Towards Integrated Tool Support for the User Requirements Notation

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Towards Integrated Tool Support for the User
Requirements Notation

• Jean-François Roy (jroy_at_site.uottawa.ca)
• Jason Kealey
• Daniel Amyot
• SITE, University of Ottawa

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Outline

• Context
• Metamodel
• jUCMNav
• Integrating UCM and GRL
• Model Analysis Capabilities
• Future Work
• Demo

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User Requirement Notation (URN)

• URN combines two views
• Use Case Maps (UCM) operational scenarios over
  architectural components
• Goal Requirements Language (GRL) modeling goals,
  requirements, alternatives and rationales.
• URN language requirements defined in Z.150

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Notations in isolation

• Tool support for each view in isolation
• UCMNav Supports UCM notation, but has usability
  and maintainability issues
• OpenOME Supports multiple goal/agent notations
  including GRL
• No integrated solution for complete URN models

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Motivation

• Develop a tool that supports both views
• Integrate these views by linking elements
• Provide model analysis features
• Support reusability of models

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Metamodel Structure

• 2 metamodels abstract and implementation
• 4 main packages URN, URNcore, GRL, UCM
• URNcore package defines basic concept for both
  notations
• URN package defines links between UCM and GRL

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Abstract Metamodel
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From Abstract to Implementation

• Add visual elements
• Attributes - position (x, y)
• - size (height, width)
• - color
• -
• Classes - links routing
• Abstract elements common to both UCM and GRL
• - graphs
• - nodes
• - links
• - containers
• - container references

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Implementation Metamodel
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UCM Implementation Metamodel
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jUCMNav

• Eclipse plug-in
• Open-source application available under the
  Eclipse Public License (EPL)
• Uses the Eclipse Modeling Framework (EMF) and the
  Graphical Modeling Framework (GEF)
• First developed as a replacement for UCMNav
• User interface follows Eclipse standards

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jUCMNav

• Basic Editing Features
• jUCMNav takes advantage of the Eclipse views
  (hierarchical/graphical outline, properties,
  resources)
• Improved usability drag drop editing, group
  manipulation, unlimited undo/redo,
• Multiple element references
• Autolayout mechanism
• Only allows the creation of syntactically valid
  models

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Reusability GRL Catalogues

• Export GRL definitions for reuse in other models
• Catalogue
• Catalogue name, Description, Author
• Intentional Element
• Id, Name, Description, Type, Decomposition Type
• Decomposition
• Name, Description, Source id, Destination id
• Contribution
• Name, Description, Source id, Destination id,
  Contribution type, Correlation
• Dependency
• Name, Description, Dependee id, Depender id

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Integrating UCM and GRL

• Provides traceability links between elements of
  both notations
• Used during model analysis
• Improved consistency between views

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Supported URN Links

• Intentional Elements ? Responsibilities
• Intentional Elements ? Components
• Intentional Elements ? Maps
• Actors ? Components
• Actors ? Responsibilities
• Actors ? Maps
• Others to come

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GRL Strategies

• User defined sets of initial evaluations
• Evaluation propagated in the model
• Implemented using the strategies view
• Numerical interpretation of the satisfaction
  levels
• Evaluation of the impact of strategies on the
  operational and architectural aspects, using URN
  links

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Numerical Evaluation

• Evaluation between -100 and 100.
• E -100 -gt Denied
• -100 lt E lt 0 -gt Weakly Denied
• E 0 -gt Undecided
• 0 lt E lt 100 -gt Weakly Satisficed
• 100 -gt Satisficed

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Propagation Algorithm

• Developed a new propagation algorithm for
  numerical evaluations
• Supports automatic conflict resolution
• Uses all link types to calculate the evaluation
• Decompositions, Contributions and Dependencies.

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Decompositions

• Calculated as a standard And/Or graph

And Decomposition
Or Decomposition
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Contributions

• Suppose E, the evaluation value of an intentional
  element after the decomposition calculation with
  N contributions.
• For each contribution, convert the contribution
  level to the corresponding factor (LEV)
• Make 1
• Help 0.5
• Some Positive 0.25
• Unknown 0
• Some Negative -0.25
• Hurt -0.5
• Break -1

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Contributions

• Normalize non-zero source element evaluations for
  each contribution to a value between 0 and 100 (0
  for denied, 100 for satisficed) NEVAL
• Calculate the Total Contribution value (TCON)
• If (TCON gt 100) TCON 99
• Else If (TCON lt -100) TCON -99
• Calculate the target evaluation by adding TCON to
  evaluation E.

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Examples
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Dependencies

• Intentional element evaluation is set to the
  minimal value in the set of dependees evaluation
  or it current evaluation

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Algorithm Implementation

• Strategy design pattern. Using Eclipse
  extension points, new algorithms can be added
  easily.
• public void init(EvaluationStrategy strategy,
  HashMap evaluations)
• public boolean hasNextNode()
• public IntentionalElement nextNode()
• public int getEvaluation(IntentionalElement
  element)

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Actor Evaluation

• New evaluation to deal with negotiation between
  stakeholders.
• Helps analyzing and comparing the satisfaction
  levels of each actor based on the selected
  strategy
• Computed from priority and criticality of
  intentional element references bound to actors

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Actor Evaluation Example
Priority Low Criticality None
Priority None Criticality High
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jUCMNav Extensibility
jUCMNav plugin to export/synchronize URN models
to/with Telelogic DOORS
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Future Work

• Add missing UCM notation elements
• Extend jUCMNav to support scenario definitions
• Export to Core Scenario Model format for
  performance modeling
• Add a simple data model compatible with SDL
• Add other analysis capabilities to measure the
  impact of strategic decisions on the scenario and
  architectural aspects of the model
• Work on further URN links and improve the
  modeling and analysis process based on those
  links
• Develop further analysis algorithms for the GRL
  strategies.

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Demo
http//jucmnav.softwareengineering.ca