adaptation of evolving requirements : a managed approach for non-functional requirements tanya...
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Adaptation of Evolving Requirements : A Managed
approach for Non-functional requirements
Tanya Kudchadker
Nivedita Angadi
Guides:
Dr. A. Serebrenik (TU/e)
Martijn Klabbers, ir(LaQuSo)
Requirements Management - Steps
• Requirement Elicitation
• Requirement Analysis
• Requirement Specification
• Requirement Validation
/ SET Seminar PAGE 212/02/2009
Introduction Evolution Current Approach NFR Research
GoalCurrent Work Further Tasks Summary References
Requirements Evolution
• Royce 1970, “Waterfall model”.− What is requirements
evolution?
In which stage does requirements
evolution begin?
/ SET Seminar PAGE 312/02/2009
Introduction Evolution Current Approach NFR Research
GoalCurrent Work
Further Tasks Summary References
Requirements Evolution Cycle
/ SET Seminar PAGE 412/02/2009
Introduction Evolution Current Approach NFR Research
GoalCurrent Work
Further Tasks Summary References
Driving factors for Requirements Evolution
• Users need change
• Changes in the environment
• Adoption of new technologies
• Co-operative computing
/ SET Seminar PAGE 512/02/2009
Introduction Evolution Current Approach NFR Research
GoalCurrent Work
Further Tasks Summary References
Is the requirement acceptable?
/ SET Seminar PAGE 612/02/2009
Change Management
• Process to implement changes in the system.
• Changes need to be formally introduced and approved.
• Request For Change(RFC) form
/ SET Seminar PAGE 712/02/2009
Introduction Evolution Current Approach NFR Research Goal
Current Work
Further Tasks Summary References
Change management
/ SET Seminar PAGE 812/02/2009
Non functional requirements
• Why are non-functional requirements(NFR) important?
• NFRs are often neglected or forgotten.
• Ineffectively dealing with NFRs can lead to a series of failures in software development.
/ SET Seminar PAGE 912/02/2009
Introduction Evolution Current Approach NFR Research Goal
Current Work
Further Tasks Summary References
The need of the hour
• A methodical process to assess the consequences of the requirement change.
• Emphasis on Non-functional requirements.
• Practical guidelines to accept or reject the proposed change.
/ SET Seminar PAGE 1012/02/2009
Introduction Evolution Current Approach NFR Research Goal Current Work
Further Tasks Summary References
Types of changes
/ SET Seminar PAGE 1112/02/2009
Introduction Evolution Current Approach NFR Research Goal Current Work Further
Tasks Summary References
Process Model
• Sequence of steps for handling new or changing requirements during life time of a system.
/ SET Seminar PAGE 1212/02/2009
Requirement Change
Identify change
Introduction Evolution Current Approach NFR Research Goal Current Work Further
Tasks Summary References
Environment Change
• Identify change in the environment
• Analyze the change for its effects.
/ SET Seminar PAGE 1312/02/2009
Introduction Evolution Current Approach NFR Research Goal Current Work Further
Tasks Summary References
Requirement Change
• Identify the possible requirement change to the existing system.
/ SET Seminar PAGE 1412/02/2009
Introduction Evolution Current Approach NFR Research Goal Current Work Further
Tasks Summary References
Impact Analysis
• Impact of requirement changes on• Non-functional requirements associated with the
proposed change.• Viewpoints of each stakeholder.
/ SET Seminar PAGE 1512/02/2009
Introduction Evolution Current Approach NFR Research Goal Current Work Further
Tasks Summary References
Design Change
• Identify implications to the existing design of the system.
/ SET Seminar PAGE 1612/02/2009
Introduction Evolution Current Approach NFR Research Goal Current Work Further
Tasks Summary References
Further tasks
• Refinement of the process model.• Application of the model on a case study and identify
the various non-functional requirements which led to its failure.• E.g. London Ambulance Service Computerised Despatch
System(LASCDS)
12/02/2009 PAGE 17/ SET Seminar
Introduction Evolution Current Approach NFR Research Goal Current Work Further Tasks Summary References
Summary
• Requirements evolution is a continuous process.
• Various factors drive the initiation of requirements evolution.
• Acceptance of these changes is a critical task.
• Non functional requirements play a big role in system ‘well-being’.
• A practical method/guidelines is a necessary for decision over acceptance of such changes.
12/02/2009 PAGE 18/ SET Seminar
Introduction Evolution Current Approach NFR Research Goal
Current Work
Further Tasks Summary References
References
• Nazim H. Madhavji Juan Fernandez-Ramil, and Dewayne Perry: Software Evolution and Feedback: Theory and Practice. John Wiley & Sons, 2006.
• Lam, W., Loomes, M.: Requirements Evolution in the Midst of Environmental Change: A Managed Approach, IEEE Computer Society, 1998
• Cysneiros L.M., Leite J.C.S.P.: Nonfunctional Requirements: From Elicitation to Conceptual Models. IEEE Transaction in Software Engineering, 30(5):328–350, May 2004
12/02/2009 PAGE 19/ SET Seminar
Introduction Evolution Current Approach NFR Research
Goal Current Work Further Tasks Summary References
Questions?
12/02/2009 PAGE 20/ SET Seminar
12/02/2009 PAGE 21/ SET Seminar