Exercise Quality Management - wzl.rwth-aachen.de · Time until pizza is delivered: Question: Less than 30 min.? Answer: That's normal. Question: More than 30 min.? ... Quality Function

Quality Management – Prof. Schmitt Exercise 07

Quality Function Deployment E 07 page 0

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© WZL/Fraunhofer IPT

Exercise Quality Management

07 Quality Management in the Early Phases –

Focus Product

Dipl.-Ing. Dipl. Wirt.-Ing. Björn Falk

Dipl.-Ing. Dipl. Wirt.-Ing. Björn Falk

Group Perceived Quality & Product Value Management

Department Quality Management

Chair of Metrology and Quality Management

Steinbachstr. 25 (ADITEC), D-52074 Aachen,

Tel.: +49 (0)241 80-27667

Fax: +49 (0)241 80-22193

Email: [email protected]

URL: http://www.wzl.rwth-aachen.de



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Seite 1© WZL/Fraunhofer IPT

Customer Statements - Examples

� quiet solid

� fragile cover

� reliable affecting device

� cut off connections or the refusal of the commands are only two follows of its pettish attitude

� I once switched it on in the cinema and I nearly went blind

� disoriented software

� good gadget, good freaky functions

� dull sound

� distorted sound

� spongy keyboard

� weak keyboard

� it does not sound strange when you squeeze it, not like it couldbe damaged easily

� after the first downthrow the display went crazy and you could not use it any longer



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Identification of Critical Customer Requirements

Customers Need

Specific Measurable CriteriumCustomers ExpectationsReal Customer Statements

�All required packages/ patches

contained in the installation file.

�Software is 100% compatible to

customers IT-System.

�The software doesn‘t work the way

the salesman has promised.

�These Software doesn‘t work

properly.

�No further choices to be made on a (telephone) menu.

�Customer is connected to the

responsible serviceman within 30

sec.

�Wants to speak to a serviceman.� I‘ll talk to the serviceman right now.

I won‘t accept waiting any longer.

�Chainsaw starts with second pull of

the starter rope.

�Chainsaw starts with a power of

XY N pulling on the rope.

�Want to start the chainsaw fast.�The chainsaw shall be easy to start.

�The rope shall be pullable with less

power.

Voice of Customer (VOC)Critical Customer Requirement

(CCR)

Identification of critical Customer Requirements

The translation of the customers voice into measurable specific product characteristics is essential for product development.

For customer oriented development the critical characteristics have to be identified and target values to be defined.



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Kano-Model

Fulfilment of requirements

Quality and performance

requirementes

e.g.

low fuel consumption

e.g. dynamic Navigation system

Requirements for

exciting characteristics

Basic requirements

e.g. Airbags

Cu

sto

me

rs

ati

sfa

cti

on

Tim

e

Indifferent quality characteristics

Reverse quality

characteristics



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Determination of Product Characteristics which delight

� Characteristics:

– The product characteristics are valuable for the customer

– They are unknown to the customer.

� Determination:

– Careful choice of target groups (Interviews with single

persons or small groups)

– The specific topics are mostly unknown

– Essential are:

� Open minded users who can imagine to use alternative

services, products or a combination of both. (extern)

� creative engineers with a strong comprehension of

feasible concepts. (intern)



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Application of the Kano-Model: Determination of Critical CustomerRequirements (CCR)

� Field of application:

– Determination which products or services are (not) esteemed

by the customer.

– Validation of critical customer requirements.

� Approach:

– Specific questioning of the customer regarding special

characteristics or requirements

� Assessment of the fulfillment of a requirement

� Assessment of the non-fulfillment of a requirement

– Structuring the statements into:

� Delightment („I‘m loving it“)

� Expectation („That goes without saying!“)

� Indifference („I‘m not sure“)

� Dislike („I don‘t like it“)

Tim

e



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dislike

indiffer

ence

Expect.

delight

fulfilm

en

t

dislikeindiffer

ence

expecta

tion

delight

Non-fulfilment

Application of the Kano-Model

� Characteristic which delight the customer

� Quality- and Performance characteristic/ requirement

� Basic characteristic/ must-be requirement

� Quality Characteristic with potential for improving through substitution by other characteristics.

