Design & Manufacturing of Materials Product design:Product development; design core; market analysis and competitive benchmarking; product design specification;

Design & Manufacturing of Materials

Product design: Product development; design core; market analysis and competitive benchmarking; product design specification; concept design; detail design.

Materials selection: Development of materials performance indices with and without shape, materials selection maps, case studies of materials selection: oars, springs, pressure vessels, etc.; selection with multiple constraints.

Process selection: Process selection charts, case studies of a fan, ceramic valve; process costs and cost breakdown.

Manufacturing industry: Plant location; plant layout; critical path analysis; production scheduling; materials requirement planning; Just in Time management.

Metal forming in the packaging industry:

Forming limit diagrams; R-curves; forming processes (e.g. deep drawing); Strain path analysis.

6 Lectures, Trinity Term 20032nd year Materials: Engineering Applications of Materials

Dr Ian Stone (5 lectures) & Dr Paul Butler (1 lecture)

Synopsis

Further Reading

S. Pugh Total Design, Addison-Wesley, 1991 (56PUG)

M.F. Ashby & D.R.H. Jones Engineering Materials 1, Pergamon, 1980 (50ASH/1)

M.F. Ashby & D.R.H. Jones Engineering Materials 2, Pergamon, 1986 (50ASH/2)

M.F. Ashby Materials Selection in Mechanical Design, Butterworth & Heinemann, 1992 (56ASH/1)

B. Derby, D.A. Hills & C. Ruiz

Materials for Engineering, Wiley 1992 (50DER)

E.J. Anderson The Management of Manufacturing, Addison-Wesley, 1994 (56AND)

Product Development

Product Development TeamMarketing Provides market assessment

Identifies market opportunities

Manufacturing Assesses production processAssesses manufacturing costs and quality

Design Defines product form and functionEngineering DesignIndustrial Design

Product Development TypeDevelopment time 1-10 years depending on product

Development cost $100k-$5B depending on product

Development type Generic/Market pullTechnology pushTechnology platformProcess limitedCustomised

Company InnovationLarge companies vs SMEs (small and medium size enterprises)

Product Development Team

Finance

Sales

Legal

ManufacturingEngineer

TEAMLEADER

MarketingProfessional

IndustrialDesigner

PurchasingSpecialist

MechanicalDesigner

ElectronicsDesigner

Extended Team(including suppliers)

Product Development TypeGeneric(Market Pull)

Technology Push

Platform Products

Process Intensive

Customization

Description The firm begins with a market opportunity, then finds an appropriate technology to meet customer needs.

The firm begins with a new technology, then finds an appropriate market.

The firm assumes that the new product will be built around the same technological subsystem as an existing product.

Characteristics of the product are constrained by the production process.

New products are slight variations of existing configurations.

Distinctions with respect to the generic process

Additional initial activity of matching technology and market.

Concept development assumes a given technology.

Concept development assumes a technology platform.

Both process and product must be developed together from the very beginning, or an existing production process must be specified from the beginning.

Similarity of projects allows for a highly structured development process.

Development is almost like a production process.

Examples Sporting goods, furniture, tools.

Gore-Tex rainwear, Tyvek envelopes.

Consumer electronics, computers, printers.

Snack foods, cereal, chemicals, semiconductors.

Switches, motors, batteries, containers.

Product Development ExamplesStanley Tools

Jobmaster screwdriver

Rollerblade Bravoblade In-

Line Skates

Hewlett-Packard

DeskJet 500 Printer

Chrysler Concorde Car

Boeing 777 Aeroplane

Annual production volume

100,000units/year

100,000units/year

1.5 millionunits/year

250,000units/year

50units/year

Sales lifetime 40 years 3 years 3 years 6 years 30 years

Sales price $3 $200 $365 $19,000 $130 million

Number of unique components

3 35 200 10,000 130,000

Development time 1 year 2 years 1.5 years 3.5 years 4.5 years

Internal development team size

3people

5people

100people

850people

6,800People

External development team size

3people

10people

100people

1400people

10,000People

Development cost $150,000 $750,000 $50 million $1 billion $3 billion

Production investment

$150,000 $1 million $25 million $600 million $3 billion

Innovation in Firms

Number of employees

1945-9

(%)

