Lecture 6-Quality Function Deployment

7/29/2019 Lecture 6-Quality Function Deployment

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QUALITY FUNCTION

DEPLOYMENT



History of QFD

QFD originated at Bridgestone Tyre, Kurume

Plant

First application at Mitsubishi, Heavy Industries

Ltd., in the Kobe Shipyard, Japan in 1972



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Toyota employed QFD technique to overcomethe rusting problem of cars

QFD helped Toyota with the door problems intheir pick up trucks.

Also implemented by Toyota in the productionof mini-vans in 1977

– 20% reduction in startup costs in 1979

– 38% reduction by November 1982

– 61% (cumulative) reduction by April 1984

Introduced in US in 1984 by Xerox



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A system for translating specific customer

needs into detailed product requirements

which are deployed throughout design,

production, marketing and support

operations.

QUALITY FUNCTION DEPLOYMENT



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QFD – Purpose

Translate consumer’s voice into technical design

requirements

Determine & prioritize customer needs Translate customer needs to product design

parameters

Coordinate efforts and skills of an organization froma project’s inception to its completion

Ensure customer expectations

Avoid manufacturing catastrophe



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QFD can be used to: Reduce product development time

Cut start-up & engineering costs

Reduce time to market

Reduce the number of design changes

Lower rework

Reduce facility’s maintenance/operation costs

Improve quality



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Improves

Customer Satisfaction

Reduces

Implementation time

Promotes Teamwork

Provides Documentation

• Creates focus on customer requirements

• Uses competitive information effectively

• Prioritizes resources

• Identifies item that can be acted upon

• Decreases midstream design changes

• Limits post introduction problems

• Avoids future development redundancies

• Identifies future application opportunities

• Based on consensus

• Creates communication at interfaces

• Identifies actions at interfaces

• Creates global view out of details

• Documents rationale for design

• Is easy to assimilate

• Adds structure to information

• Provides framework for sensitivity analys



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The Overall GoalIncrease customer satisfaction

=Increase business success



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House of Quality QFD’s primary tool

Arranges facts Forms relationships

Measures success



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The What's & How's What side

– Customer requirements/needs

How side

– How to meet those needs



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House of Quality

Technical requirements

Voice of

the

customer

Relationship

matrix

Technical requirement

priorities

Customer

requirement

priorities

Competitive

evaluation

Interrelationships



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A

D

B

C E F

G

Conduct marketing researchto determine the VOCsPlace it in part A.

Determine the varioustechnical requirementswith respect to VOCs.

Place them in Part B.

Determine the relationshipvalues between various VOCsand technical requirements.

Place these in part C.

Determine the correlationvalues between varioustechnical requirements.Place them in Part D.

S th t t d t i



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Survey the customers to determinethe importance of ratings of variousVOCs.Place these in Part E.

Survey the customers to determinethe ratings of the company and itsmain competitors wrt the variousVOCs.

Place these in Part F.Determine the ratings of thecompany and its main competitorswrt the various technical requirements

Place these in part G.

Find the absolute and relativeweights of the various technicalrequirements and select the technicalrequirements with high weights.

A F

B

C

G

D

E



EXAMPLE

A Company manufactures bicycle

components. To expand their product line

they want to produce Handlebar stems for mountain bikes. For which they use QFD.

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STEP 1. LIST CUSTOMER REQUIREMENTS (WHATS)



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STEP 2. LIST TECHNICAL DESCRIPTORS (HOWS)



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STEP 3. Develop a Relationship Matrix betweenWhats and Hows (contd.)

Relationship Matrix

• A solid circle represents a strong relationship

• A single circle represents a medium relationship.

• A triangle represents a weak relationship.

• The box is left blank if no relationship exists.

Later, the symbols are replaced with numbers.

= 9

= 3

= 1



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Step 4. Develop an InterrelationshipMatrix between HOWs

The roof of the house, called thecorrelation matrix

Identifies interrelationships betweeneach of the technical descriptors

= strong positive

= positive

X = negative

* = strong negative



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Step 5. Competitive Assessments

Customer and Technical Competitiveassessment

The numbers 1 through 5 are listed inthe respective column and row.

(1 being the worst and 5 the best)



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Step 6. Develop prioritized

customer requirements Importance to customer

Target Value

Scale-up factor

Absolute Weight = imp to customer X scale

up factor



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Step 7. Develop prioritizedtechnical descriptors

Degree of difficulty

Target Value

Absolute weight: the dot product of thecolumn in the relationship matrix and the

column for importance to customer

Relative Weight: the dot product of thecolumn in the relationship matrix and the

column for absolute weight in the prioritized

customer requirements



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Higher absolute and relative ratings

identify areas where engineering

efforts need to be concentrated.

The primary difference between these

weights is that the relative weight alsoincludes information on customer

scale-up factor.



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Problems With QFD

Matrix is too large

Customer priorities not clear

Customers’ stated preferences and actions differ

QFD is messy

Th A t f Q lit K ’ M d l



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Three Aspects of Quality: Kano’s Model Dissatisfiers are productcharacteristics that are “basic” or “expected” andare usually taken forgranted by customerswhen present.

Delighters are product characteristics that are “attractive” or “exciting” which often pleasantly surprise customers

when they are first encountered.

Delighters

SatisfiersDissatisfiers

Performance

100%0%

Customer Satisfaction

-

+

Satisfiers are product

characteristics thatcustomers want in theirproducts and are “one dimensional” or “linear” inthe sense of the more weprovide, the happier thecustomer.



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Kano’s Model (contd.)

Dissatisfiers:

– Cause dissatisfaction only when missing; customercomplaints are the primary source of information forfinding them

Satisfiers:

– Tend to be easy to measure and are usually used forbenchmarking and comparative analysis

Delighters:

– Difficult to assess since they represent “unexpected quality” which cannot be ascertained throughsurveys and/or complaints

– Represent “unspoken” and “unmet” needs, possiblynew markets