� „Bad idea“ or reason for dissatisfaction with the product.

� Customer statement is inappropriate.



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dislike

indifference

expect

delight

Fu

lfilme

nt

dislike

indifference

expect

delightg

Non-fulfilment

Application of the Kano Model – An Example

� Time until pizza is delivered:

� Question: Less than 30 min.?

� Answer: That's normal.

� Question: More than 30 min.?

� Answer: That's not acceptable.

– A waiting time of more than 30 min. will not be accepted.

� Question: Less than 15 minutes?

� Answer: I‘ll be delighted.

� Question: More than 15 min.?

� Answer: That's normal.

– A waiting time of less than 15 min is a characteristic which delights the customer.

� To be evaluated:

– How is the influence on costs if characteristic is realized.

– Is the market attractiveness high enough under consideration of monetary matters?dislike

indifference

expect

delight

Erfü

llun

g

dislikeindifference

expectdelightg

Nichterfüllung

1

2

1

2



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Determination ofCustomer Requirements

1

Correlationsbetween different

Quality Characteristics

3

Assessing the correlationbetween Customer Requirements

and Quality Characteristics

4

House of Quality - Procedure

What?

Selection of importantQuality Characteristics

2

How?

Ranking theQuality Characteristics

5

How much?

Derivate new target valuesand other figures

6

Why?

House of Quality – Procedure:

1. Determination of Customer Requirements (What?)

2. Selection of important Quality Characteristics (How?)

3. Correlations of the different Quality Characteristics

4. Assessing the correlation between Production Requirements and Quality Characteristics

5. Ranking the Quality Characteristics (How much?)

6. Derivate new target values and other figures (Why?)



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Four phases after ASI - American Supplier Institute

closing force [Fs]

extruder speed [n]

controller

pressing pressure [pd]

Easy-to-close doors

10N

Product planning

. . .

Extrusion pressure

30

Process planning

. . .

Extruder speed [n]

250

Production planning

. . .

Closing force [Fs]

7

Sealing

N

mm²

Component planning

. . .

1

min

Clo

sin

g forc

e [

Fs]

Pre

ssin

g p

ressure

[pd]

Extr

uder

speed [n]

Contr

olle

r



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1 6. .

CR: Customer Requirements

QC: Quality Characteristics

Customer Requirements

Directionof improvement

Quality

Characteristics

2

Correlation

between

CR and QC

4

5

Cu

sto

me

re

va

lua

tio

n

Be

nch

ma

rkin

g(C

usto

me

r

vie

w)

Benchmarking(Technical

view)

6

6

6Steps for developing a

House of Quality

House of Quality - Structure

Imp

ort

an

ce

Cu

sto

me

rR

eq

uir

em

en

ts1

Important quality

characteristics

Correlation

3

Techn. difficulty

Techn. evaluation

QFD - Quality Function Deployment

House of Quality – Structure:

Today the House of Quality is one of the most commonly used tools for implementing Quality Function Deployment, providing a combination of various matrices, lists and tables, to support the individual transformation steps in QFD process. The conversion of Customer Requirements into Quality Characteristics is supported and evaluated by using weighted relations to link the contents of the various matrices and tables.



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� The tyre should be rain capable� The tyre should have good emergency running properties

� The tyre shouldn‘t cause too much noise� The tyre should provide low fuel consumption

� The tyre should have a high durability

� The tyre should have a sportive handling

Determination of Customer Requirements

Customer Requirements:

Application of the QFD Method

Determination of Customer Requirements:

The QFD Method will be used for designing a car tyre. At first a primary investigation in form of a survey is accomplished.

The exemplary results of a survey are shown above.



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Pair wise Comparison

...

...

...

requirement B

requirement A


0

req

uir

em

en

tA

2

req

uir

em

en

tB

we

igh

tG

i

su

mS

i

...

„A“ more important than „B“

inscribe „2“

Matrix field for inscription

of the lines summation.

„B“ less important than „A“

inscribe „0“

Pair-wise comparison

At first the QFD weightings are determined with a pair wise comparison of all requirements which have resulted from the survey. In the following all Customer Requirements in the matrix are compared with each other.

