QFD Requirements prioritization J.Jayaraman Center for Aerospace Systems Design and Engineering)...

QFD Requirements prioritization

J.JayaramanCenter for Aerospace Systems Design and Engineering)

Department of Aerospace EngineeringIndian Institute of technology, Bombay

DIAT POINTS COURSE 03-06-2008

Benefits of QFD

JJ DIAT POINTS COURSE 02-06-2008

Comparison of design changes with and without QFD

-14-17-1-3 0 +3 months

Design changes

Jap Co used QFD

US Co Did not use QFD

Toyota production start up problems before and after QFD

-5 -4 -3 -2 -1 0 +1 2 3 4 5

After QFD

Before QFD

Product complaints

months

Benefits of QFD


Pre QFD

startup Pre production

After QFD

startup Pre production

39% of pre QFD cost

Loss

Preparation training etc.

Start up and Pre-production costs at Toyota before and after QFD

Quality Function Deployment (QFD)


•QFD is a concept developed by Yaji Akao•Developed at Kobe shipyard of Mitsubishi Shipyard early 1980s.•Xerox and Ford have used it•Typically applied to small systems. Being tried for large systems (NASA Lunar Rover)•It was developed to build design quality into a product



It facilitates translation of a prioritized set of subjective customer requirements into a set of system level requirements during system conceptual stage

It addresses customer requirements, design requirements, functions, parts, and failure modes



Definition

“ An organized, disciplined process for determining the product or service requirements necessary to achieve customer-perceived expressed or unexpressed quality” (Otten and Groeneveld 2002)



•QFD permits analysis and determination of priority issues

•QFD is a planning process

•Out puts are the key action issues for improved customer satisfaction



Customer Requirements

whats

Customer weights

Relative importance

Design requirements

Hows

Relationship Matrix

Whats vs. hows

Hows vs. hows

Whats vs. whys

whys

How much How much vs. How much

Benchmarking

competition

Prioritized requirements Competitive benchmarks Design targets

QFD provides integration through the life cycle phases

of the system


Customer voice analysisCustomer Requirements

System Design Requirements

Customer importance

Sub-system Requirements

Product design and development

Part requirements

Process requirements

Manufacturing process design and development

Requirements prioritization


Improvement ratio: It is the ratio of desired performance to existing performance

Sales point: It is the weight given to a requirement if it will improve the marketability of the product

Requirements prioritization


Customer weights: The importance customer gives to each of his requirements. It defines his priorities.

Customer satisfaction: It is the rating of the existing product technical characteristics based on the customer requirements

Planned satisfaction: It is the rating of the new product technical characteristics planned based on customer requirements

Determining Target values Design Requirements


Identify customer Requirements (CR) and weight

Identify design requirements (DR) corresponding to CR

Identify relationship between DR and CR

Bench mark competitive products on CR

Determine improvement ratio and revised weights of CR

Calculate weight of DRs

Choose best value of competing DR performance

Video projector Customer requirements and

weightsCR No.

Customer requirements

Customer

weights

1 Excellent image quality

3

2 Clear sound 1

3 Easy to use 9

4 portable 9

5 stylish 1

6 reliable 9

7 quiet 3

8 compatible 9

9 affordable 9

10 Bright image 9

Customer weights scale 1-9

Video projector benchmarking competitors

Customer requirements

Customer weights

Us Product A

Plan IPR Sales point

Raw score

Revised customer weights

Excellent image quality

3 5 7 7 1.4 1.2 5.0 6.0

Clear sound 1 4 5 5 1.2 1.0 1.2 1.4

Easy to use 9 7 6 7 1.0 1.3 11.7 14.0

portable 9 8 6 8 1.0 1.3 11.7 14.0

stylish 1 3 4 3 1.0 1.0 1.0 1.2

reliable 9 7 5 8 1.2 1.3 14.0 16.8

quiet 3 4 5 4 1.0 1.0 3.0 3.6

compatible 9 7 7 7 1.0 1.2 10.8 12.9

affordable 9 7 6 7 1.0 1.1 9.9 11.9

Bright image 9 5 7 7 1.4 1.2 15.1 18.3

IPR- Improvement ratio

Raw score= customer weight*IPR*sales point Revised Customer wt. = Raw score/ Raw score

Video projector design requirements with their

unitsDesign requirements Sl No. Units

Image brightness 1 lumens

Contrast ratio 2 a:1

Image resolution 3 X*Y pixels

weight 4 kg

Set up time 5 seconds

Audio quality 6 N-M Hz.

Audio volume 7 Watts

Physical volume 8 mm*mm*mm

Surface temperature 9 Degree C

Operating noise 10 dB

MTBF 11 Hours`

Video projector Relationship matrix CRs vs. DRs

Rel.wt. % PriorityRel.wt. % Priority

Raw scoreRaw score

11.911.999

18.318.31010

12.912.988

3.63.677

16.816.866

1.21.255

14.014.044

14.014.033

1.41.422

6.06.011

Revised Revised Cust. wts.Cust. wts.

CR CR No.No.

33 11 22 44

23223210510516516527427435353131307307282282109109109109236 236

3333993333333399

331133111133

99

9911111111

993311331111

1133111111

119911111199

1133119933

3311339911

1133999999

11111010998877665544332211

Design requirementsDesign requirements

Video projector Target requirements

50K4550305*230*100

0.850 to 6000

30 4.2.600*450

350:1500Our product

Desig

n

Desig

n

req

uir

em

en

req

uir

em

en

tsts

Imag

e

Imag

e

bri

gh

tness

bri

gh

tness

Con

trast

rati

oC

on

trast

rati

o

Imag

e

Imag

e

resolu

tion

resolu

tion

Weig

ht

Weig

ht

Set

up

tim

e

Set

up

tim

e

Au

dio

qu

ality

Au

dio

qu

ality

Au

dio

volu

me

Au

dio

volu

me

Ph

ysic

al volu

me

Ph

ysic

al volu

me

Su

rface

Su

r face

tem

pera

tur e

tem

pera

ture

Op

era

tin

g

Op

era

tin

g

nois

en

ois

e

MTB

FM

TB

F

40K4060350*250*100

150 to 6000

354.5800* 600

400:1700Product A

50K4050305*230*100

150To6000

304800*600

400:1700Target s



Solve water dispenser problem in place of the video projector

QFD Requirements prioritization J.Jayaraman Center for Aerospace Systems Design and Engineering)...

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