the ACM, 1268-1287. Castroa J., K. M. (2002). Towards Requirement-Driven Information

Systemens Engineering: The Tropos Project. Information Systems 27, 365-389.

Chesñevar C.I., M. A. (2000). Logical Models of Arguments. ACM Computer Serveys 32, 32-41.

Dardenne A, v. L. (1993). Goal-directed requirements acquisition. Science of Computer Programming volume 20, 3-50.

Darimont R., D. E. (1997). GRAIL/KAOS: An Environment for Goal Driven Requirement Engineering. ICSE '97 Proceedings of the 19th international conference on Software engineering (pp. 612-613). New York: ACM Inc.

Lourdas P., a. L. (2000). A Generic Model for Reflective Design. ACM Transactions on Software Engineering and Methodology, Vol. 9, 199-237.

Martínez M., L. J.-M. (2010). A Personal Data Audit Method through Requirements Engineering. Computer Standards & Interfaces, 166–178.