If a Customer Requirement (e.g. “A” from line 1) is more important than the other requirement in the pair (“B” from column 2), a “2” has to be inscribed in the appropriate matrix array. In case of the same importance a “1”, in case of less importance a “0” has to be inscribed.

To get the weighted Customer Requirements use the following formulas:

for a range of 1 to 5


Wi : weight; Si : sum of correlating line; Smax : maximum line sum;

Smin : minimum line sum

Last but not least the weighted Customer Requirements are inscribed into the House of Quality.

+

−

−⋅= 14

minmax

min

SS

SSRdW i

i

+

−

−⋅= 19

minmax

min

SS

SSRdW i

i



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Exercise: Pair wise Comparison

A customer survey provides the following information to you:

� The tyres‘ rain capability is more important than low noise emission or low fuel

consumption as well as the other requirements.

� The good emergency running capabilities are as same important as high speed capability

and a sportive handling but are less important than a high durability.

� Just the rain capability is more important than a low fuel consumption.

� Low noise emission is more important than good emergency running capabilities, a

sportive handling and high speed capability but less important than the other

requirements.

� High durability is as same important as sportive handling and more important than the

high speed capability.

� Sportive handling and high speed capability are of the same importance.

Calculate the weight of each customer requirement by the use of the pair wise comparison.



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Excercise: Comparison in Pairs

high-speed capable

low fuel consuption

low noise

good emergency running properties

rain capable

customer requirements rain

ca

pa

ble

go

od

em

erg

en

cy

run

nin

gp

rop

ert

ies

low

no

ise

low

fuelco

nsu

ptio

n

hig

h-s

pe

ed

ca

pa

ble

hig

h d

ura

bili

ty

we

igh

tW

i

su

mS

i

high durability

sportive handling

sp

ort

ive

ha

nd

ling

0

0

0

2

0

0

0

0

1

2

2

2

0

2

0

2

2

2

1

2

2

10

6

2

12

1

4

3

1

5

0

2

0

0

2

00 2 2 2 7 3

00 1 0 1 3 11

1

2

2

1

2

1

Smax= 12

Smin= 2

Smax - Smin= 10

Rd(4x(4/10)+1)



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House of Quality – car tyre

Strong Correlation

Medium Correlation

Weak Correlation

= 9

= 3

= 1

Ccusto

mer

Evalu

ation


Importance tr

ead

patt

ern

nylo

noverl

ays

ste

elb

elt

fabric

layer

inn

er

layer

sid

efr

am

e

core

pro

file

core

chip

per

rain capable 5

1 2 3 4 5 6

good emergency runningproperties

1

low noise 3

low fuel consumption 4

high-speed capable 1

high durability 3

sportive handling 1

1234

56

118 9 57 18 30 46 12 37 12

10 1 5 2 3 4 1 3 1

Target Values

Absolute Importance

Importance 1-10

Technical Evaluation

Com

pon

ents

Strong Positive

Positive

Negative

Strong Negative

+++-

Directionof Improvement

Maximum

Neutral

Minimum

Product B

Product A

Benchmarking

- Customer Evaluation- Technical Evaluation

--

Case study “car tyre”: Completely elaborated House of Quality

The picture shows the QFD on the production level by the example of a car tyre. The proceeding differs from the ASI concept and shows that the QFD works as a flexible instrument.

In the first House of Quality (HoQ) of this example it is not possible to name target values because the components can’t be defined in physical values. Therefore it is not possible to identify the direction of improvement and to sign in the matrix of the rooftop.

This HoQ analyses the influence of Customer Requirements on the product components.

Example – Planning of Components

The HoQ of the car tyre shows that the technical parameter “tread pattern” is related to most of the Customer Requirements. Now this parameter will be shown in detail.

The detailed view could also have been achieved in the very first HoQ, but then it wouldn’t have been that clearly arranged. It has to be decided individually which procedure is suited best regarding time, profit and usage.

The HoQ concerning the tread pattern offers the possibility to plot the target values, the direction of improvement and the matrix of the rooftop.



