????,????%20Long%20union%20must%20separate,%20long%20separation%20must%20unite%20%20Discovering%20aspects%20from%20requirements%20goal%20models

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????,????Long union must separate, long
separation must unite Discovering aspects from
requirements goal models

• Yijun Yu1Julio C. S. P. Leite2
• John Mylopoulos1

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Identify Aspects Early on in the Software
Development Process

• Our Goal

Our Result
Aspects can be discovered during goal oriented
requirements analysis
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Overview

• Early Requirements in AOP paradigm
• 1.1 Design Principles in AOP
• 1.2 Requirements Goal Models
• Aspect discovery through construction of a
  V-graph (goals, softgoals, and tasks)
• A case study Media ShoposCommerce
• Summary

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1. Principles1.1 Increase Fan-in, aka. DRY

• Whenever possible, we wish to maximize fan-in
  during the design process. Fan-in is the raison
  dêtre (grounds for existence) of modularity.
  Each instance of multiple fan-in means that some
  duplicate code has been avoided. (Yourdon,
  Constantine, Structured Design p. 172, 1979)
• The DRY principle Dont Repeat YourselfA.
  Hunt, and D. Thomas. Pragmatic Programmer.
  Addison Wesley,1999. in (Martin Fowler, Avoid
  Repetition, IEEE Software, Jan/Feb 2001
  pp.9799.)

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DRY
IOC
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MOVE UNTIL
VALUE
FIND
REMOVALL
STRINGCOMP
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Stan Wagons bike

• My square-wheel bike, on permanent display at
  Macalester College. This construction, believe it
  or not, earned me an entry in "Ripley's Believe
  It or Not" beats standing in a block of ice for
  three days or growing three-foot long
  fingernails.
• -- http//www.stanwagon.com
• Stan Wagon (wagon_at_macalester.edu), Prof. of
  Mathematics and Computer Science, Macalester
  College, St. Paul, Minnesota

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AspectJ
The DRIVER
aspect
aspect Logging pointcut NeedLogging()
call(void FIND()) call(void
MOVEUNTIL()) call(void REMOVALL)
call(void SCAN() call(void
VALUE()) after() returning NeedLogging()
STRINGCOMP()
The GROUND
The WAGON
advice
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1.2 Requirements Goal Models

• A goal model is an intentional model
• A goal can be decomposed into AND or OR subgoals
• A goal model has both hard and soft goals
• A hard goal can be either satisfied or denied
• A soft goal is partially satisfied gt satisficed
• Soft goal uses HELP (), HURT (-), MAKE () or
  BREAK (--) correlations to show partial
  satisfaction (satisfice) from a set of subgoals

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1.2.1 Hard goal model
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1.2.2 Soft goal model
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Goal-Oriented Requirements Analysis
FS Fully satisfied PS Partially satisfied UN
UnknownPD Partially denied FD Fully denied CF
Conflict
T satisfied F denied U unknown
CF
Get Reliable Reply
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FS Fully satisficed PS Partially satisficed UN
UnknownPD Partially denied FD Fully denied CF
Conflict
T satisfied F denied U unknown
FS
Get Reliable Reply
MAKE
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V-graph

• In order to reason about interplay of functional
  and non-functional requirements, we create a
  particular type of goal model, called V-graph

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V
correlation
Softgoal
contribution
contribution
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2. The Process

• Start from root-level goals and soft goals,
  correlate and decompose them into a V-graph
• A goal analysis based on the label propagation
  algorithm is used to check for
• Conflicts
• Inconsistencies
• Denial of any goal or soft goals
• After resolving the problems, a proper V-graph is
  obtained
• Then we list the candidate aspects from the
  V-graph

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list objectives
root goal
softgoals
softgoals
softgoals
softgoals
goals
?
No
tasks
Yes
No conflict
No
?
Yes
No
?
Consistent
Yes
Satisfied satisficed
V model
softgoals
goals
tasks
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3. A Case Study

• Medi_at_Shop adapted from literature
• Castro, Kolp, Mylopoulos, Towards
  requirements-driven information systems
  engineering the Tropos project, Journal of
  Information Systems, 2002. Can we find aspects
  from early requirements?
• osCommerce studied from an LAMP (Linux, Apache,
  MySQL, PHP) Open-Source project
  (http//www.oscommerce.com) Do they manifest in
  the developed software?

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osCommerce (version 2.2m2)
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Candidate aspects in the codeClone detection (by
Semantic Design,Inc)
LOC clones Code description Need refactoring?
1 319 require(path . file) No
1 260 echo expression No
559 2 class email No
2 292 define (variable, value) No
76 2 class mime No
4 67 messageStack-gtadd (error) Yes (NFR)
15 15 Postal code zone check Yes (FR)
22 10 require(application_top.php)SSL check Yes (FR/NFR)
3 64 Set HTML head CHARSET Yes (NFR)
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list objectives
root goal
softgoals
softgoals
softgoals
softgoals
goals
?
No
tasks
Yes
No conflict
No
?
Yes
No
?
Consistent
Yes
Satisfied satisficed
V model
softgoals
goals
tasks
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Correlate initial goals and softgoals
T1
T0
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Inconsistent decomposition
FS
FS
T
FS
FS
T1
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Resolving inconsistency
T
PS
T
FS
T
T
FS
FS
T2
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Further decomposition
T3 T4
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Further
T5
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T6
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Resolving Conflicts
T
CF
T
T
T
T
T
T6
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Result candidate aspects
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Goal Aspects

• goal aspect Responsivenesstransaction
• pointcut transaction() Preparingcart,product
  )
• CheckingOutcart, product, account,
  stock)
• required () by transaction()
• SessionCookietransaction()
• AspectJ-like syntax
• Allow weaving the operationalized tasks with
  goals specified in the pointcut

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4. SUMMARY
Separatingaspects
goals
softgoals
tasks
V graph
Goal aspects
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5. On-going and future work

• 1. On Implementations
• Weaving the goal aspects
• AspectPHP adapting the Zend PHP interpretator
• AspecT testing NFR in the weaved code
• 2. Another case study CORBA
• 3. Extensions
• From V-graph to agent-oriented frameworks such
  as i and KAOS
• reuse of goal aspects