Support for Requirement Traceability: The Tropos Case

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Support for Requirement Traceability The Tropos
Case

• Rosa Pinto, Carla Silva, Jaelson Castro

• LER Laboratório de Engenharia de Requisitos
• rccp, ctlls, jbc_at_cin.ufpe.br

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Outline

• Motivation
• Tropos framework
• Requirements traceability Meta-model
• The Requirements Traceability Process
• Case Study
• Conclusions

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Motivation
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Requirements Traceability

• Requirements traceability refers to the ability
  to describe and follow the life of a requirement,
  in both a forwards and backwards direction
  Pinheiro 2003

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Proposal
Requirement Traceability Process
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Case Study

• Media Shop is a store selling and shipping
  different kinds of media items.
• To increase market share, Media Shop has decided
  to open up a B2C retail sales front on the
  Internet.
• The system is called Medi_at_.

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Strategic Dependency Model
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Strategic Rationale Model
Medi_at_
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ArchitecturalModel
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Requirements Traceability Reference Model

• It is needed to facilitate the construction of a
  requirements traceability scheme Toranzo 2002 e
  2005
• Requirements Management sub-model
• Design sub -model
• Rational sub -model

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Requirements Management sub-model
Toranzo 2005
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Design sub-model
Toranzo 2005
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Rational Sub-Model
Toranzo 2005
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Requirements Traceability Process

• Stages of the process
• 1. Information Gathering (IG)
• IG1. System SD model
• IG2. System SR model
• IG3. Selection of architectural style
• IG4. Architectural model
• 2. Information Structuring (ST)
• Instantiating associations between classes
• Defining the set of valid values for association
  instances
• 3. Definition of the Traceability Matrixes (TM)
• Creating the appropriate traceability matrixes

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Requirements Traceability Process

• IG2. Information Gathering from Strategic
  Rationale Model
• Rule 1. Goal ? SYSTEM OBJECTIVES class
• Rule 2. Task ? REQUIREMENT class
• Rule 3. Softgoal ? REQUIREMENT class
• Rule 4. Resource ? REQUIREMENT class

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Requirement Management sub-model
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Strategic Rationale Model
Medi_at_
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Requirements Traceability Process

• IG4. Information Gathering from the Architectural
  Design Model
• Rule 1. Each architectural component ? SUBSYSTEM
  class

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Design sub-model
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ArchitecturalModel
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Requirements Traceability Process

• Stage 2. Information Structuring (ST)
• Instantiating associations between classes
• Defining the set of valid values for association
  instances

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Design sub-model
ltltRealised_Bygtgt
RB
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Requirements Traceability Process

• Stage 3. Definition of the Traceability Matrixes
  (TM)
• create a traceability matrix relating the
  instances of the REQUIREMENTS and SUBSYSTEM
  elements

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Traceability Matrix
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Contributions

• Estimating the impact of a change
• If some requirement is changed, the impact in the
  system components can be analyzed.

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Contributions

• A process to extend Tropos to address
  requirements traceability.
• Methodologies supporting requirement traceability
  can develop higher quality software with fewer
  costs

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Future Work

• We intend to develop a complete and usable
  requirement traceability process for Tropos
• Further guidelines for instantiating all the
  classes of the three reference models for each
  phase of Tropos may be required.

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Links

• Laboratório de Engenharia de Requisitos
• www.cin.ufpe.br/ler
• Tropos Project
• www.troposproject.org