Quality%20Function%20Deployment

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Quality Function Deployment
Acknowledging

• David Menks
• Anwar Ahmed
• Kaijun Fu

Found at http//sern.ucalgary.ca/kjfu/courses/SE
NG613/teamwork.html
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Other Sources on QFD/SQFD

• Good overview can be found athttp//pages.cpsc.u
  calgary.ca/johnsonk/SENG/SENG613/Project/report.h
  tm
• Downloadable tool www.iti-oh.com
• SQFD paper (see other slides)

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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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Overview of QFD

• The History of QFD.
• What is QFD?
• Why use QFD?
• Characteristics of QFD?

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History of QFD

• 1960s, 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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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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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 1970s most of the Japanese
  manufacturing industry were using QFD.

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QFD in North America

• QFD spread rapidly in North America during the
  1980s
• 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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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, ATT, HP, IBM and Texas Instruments have all
  published information relating to SQFD (Haag,
  1996).

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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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Overview of QFD

• The History of QFD.
• What is QFD?
• Why use QFD?
• Characteristics of QFD?

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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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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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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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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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Overview of QFD

• The History of QFD.
• What is QFD?
• Why use QFD?
• Characteristics of QFD?

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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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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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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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Overview of QFD

• The History of QFD.
• What is QFD?
• Why use QFD?
• Characteristics of QFD?

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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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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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The House of Quality (HoQ)

• Is a set of matrices which contains the
  requirements (Whats) and the detailed
  information to achieve those requirements (Hows,
  How Muchs).
• 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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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 (whats vs
  hows).
• Which hows are the most important?
• What are the tradeoffs between the hows?
• What target values should be established?

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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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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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How QFD Works (2)
Conceive
Design
Process
Production
Technical Specifications
Methods Tools
High Level Design
Procedures
Requirements
QFD Planning Process
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House of Quality
Correlation Matrix (Hows vs. Hows)
Technical Specifications (Hows)
Whys
Customer Requirements (Whats)
Relationship
Matrix (Whats vs. Hows)
Customer Market Evaluation (Whats vs.
Whys)
Customer Importance
Rating
How muchs
Technical Competitive Evaluations
Target Goals
Example
Degree of Technical Difficulty
Overall Importance Ratings
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Customer Requirements

• "Voice of Customer (VOC)
• Are whats
• Expressed in customers own language
• Qualitative, vague, ambiguous, incomplete,
  inconsistent
• Group session
• Categorization and organization

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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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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

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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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Customer Market Competitive Evaluations

• Comparison of the developer's product with the
  competitors 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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Target Goals

• How muchs" 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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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 wont be fully satisfied.

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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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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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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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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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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 muchs vs. Testing

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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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Presentation Summary

• Disadvantages of SQFD
• Advantages of SQFD
• How to Make SQFD work

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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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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

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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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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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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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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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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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QFD vs. JAD
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QFD vs. JAD cont.
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QFD vs. JAD cont.