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Quality Characteristics of the component “tread pattern”

� cap-material: % silica

� cap-material: % flexibiliser

� cap-profile: share of negative tread (profile)

� cap-profil: profile depth

� base: density

� base: hardness

� shoulder: angle

� shoulder: hardness

� ...

Quality Characteristics:

Identification of Quality Characteristics (QC)

In the following work step the Quality Characteristics of the tread pattern will be identified. They represent measurable criteria for the fulfilment of the Customer Requirements and can be used for the technical implementation.



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Rooftop Matrix

custo

mer

evalu

atio

n

cap base shoulder

material profil

customer requirements

importance

% s

ilica

% f

lexi

bili

ser

quota

of

tread

deepe

nin

gs

tread d

epth

de

nsety

hard

ness

angle

hard

ness

custo

mer

evalu

atio

n

rain capable 5

1 2 3 4 5 6

good emergency running

prosperties1

low noise 3



high durability 3

sportive handling 1

15% 10% 7% 6mm0,8

kg/dm3

90o

Shore A10o 85

o

Shore A

12

3456

69 75 94 78 51 43 6 10

7 8 10 8 6 5 1 1

technical evaluations

target values

absolute importance

importance 1-10

- - + +

qualit

y -

chara

cte

ristics

shouldermaterial profile

cap base

% s

ilica

% f

lexib

ilise

r

Qu

ota

of

tre

ad

de

ep

en

ing

s

tre

ad

de

pth

de

nsity

ha

rdn

ess

an

gle

ha

rdn

ess

- - + +

Rooftop Matrix

The Rooftop Matrix is used for the identification of interactions between the various Quality Characteristics.

These can be of different characteristic:

- Strong Positiv interaction ++

- Positiv interaction +

- Neutral no inscription

- Negative interaction -

- Strong negative interaction --

Example:

Silica and flexibiliser are both parts of the cap material. The procentual quota of the flexibiliser should stay the same but the quota of silica should be raised. Because the material is a mixture of both a procentualchange of one part influences the quota of the other part which means there is a strong negative interaction (shown by - -).



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Correlation Matrix

custo

mer

evalu

atio

n

cap base shoulder

material profil


importance

% s

ilica

% f

lexi

bili

ser

quota

of

tread

deepe

nin

gs

tread

depth

de

nsety

hard

ness

angle

hard

ness

custo

mer

evalu

atio

n

rain capable 5

1 2 3 4 5 6


prosperties1

low noise 3



high durability 3

sportive handling 1

15% 10% 7% 6mm0,8

kg/dm390

o

Shore A10

o 85o

Shore A

1

2

34

56

69 75 94 78 51 43 6 10

7 8 10 8 6 5 1 1


target values

absolute importance

importance 1-10

- - + +

+qualit

y-

chara

cte

ristics

Customer requirements

importance

% s

ilica

% f

lexib

iliser

quota

of

tread

deepenin

gs

tread

depth

densety

hard

ness

angle

hard

ness

rain capable 5

good emergency runningproperties 1

low noise 3



high durability 3

sportive handling 1

...

...

...

...

...

...

...

...

Absolute importance

Importance 1-10Q

ualit

y

chara

cte

ristics

5 x + 3 x + 4 x + 3 x =

5 x 9 + 3 x 1 + 4 x 3 + 3 x 3 = 69

69 75 94 78 51 43 6 107 8 10 8 6 5 1 1

Symbols are used for documenting the correlation between Customer Requirements and Quality Characteristics in the matrix. Three intensity levels are distinguished when using the tabular description.

A circle with a dot in the middle represents for a very strong correlation. For the calculation of the characteristic importance a numeric value of 9 is used.

A medium strong correlation is represented by simple circles (value: 3).

Triangles are used to point out a weak correlation (value: 1).

Usually the correlations are determined during a discussion of experts from all concerned business divisions like design, planning, construction, manufacturing, assembly and quality assurance. According to that only a relatively rough gradation can be used when evaluating the correlations. The term “intensity of correlation” is comparable to the same term, which is used in the fields of statistics.

