1. Quality Function Deployment
Acknowledging:
David Menks
Anwar Ahmed
Kaijun Fu
Found at:

2. Other Sources on QFD/SQFD
Good overview can be found at:
Downloadable tool:
SQFD paper: (see other slides)
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3. Table of Contents Overview QFD: Step by Step Exercise
Comparison of Different RE Techniques
Application of QFD on Software Engineering
QFD software list
Discussion
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4. Overview of QFD The History of QFD. What is QFD? Why use QFD?
Characteristics of QFD?
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5. History of QFD 1960’s, Yoji Akao conceptualized QFD.
Statistical Quality Control, SQC, was the central quality control activity after WWII.
SQC became Total Quality Control, TQC.
QFD was derived from TQC.
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6. First Application of QFD
1966, Bridgestone Tire Corp first used a process assurance table.
1972, the process assurance table was retooled by Akao to include QFD process.
1972, Kobe Shipyards (of Mitsubishi Heavy Industry) began a QFD Oil Tanker project.
1978, Kobe Shipyards published their quality chart for the tanker.
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7. QFD Takes Hold The first paper on QFD was published in 1972.
In 1978, the first book on QFD was published in Japanese.
In 1983, the first English QFD article was published in North America.
By the late 1970’s most of the Japanese manufacturing industry were using QFD.
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8. QFD in North America
QFD spread rapidly in North America during the 1980’s
The Automobile industry and Manufacturing began heavy use of QFD at this time.
QFD symposiums (North American, Japanese, European, International) were set up to explore research relating to QFD techniques.
The QFD institute was formed in 1994.
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9. QFD in Software Engineering
The QFD Research Group was seeking research relating to QFD in Software Engineering since 1987.
A new style of QFD, Software QFD (SQFD), has emerged.
DEC, AT&T, HP, IBM and Texas Instruments have all published information relating to SQFD (Haag, 1996).
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10. Additional Techniques
There are many techniques which are a style of QFD or are used to enhance QFD.
These include: TRIZ, conjoint analysis, the seven product planning tools, Taguchi methods, Kano model, SQFD, DQFD, Gemba, Kaizen, Comprehensive QFD, QFD (N), QFD (B).
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11. Overview of QFD The History of QFD. What is QFD? Why use QFD?
Characteristics of QFD?
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12. What is QFD?
Quality Function Deployment, QFD, is a quality technique which evaluates the ideas of key stakeholders to produce a product which better addresses the customers needs.
Customer requirements are gathered into a visual document which is evaluated and remodeled during construction so the important requirements stand out as the end result.
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13. The QFD Paradigm
QFD provides the opportunity to make sure you have a good product before you try to design and implement it.
It is about planning and problem prevention, not problem solving (Eureka, 1988).
QFD provides a systematic approach to identify which requirements are a priority for whom, when to implement them, and why.
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14. High-Level QFD
Requirements are initially elicited using other RE techniques (interviewing, brain-storming, focus-groups, etc).
QFD involves the refinement of requirements using matrices and charts based on group decided priorities.
There are 4 Phases of QFD. Each Phase requires internal iteration before proceeding to the next. Once at a Phase you do not go back.
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15. What Does QFD Require? QFD requires time, effort, and patience.
QFD requires access to stakeholder groups.
The benefits of QFD are not realized immediately. Usually not until later in the project or the next project.
QFD requires full management support. Priorities for the QFD process cannot change if benefits are to be realized.
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16. Overview of QFD The History of QFD. What is QFD? Why use QFD?
Characteristics of QFD?
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17. Why use QFD?
The QFD process leads participants to a common understanding of project direction and goals.
QFD forces organizations to interact across their functional boundaries (Hales, 1995).
QFD reduces design changes (Mazur, 2000).
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19. QFD Artifacts Prioritized list of customers and competitors.
Prioritized list of customer requirements.
Prioritized list of how to satisfy the requirements.
A list of design tradeoffs and an indication of how to compromise and weigh them.
A realistic set of target values to ensure satisfaction.
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20. What about Cost?
Cost reduction is not mentioned as a ‘Why to use QFD’.
Initial costs will be as high or a little higher compared with traditional techniques.
You are seeking long term savings in that product or the products that follow.
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21. Overview of QFD The History of QFD. What is QFD? Why use QFD?
Characteristics of QFD?
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22. Characteristics of QFD
4 Main Phases to QFD
Product Planning including the ‘House of Quality’ (Requirements Engineering Life Cycle)
Product Design (Design Life Cycle)
Process Planning (Implementation Life Cycle)
Process Control (Testing Life Cycle)
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23. QFD Phase 1 Phase 1 is where most of the information is gathered.
Getting good data is critical. Any mistakes in requirements here will be magnified later.
Software Engineers should spend most of our time in this Phase.
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24. The House of Quality (HoQ)
Is a set of matrices which contains the requirements (What’s) and the detailed information to achieve those requirements (How’s, How Much’s).
Stakeholder groups fill in the matrices based on their priorities and goals.
A key to the HoQ is making sure each group answers the same question about the same relationship, What vs How, cell.
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25. Key Items to Address in HoQ
QFD Team Mission Statement.
Who is the customer?
What are the Requirements?
How important is each requirement?
How will you achieve each requirement?
Complete the Relationship Matrix (what’s vs how’s).
Which how’s are the most important?
What are the tradeoffs between the how’s?
What target values should be established?
