QFD for Software Requirements Management (MSc of Software Engineering Program 2001)

1. Quality Function Deployment
QFD for Software Requirements
Management
Guy Davis
Carmen Zannier
Adam Geras

2. Quality Function Deployment
QFD for Software Requirements
Management
Guy Davis
Carmen Zannier
Adam Geras

3. Objectives
Upon completion of this chapter, students will:
Understand what Quality Function Deployment (QFD) is

Understand how QFD compares to other software

development life cycles
Be able to identify the primary QFD tools and concepts

Be able to identify the QFD practices that might be

useful in non-QFD working environments
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4. 1. Introduction to QFD
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5. 1(a) QFD - Definition
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6. 1(a) QFD – Definition (Cont.)
[ASI, 2000]
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7. 1(b) QFD - Benefits
[ASI, 2000]
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8. 1(c) QFD - History
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9. 1(d) Software Engineering Context
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10. 1(e) Requirements Engineering
Context
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11. 2. QFD Life Cycle Considerations
 QFD Process
 SQFD Process
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12. 2(a) Traditional QFD Phases
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13. 2(b) Adapting QFD to Software
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14. 2(b) SQFD Process
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15. 3. The House of Quality
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16. 3(a) Customer Requirements
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17. 3(b) Affinity and Tree
Diagrams
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18. Exercise 1 – Affinity Workshop
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19. 3(c) The Planning Matrix
 Quantifies Customer Requirements.
 Quantifies Perceptions of Existing Products.
 Allows adjustment based on design team.
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20. 3(c) The Planning Matrix
Customer Satisfaction – existing products fulfilling
specified requirements.
Improvement Ratio = Planned Performance / Existing
Performance
Sales Point – weight for marketability
Overall Weighting = Importance Weighting x
Improvement Ratio X Sales Point
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21. 3(c) The Planning Matrix
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22. 3(d) Technical
Requirements
 Engineering Characteristics, Voice of the Company.
 Identify Measurable Characteristics related to
Customer Requirements.
 Direction of change included to lead to
improvement of product performance.
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23. 3(e) Interrelationships
 Between customer requirements and technical
requirements
 Translation and correlation step
 Critical to generate consensus between
development team and customers.
Critical Question:
How significant is technical requirement A in
satisfying customer requirement B?
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24. 3(e) Interrelationships
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25. 3(f) “The Roof”
 Considers impact of technical requirements on each
other
 Feature to feature comparison
 Augment or impede?
Critical Question:
 Does improving one requirement cause a
deterioration or improvement in another
requirement?
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26. 3(f) “The Roof”
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27. 3(g) Targets
  Results from previous
Summarize previous
steps steps:
Customer requirements
 Draw conclusions 
Prioritized customer

 Consists of: requirements
Technical Priorities

Technical requirements

Competitive

Correlated requirements

Benchmarks
Feature

Final Product Targets

interdependencies
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28. 3(h) Technical Priorities
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29. 3(i) Competitive Benchmarks
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30. Target System
Meets standards
Harness weight
Webbing strength
Padding thickness
3(j) Final Product Targets
# of buckles
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31. 3(k) House of Quality Summary
 Inputs:
Customer requirements

Technical requirements

Customer priorities

Market reality / competitive analysis

Organization’s strengths & weaknesses

 Outputs
Prioritized technical requirements

Measurable, testable goals

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32. Exercise 2 – Build a House of
Quality
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33. 3(l) House of Quality Pros and
Cons
 Pros:
Generates specific technical requirements

Requirements are traceable

Follows a repeatable, quantitative process

Effectively translates Voice of the Customer

Records rationale for each technical requirement

 Cons:
Time-consuming process for >10 requirements

Data storage, manipulation and maintenance costs

Very dependent on customer requirement gathering

Inflexible to changing requirements; must recalculate

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34. 4. QFD Life Cycle Comparisons
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35. 4(a) QFD and Cleanroom
[SAIC, 2001]
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36. 4(b) QFD and SASD
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37. 4(c) QFD vs. JAD
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38. 4(d) QFD and PD
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39. 4(e) QFD vs. RAD
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40. 4(f) QFD vs. SSM
[Wilson, 2001]
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41. 4(g) QFD and RUP
[Ronin, 2001]
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42. 4(h) QFD and XP
[Wells, 2001]
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43. 5. Conclusions
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44. 5. Conclusions (Cont.)
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45. 5. Conclusions (Cont.)
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46. QFD Designer
 QFD Designer Business Improvement
Software
 Templates to define various aspects of QFD
 Icons, graphs, simplify add/delete
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47. References
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