Than the absolute and the relative importance can be calculated. The absolute importance is calculated by summing up the product of the weight and the value of correlation within a column. The relative importance can be calculated analogue to the calculation of the weight used for the pair wise comparison. (See next page)

Exercise: Calculate the absolute and relative importance of the quality characteristics.



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This page stays empty for technical reasons

A strong correlation exists, if the change of a Quality Characteristic leads to a systematic change of the customer satisfaction (in the sense of the fulfilment of a certain Customer Requirement).

The algorithm for calculating the absolute importance of Quality Characteristics can be described as the following:

Importance of the first Customer Requirement (CR#1) multiplied with the correlation to the first Quality Characteristic (QC#1) plus the importance of CR#2 multiplied with the correlation to QC#1 plus CR#3 x QC#1 plus .... This proceeding has to be repeated for every column (quality characteristic).

The relative importance is calculated analogue to the pair wise comparison :

i = column j = row

Gj = weight of Customer Requirement

Bij = strength of correlation with Quality Chrateristic



Wi : weighting; Si : sum of correlating line; Smax : maximum line sum;

Smin : minimum line sum

+

−

−⋅= 19

minmax

min

AA

AARdW i

i

+

−

−⋅= 14

minmax

min

AA

AARdW i

i

( )ij

n

j

ji BGA ⋅=∑=1



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Benchmark - customer evaluation

- - + +

+

custo

mer

evalu

atio

n

cap base shoulder

material profil


importance

% s

ilica

% f

lexi

bili

ser

quota

of

tread

deepe

nin

gs

tread

depth

de

nsety

hard

ness

angle

hard

ness

custo

mer

evalu

atio

n

rain capable 5

1 2 3 4 5 6


prosperties1

low noise 3



high durability 3

sportive handling 1

15% 10% 7% 6mm0,8

kg/dm3

90o

Shore A10

o 85o

Shore A

12

345

669 75 94 78 51 43 6 10

7 8 10 8 6 5 1 1


target values

absolute importance

importance 1-10


Importance C

usto

mer

evalu

ation

rain capable 5 ... 1 2 3 4 5 6

good emergency runningproperties 1 ...

low noise 3 ...

low fuel consumption 4 ...

high-speed capable 1 ...

high durability 3 ...

sportive handling 1 ...

Benchmark Customer View – Technical View

An additional goal of using QFD in product planning is to determine target values for a detailed development. For this purpose the Quality Characteristics and the Customer Requirements have to be analysed accurately by regarding realisation aspects and their respective market potential.

The way which is usually taken to find out a solution is to compare products directly (benchmarking) and to survey customers about how the regarded products fulfil their requirements.

So the HoQ has to be completed by a customer based and a technical based comparison. Such comparisons in QFD mostly use an integer scale from 1 (“particularly well“ resp. “fulfilled“) to 6 (“particularly bad“ resp. “not fulfilled“). The results of a customer survey and a technical comparison are displayed above and on the following page.



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Benchmark - technical evaluation

custo

mer

evalu

atio

n

cap base shoulder

material profil


importance

% s

ilica

% f

lexi

bili

ser

quota

of

tread

deepe

nin

gs

tread

depth

de

nsety

hard

ness

angle

hard

ness

custo

mer

evalu

atio

n

rain capable 5

1 2 3 4 5 6


prosperties1

low noise 3



high durability 3

sportive handling 1

15% 10% 7% 6mm0,8

kg/dm390

o

Shore A10

o 85o

Shore A

1

2

34

56

69 75 94 78 51 43 6 10

7 8 10 8 6 5 1 1


target values

absolute importance

importance 1-10

- - + +

+qualit

y-

chara

cte

ristics

cap base shoulder

material profil

% s

ilica

% f

lexib

ilise

r

qu

ota

of

tre

ad

de

ep

en

ing

s

tre

ad

de

pth

de

nsity

ha

rdn

ess

an

gle

ha

rdn

ess

...

...

...

...

...

...

...

...