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26. QFD: Step by Step Guide How QFD Works
Step by Step Guide to Build a “House of Quality”
Example:
Web page development
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27. How QFD Works
Customer-requirements-driven design and production planning process
Rationale is that product quality is measured by customer satisfaction and customers are satisfied if their needs or requirements are met
QFD is building requirements into products.
Inputs customer requirements
Outputs production procedures for producing a product to satisfy customers.
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28. How QFD Works (2) Conceive Design Process Production
Technical
Specifications
Design
Process
Methods
Tools
Production
High Level Design
Procedures
Requirements
QFD Planning Process
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29. House of Quality Example Correlation Matrix (Hows vs. Hows)
Technical Specifications
(Hows)
Whys
Customer Requirements
(Whats)
Relationship Matrix
(Whats vs. Hows”)
Customer Importance Rating
Customer Market Evaluation
(Whats vs. Whys)
How muchs
Technical Competitive Evaluations
Target Goals
Example
Degree of Technical Difficulty
Overall Importance Ratings
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30. Customer Requirements
"Voice of Customer” (VOC)
Are “whats”
Expressed in customer’s own language
Qualitative, vague, ambiguous, incomplete, inconsistent
Group session
Categorization and organization
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31. Technical Specifications
Voice of the Engineers or Designers (“hows”).
Interpretations of "whats" in terms of technical specifications or design requirements (designers’ language)
Potential choices for product features
Each "whats" item must be converted (refined) to “how(s)”
They have to be actionable (quantifiable or measurable)
Free of technology and implementation creates flexibility for design
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32. Relationship Matrix “Whats” vs. “Hows”
Correlates how “hows” satisfy “whats”
Use symbolic notation for depicting weak, medium, and strong relationships
A weight of or is often used
More “strongs” are ideal
Cross-checking ability
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33. Customer Prioritization
Prioritizing the importance of each “whats” item to the customer.
Rate each “whats” item in 1 to 5 rating
Completed by the customer
AHP can be used
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34. Customer Market Competitive Evaluations
Comparison of the developer's product with the competitor’s products
Question: “Why the product is needed?”
The customer evaluates all products comparing each “whats” item
Rating of 1 of 5 is given
The results help position the product on the market.
Identify the gaps
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35. Target Goals “How much’s" of the “Hows“ (measurement)
Answers a common design question: "How much is good enough (to satisfy the customer)?“
Not known at the time when the "hows" are determined.
They are determined through analysis.
Clearly stated in a measurable way as to how customer requirements are met
Provides designers with specific technical guidance
Can be used for (acceptance) testing.
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36. Correlation Matrix “Roof” part
Identifies how “hows” items support (positive) or conflict (negative) with one another
May combine strong positive items to reduce development effort
Find trade-offs for negative items by adjusting “how much” values.
Trade-offs must be resolved or customer requirements won’t be fully satisfied.
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37. Technical Specifications Competitive Evaluation
Similar to customer market competitive evaluations but conducted by the technical team
Technical advantages or disadvantages over competitor products
Conflicts may be found between customer evaluations and technical team evaluations
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38. Technical Difficulty Assessment
Performed by technical teams
Helps to establish the feasibility and realization of each "hows" item
1 to 5 ratings
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39. Overall Importance Ratings
Only time when math is required
Calculated overall ratings
Function of relationship ratings and customer prioritization ratings.
Used to determine a set of technical specifications / requirements needed for the next phase.
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40. Decisions for Phase 2 The “Hows” are analyzed
Overall importance ratings
Technical difficulties
Competitive ratings
Decisions on design requirements are made
Start product design phase
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41. SQFD QFD for software Software Engineering is requirements driven
Addresses quality issues in software development
Usually use QFD phase 1
Focuses on requirements
“Hows” vs. functional or non-functional requirements
“How much’s” vs. Testing
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42. How to Apply QFD to SE Use for new or upgrade type of projects
Requirements refinements
Customer has ideal, developer has solution
Ideal to know application domain knowledge
Software for internal use
Software for general use such as OS, word processor etc.
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43. Presentation Summary Disadvantages of SQFD Advantages of SQFD
How to Make SQFD work
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44. Disadvantage of SQFD - What Makes QFD Unsuitable for SE
Time and resources consuming
Process limitation in iteration support
Does not support common language between users and developers
Documentation requirements
Focus on quality other than functionality
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45. Benefits of SQFD Communications among groups Decision justification
Metrics
Cross-checking
Avoid loss of information
Shortens the SDLC
Source:
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46. Advantages of SQFD Customer / User involvement Focus on customer needs
Team builder
Improve product or service quality
Shorter development cycles
Lower costs and greater productivity
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47. Advantages of SQFD (2) Reduces design changes
Good for communication, decision making and planning
Allows for a lot of information in a small space
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48. How to Make SQFD Work Obtain management commitment
Establish clear, up-front objectives
Strong technical know-how
Establish multi-functional team.
Designate a facilitator
QFD training
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49. How to Make SQFD Work (2)
Get an adequate time commitment from team members
Schedule regular meetings
Avoid first using QFD on a large, complex project
Avoid gathering perfect data
Avoid technical arrogance
Focus on the important items
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50. Conclusion
QFD originated in the Manufacturing industry and has been applied to software engineering
QFD addresses the quality of the product
SQFD is QFD for software
QFD, JAD, SSM, PD, RAD and OO all have their merits and faults
The use of the technique depends on the project
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51. QFD vs. JAD
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52. QFD vs. JAD cont.
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53. QFD vs. JAD cont.
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