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Quality Function

Deployment

David MenksAnwar Ahmed

Kaijun Fu

Found at: http://sern.ucalgary.ca/~kjfu/courses/SENG613/teamwork.htmlFound at: http://sern.ucalgary.ca/~kjfu/courses/SENG613/teamwork.html

Acknowledging:

Nov 23, 2000 SENG 613 QFD 2

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)

Other Sources on QFD/SQFD

Nov 23, 2000 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

Nov 23, 2000 SENG 613 QFD 4

Overview of QFD The History of QFD.

What is QFD? Why use QFD? Characteristics of QFD?

Nov 23, 2000 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.

Nov 23, 2000 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.

Nov 23, 2000 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.

Nov 23, 2000 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.

Nov 23, 2000 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).

Nov 23, 2000 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).

Nov 23, 2000 SENG 613 QFD 11

Overview of QFD The History of QFD.

What is QFD?

Why use QFD? Characteristics of QFD?

Nov 23, 2000 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.

Nov 23, 2000 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.

Nov 23, 2000 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.

Nov 23, 2000 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.

Nov 23, 2000 SENG 613 QFD 16

Overview of QFD The History of QFD. What is QFD?

Why use QFD?

Characteristics of QFD?

Nov 23, 2000 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).

Nov 23, 2000 SENG 613 QFD 18

Nov 23, 2000 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.

Nov 23, 2000 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.

Nov 23, 2000 SENG 613 QFD 21

Overview of QFD The History of QFD. What is QFD? Why use QFD?

Characteristics of QFD?

Nov 23, 2000 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)

Nov 23, 2000 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.

Nov 23, 2000 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.

Nov 23, 2000 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?

Nov 23, 2000 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

Nov 23, 2000 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.

Nov 23, 2000 SENG 613 QFD 28

How QFD Works (2)

Conceive

Design Process Production

Requirements

Technical

Specifications

High Level Desig

n

Methods

Tools

QFD Planning Process

Procedures

Nov 23, 2000 SENG 613 QFD 29

House of Quality

Customer Requirements

(Whats)

Relationship Matrix

(Whats vs. Hows”)

Customer Market Evaluation

(Whats vs. Whys)

Degree of Technical Difficulty

Technical Specifications

(Hows)

Correlation Matrix(Hows vs. Hows)

How muchs

Whys

Target GoalsTechnical Competitive

Evaluations

Overall Importance Ratings

Customer

Importance

Rating

Example

Nov 23, 2000 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

Nov 23, 2000 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

Nov 23, 2000 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

Nov 23, 2000 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

Nov 23, 2000 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

Nov 23, 2000 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.

Nov 23, 2000 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.

Nov 23, 2000 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

Nov 23, 2000 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

Nov 23, 2000 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.

Nov 23, 2000 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

Nov 23, 2000 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

Nov 23, 2000 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.

Nov 23, 2000 SENG 613 QFD 43

Presentation Summary Disadvantages of SQFD Advantages of SQFD How to Make SQFD work

Nov 23, 2000 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

Nov 23, 2000 SENG 613 QFD 45

Benefits of SQFD

Communications among groups Decision justification Metrics Cross-checking Avoid loss of information Shortens the SDLCSource: http://www.acm.org/pubs/articles/journals/cacm/1996-39-1/p41-haag/p41-haag.pdf

Nov 23, 2000 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

Nov 23, 2000 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

Nov 23, 2000 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

Nov 23, 2000 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

Nov 23, 2000 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

Nov 23, 2000 SENG 613 QFD 51

QFD vs. JAD QFD JAD Type Group session

approach Group session approach

Goal Clients quality need

Improve the system

Driving force Customer voice Human communication

Defect Prevention

Suitable Suitable

Nov 23, 2000 SENG 613 QFD 52

QFD vs. JAD cont.

QFD JAD

Communication/ Cooperation

Software personnel & their users

Users & developers

>10000 users [Capers Jones, 1995]

No such limitations

Not suitable

Nov 23, 2000 SENG 613 QFD 53

QFD vs. JAD cont.

QFD JAD

Focus House of quality Proper communication

Fail Lack of support of Top management

Automated tools are not well & facilitator bypassed