15% 10% 7% 6mm0,8

kg/dm3

90o

Shore A10

o 85o

Shore A

1

2

3

4

5

6

Technical evaluation

Target values



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Process planning cap – third phase (ASI)

Importance 1 - 10

Target values

8Tread depth

10Quota of tread deepenings

8% Flexibiliser

7% Silica

Absolute importance

Vulc

aniz

ing

furn

ace

Extr

uder

Ble

nder

Imp

ort

an

ce

� �

� �

� �

� �

16297135

6 1 10

Process Steps

Quality

Characteristics

Process planning

The HoQ of process planning determines the correlation between process steps and Quality Charactericsof the components.

Analogue to the very first HoQ it is not possible to set up target values or the direction of improvement. Hence filling in the rooftop matrix is not feasible.



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Production planning extruder – fourth phase (ASI)

Absolute importance

Target values

8tread depth

10quota of tread deepenings

8% flexibiliser

7% silica

Direction of improvement

conveyor

belt

speed

wid

thof

die

heig

htof

die

revs

tem

pera

ture

Imp

ort

an

ce

� � �

� � �

�

� � �

80°C70/ min

15mm �

25mm/s

87 15 82 54 72

��

--

++

�

200mm

10

Importance 1 - 10 10 2 9 54 81

Setting Parameter

Quality

Characteristics

Production planning

The production planning provides the correlation between the setting parameters and the Quality Characteristics of the components. This HoQ can be filled in completely. Another thinkable possibility might be to combine the third and fourth house in only one House of Quality.



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Attachments for Exercise 07



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KX

X/X

.03

1 rubber 38%

(natural- and synthetic rubber)

2 fillers 30%

(soot, silica, chalk, ...)

3 reinforcements 16%

(steel, rayon, polyester, nylon)

4 flexibiliser (oil, resin, ...) 10%

5 vulcanising materials

(sulphur, zinc oxide, ...) 4%

6 several chemicals 1%

(wax, antioxidants, ...)

7 miscellaneous 1%

Tyre materials

source: Continental AG



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KX

X/X

.03

The structure of a tyre

Cap: tread and mixture influence the characteristics

Base: cuts the rolling resistance

Nylon overlays: increase the high speed capability

Steel belt: increases the driving stability

Carcass: relevant for form and stability of the tyre

Inner layer: gas proof inner layer replaces the tube

Side frame: protects carcass against damaging and atmos-pheric influences

Core profile: used for steering precision and driving stability. Influences the comfort

Core: ensures a solid fit on the rim

Chipper: for precise steering and a high driving stability source: Continental AG



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conventional tyre

rubber/rubber-contact of the side causes a

fast destruction of the tyre.

RFT tyre

TPMS

Inserts

Insert-profiles in the side panel carry the

load in case of loss of pressure und avert

the rubber / rubber-contact.

Run Flat Tyres (RFT)




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1/2 tread pattern

3 nylon overlays

4 steel belt

synthetic- and natural rubber mixtures

Cap ensures grip, abrasion resistance, driving

stability and stopping performance

Base reduces the rolling resistance

Shoulder constitutes an optimal transition from the

tread pattern to the side panel

rubber covered nylon

ensures high speed stability

steel belt of high tensile strength

ensures form- and driving stability

reduces the rolling resistance

increases the driving performance

Tyre components and their function




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6 inner layer

Rubber covered rayon or polyester

ensures dimensional stability and averts inflation

butyl rubber mixture

ensures airproofness

nature rubber mixtures

Influences the driving comfort

protects against lateral damages

averts ageing damages (ozone, UV-radiation)

5 fabric layer

7 side frame





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8 core profile

9 core

10 chipper

synthetic rubber mixture

ensures driving stability

increases the precision of steering

Influences the driving comfort

rubber covered steel wire

ensures tight fit on the rim

Rubber covered rayon or nylon

ensures driving stability

increases the precision of steering

ensures durability





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Fabrication of tyres


inner layercalendering

tread pattern-extrusion

woven textilecalendering

Core winding

tread pattern-cut

layer-cut

belt-cutbead filler-

application

rubber chemicalsMixing facilities

Steel beltcalendering

side frame-extrusion

carcass-manufacture

blank-manufacture

visualinspection

uniformity measuring

heating

Documents

Exercise Quality Management - wzl.rwth-aachen.de · Time until pizza is delivered: Question: Less than 30 min.? Answer: That's normal. Question: More than 30 min.? ... Quality Function