1950-4

(%)

1955-9

(%)

1960-4

(%)

1965-9

(%)

1970-4

(%)

1975-80

(%)

Total

(%)

1-199 16 12 11 11 13 15 17 14

200-499 9 6 8 6 7 9 7 7

500-999 3 2 7 5 5 4 3 4

1,000-9,999 36 36 25 27 23 17 14 23

10,000 and over

36 44 50 51 52 55 59 52

Total 100 100 100 100 100 100 100 100

Number of Innovations

94 191 274 405 467 401 461 2293

Total Design Market Assessment

Specification

Concept Design

Detail Design

Manufacture

Sell

is a systematic activity: Identification of the market need → sale of product to meet that need.Product, Process, People, Organization, etc.

Design CoreMarket AnalysisSpecificationConcept DesignDetailed DesignManufacturingSales

Product Design Specification (PDS)Envelopes all stages of the design core

THE DESIGN CORE

The Design Core Market Assessment

Specification

Concept Design

Detail Design

Manufacture

Sell

MARKETASSESSMENT

Interviews, Questionnaires, Focus Groups

Intellectual Property and Literature Searches

Competitive Benchmarkingparametric analysis, needs matrix

Market Analysis: Example 1

Tristar 333

A rough terrain telescopic handler with parallel lift

Market Analysis: Tristar 333

Market Analysis: Example 2

Microm 160

A microscope manipulator for opthalmology

No.

Make and Model

Feature and function

CO

OP

ER

VIS

ION

ZE

ISS

(J) SL

IT L

A.

ZE

ISS

UN

IVE

RS

AL

WIL

D M

S-C

WIL

D M

S-B

WIL

D M

S-F

WE

CK

10

10

8

WE

CK

(CE

ILIN

G)

AM

SC

O,

AM

SC

OP

E

KE

EL

ER

K-3

80

FW

ZE

ISS

E.M

. C

EIL

ING Graphical

representation of percentage

%

1 Coaxial illumination xxxxxx 54

2 Moto. vert. course movement xxxxxx 54

3 Moto. vert. fine movement xx 18

4 X-Y attachment xxxxxxx 64

5 Motorized zoom (microscope) xxxxxxxxxxx 100

6 Motorized zoom (arm) xxx 27

7 Auto. step magnification xxxxxxxx 73

8 Hand switch controls xxxxxxxxxx 82

9 Mouth switch 0

10 Foot switch xxxxxxxxxxx 100

11 Counterbalanced by weight x 9

12 Counterbalanced by spring xxxxxx 54

13 Energized locking xx 18

14 Friction locking xxxxxxxxx 82

15 Stepped locking xxx 27

16 Rotation free around stand xxxxxxxxxxx 100

MATRIX ANALYSIS

No.

Make and Model

Feature and function

CO

OP

ER

VIS

ION

ZE

ISS

(J) SL

IT L

A.

ZE

ISS

UN

IVE

RS

AL

WIL

D M

S-C

WIL

D M

S-B

WIL

D M

S-F

WE

CK

10

10

8

WE

CK

(CE

ILIN

G)

AM

SC

O,

AM

SC

OP

E

KE

EL

ER

K-3

80

FW

ZE

ISS

E.M

. C

EIL

ING Graphical

representation of percentage

%

17 Vert. course mov. of assembly

xxxxxx 55

18 Course mov. in horiz. plane xxxxxxxxxxx 100

19 Vertical mov. of the arm xxxxxx 55

20 Tilt of microscope attachment xxxxxxxxxxx 100

21 Rotation of micros. attachm. xxxxxx 55

22 Yaw of micros. attachment xxxx 35

23 Connection facil. for attachm. xxxxxxxxxx 91

24 Stand levelling facilities x 9

25 Stand braking facilities xxxxxx 55

26 Fibre optic illumination xxxxxxx 64

27 Down limiting stop xxxxx 45

28 Manual step magnification xxxxxxxx 73

29 Slit illumination xxxxxxx 64

30 Manual zoom 0

31 Horiz. mov. on plane of arms xxxx 36

32 Floor mounted xxxxxxx 63

MATRIX ANALYSIS cont’d


Specification

Concept Design

Detail Design

Manufacture

Sell

SPECIFICATION

Product Design Specification (PDS)

