Q uality F unction D eployment

1. Quality Function Deployment Acknowledging: David Menks Anwar Ahmed Kaijun Fu Found at: http://sern.ucalgary.ca/~kjfu/courses/SENG613/teamwork.html

2. Other Sources on QFD/SQFD • Good overview can be found at:http://pages.cpsc.ucalgary.ca/~johnsonk/SENG/SENG613/Project/report.htm • Downloadable tool:www.iti-oh.com • SQFD paper: (see other slides) SENG 613 QFD

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 SENG 613 QFD

4. Overview of QFD • The History of QFD. • What is QFD? • Why use QFD? • Characteristics of QFD? SENG 613 QFD

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. SENG 613 QFD

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. SENG 613 QFD

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. SENG 613 QFD

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. SENG 613 QFD

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). SENG 613 QFD

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). SENG 613 QFD

11. Overview of QFD • The History of QFD. • What is QFD? • Why use QFD? • Characteristics of QFD? SENG 613 QFD

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. SENG 613 QFD

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. SENG 613 QFD

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. SENG 613 QFD

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. SENG 613 QFD

16. Overview of QFD • The History of QFD. • What is QFD? • Why use QFD? • Characteristics of QFD? SENG 613 QFD

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). SENG 613 QFD

18. SENG 613 QFD

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. SENG 613 QFD

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. SENG 613 QFD

21. Overview of QFD • The History of QFD. • What is QFD? • Why use QFD? • Characteristics of QFD? SENG 613 QFD

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) SENG 613 QFD

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. SENG 613 QFD

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. SENG 613 QFD

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? SENG 613 QFD

26. QFD: Step by Step Guide • How QFD Works • Step by Step Guide to Build a “House of Quality” • Example: • Web page development SENG 613 QFD

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. SENG 613 QFD

28. How QFD Works (2) Conceive Technical Specifications Design Process Methods Tools Production High Level Design Procedures Requirements QFD Planning Process SENG 613 QFD

29. House of Quality 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 SENG 613 QFD

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 SENG 613 QFD

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 SENG 613 QFD

32. Relationship Matrix • “Whats” vs. “Hows” • Correlates how “hows” satisfy “whats” • Use symbolic notation for depicting weak, medium, and strong relationships • A weight of 1-3-9 or 1-3-5 is often used • More “strongs” are ideal • Cross-checking ability SENG 613 QFD

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 SENG 613 QFD

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 SENG 613 QFD

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. SENG 613 QFD

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. SENG 613 QFD

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 SENG 613 QFD

38. Technical Difficulty Assessment • Performed by technical teams • Helps to establish the feasibility and realization of each "hows" item • 1 to 5 ratings SENG 613 QFD

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. SENG 613 QFD

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 SENG 613 QFD

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 SENG 613 QFD

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. SENG 613 QFD

43. Presentation Summary • Disadvantages of SQFD • Advantages of SQFD • How to Make SQFD work SENG 613 QFD

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 SENG 613 QFD

45. Benefits of SQFD • Communications among groups • Decision justification • Metrics • Cross-checking • Avoid loss of information • Shortens the SDLC Source: http://www.acm.org/pubs/articles/journals/cacm/1996-39-1/p41-haag/p41-haag.pdf SENG 613 QFD

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 SENG 613 QFD

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 SENG 613 QFD

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 SENG 613 QFD

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 SENG 613 QFD

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 SENG 613 QFD