Develop Specification (8 stages)1. Construct customer needs matrix2. Develop performance measures3. Cross correlate (needs-measures matrix)4. Construct competitive benchmark chart to

assess market position (based on customer needs and performance measures)

5. Define an initial set of target specifications6. Carry out engineering design analysis to assess

technical feasibility7. Develop a bill of materials for initial cost

assessment8. Redefine the set of specifications

Product Design Specification (PDS)PatentsEnvironment

Materials

Shelf life

Packing

Competition

Weight

Disposal

Shipping

Size

Processes

Customer

Timescale

Ergonomics

Aesthetics

Installation

Performance

Service life

Quantity

Safety

Testing

Legal

Maintenance

Politics

Plant

Standards

Quality assurance Storage

DESIGN CORE

Partial PDSPatentsEnvironment

Materials

Shelf life

Packing

Competition

Weight

Disposal

Shipping

Size

Processes

Customer

Timescale

Ergonomics

Aesthetics

Installation

Performance

Service life

Quantity

Safety

Testing

Legal

Maintenance

Politics

Plant

Standards

Quality assurance Storage

DESIGN CORE

Element to be considered:

In

Out

For individual components, sub-assemblies, different stages of the design core.

Design Specification: Stage 1

No. Need Importance(1-5)

1 The product must ….. 4

2 The product is ….. 5

3 The product allows ….. 3

4 The product can ….. 1

5 The product lasts ….. 5

etc. etc. etc.

Stage 1: Customer needs matrix


MetricNo.

NeedNos.

Metric Importance(1-5)

Units

A 1,2 Cost 5 £

B 2 Total mass 5 kg

C 3 Compatibility 3 list

D 4 Assembly time 1 s

E 5 Fatigue life 5 cycles

etc. etc. etc. etc. etc.

Stage 2: Develop performance measures


A B C D E

METRIC

NEED

Cost

Total m

ass

Com

patibility

Assem

bly time

Fatigue life

1 The product must …..

2 The product is …..

3 The product allows …..

4 The product can …..

5 The product lasts …..

Stage 3: Cross correlate (needs-measures matrix)


No. Need Importance(1-5)

Comp1

Comp2

Comp3

Comp4

1 The product must ….. 4 x xxx xx xxxx

2 The product is ….. 5 xxx xxxx x xxx

3 The product allows ….. 3 xx xx xxxx x

4 The product can ….. 1 xxxxx x x xx

5 The product lasts ….. 5 xx xxx xxx xxxx

etc. etc. etc. etc. etc. etc. etc.

Stage 4: Construct competitive benchmark chart to assess market position (based on customer needs)

Design Specification: Stage 4 cont’d

MetricNo.

NeedNos.


Units Comp1

Comp2

Comp3

Comp4

A 1,2 Cost 5 £ 60 80 70 90

B 2 Total mass 5 kg 2.3 2.2 2.5 2.3

C 3 Compatibility 3 list w,x w,y w,x,y,z w

D 4 Assembly time 1 s 70 90 90 85

E 5 Fatigue life 5 cycles 22k 23k 23k 24k

etc. etc. etc. etc. etc. etc. etc. etc. etc.

Stage 4: Construct competitive benchmark chart to assess market position (based on performance measures)


MetricNo.

NeedNos.


Units MarginalValue

IdealValue

A 1,2 Cost 5 £ <80 <60

B 2 Total mass 5 kg <2.4 <2.2

C 3 Compatibility 3 list w w,x,y,z

D 4 Assembly time 1 s <90 <70

E 5 Fatigue life 5 cycles >23k >24k

etc. etc. etc. etc. etc. etc. etc.

Stage 5: Initial set of target specifications


Fatigue Model

Geometry

Materials Properties

Fastening Methods

Surface finish

Cycles to Failure

DESIGN MODELS(Model Inputs)

METRICS(Model Outputs)

Stage 6: Engineering design analysis to assess technical feasibility


Component Qty/Part High

(£ ea.)

Low

(£ ea.)

High Total

(£/Part)

Low Total

(£/Part)

Handle

Subframe

Housing

Seal

Bolt

Nut

Assembly @ £10/hr

Overhead @25% of direct cost

2

1

1

1

4

4

5.00

35.00

25.00

1.50

0.30

0.15

6 mins

3.50

28.00

18.00

1.00

0.20

0.10

4 mins

10.00

35.00

25.00

1.50

1.20

0.60

1.00

18.58

7.00

28.00

18.00

1.00

0.80

0.40

0.67

13.97

TOTAL 92.88 69.84

Stage 7: Develop a bill of materials for initial cost assessment


MetricNo.

NeedNos.


Units Value

A 1,2 Cost 5 £ <70

B 2 Total mass 5 kg <2.3

C 3 Compatibility 3 list w,x,y

D 4 Assembly time 1 s <80

E 5 Fatigue life 5 cycles >24k

etc. etc. etc. etc. etc. etc.

Stage 8: Refined set of specifications

ExampleNo. Need Importance

1 The suspension reduces vibration to the hands. 3

2 The suspension allows easy traversal of slow, difficult terrain. 2

3 The suspension enables high-speed descents on bumpy trails. 5

4 The suspension allows sensitivity adjustment. 3

5 The suspension preserves the steering characteristics of the bike. 4

6 The suspension remains rigid during hard cornering 4

7 The suspension is lightweight. 4

8 The suspension provides stiff mounting points for the brakes. 2

9 The suspension fits a wide variety of bikes, wheels and tyres. 5

10 The suspension is easy to install. 1

11 The suspension works with mudguards. 1

12 The suspension instils pride. 5

13 The suspension is affordable for an amateur enthusiast. 5

14 The suspension is not contaminated by water. 5

15 The suspension is not contaminated by mud and dirt. 5

16 The suspension can be easily accessed for maintenance. 3

17 The suspension allows easy replacement of worn parts. 1

18 The suspension can be maintained with readily available tools. 3

19 The suspension lasts a long time. 5

20 The suspension is safe in a crash. 5

Stage 1: Customer needs matrix

A Mountain Bike Suspension Fork

MetricNo.

NeedNos.

Metric Imp. Units

A 1,3 Attenuation from dropout to handlebar at 10 Hz 3 dB

B 2,6 Spring preload 3 N

C 1,3 Maximum value from the Monster test 5 g

D 1,3 Minimum descent time on test track 5 s

E 4 Damping coefficient adjustment range 3 Ns/m

F 5 Maximum travel (26 in. wheel) 3 mm

G 5 Rake offset 3 mm

H 6 Lateral stiffness at the tip 3 kN/m

I 7 Total mass 4 kg

J 8 Lateral stiffness at brake pivots 2 kN/m

K 9 Headset sizes 5 in

L 9 Steertube length 5 mm

M 9 Wheel sizes 5 list

Stage 2: Develop performance measures

MetricNo.

NeedNos.

Metric Imp. Units

N 9 Maximum tyre width 5 in

O 10 Time to assemble to frame 1 s

P 11 Mudguard compatibility 1 list

Q 12 Instils pride 5 subj.

R 13 Unit manufacturing cost 5 US$

S 14 Time in spray chamber without water entry 5 s

T 15 Cycles in mud chamber without contamination 5 k-cycles

U 16,17 Time to disassemble/assemble for maintenance 3 s

V 17,18 Special tools required for maintenance 3 list

W 19 UV test duration to degrade rubber parts 5 hours

X 19 Monster test cycles to failure 5 cycles

Y 20 Japan Industrial Standards test 5 pass/fail

Z 20 Bending strength (frontal loading) 5 kN

Stage 2: Develop performance measures (cont’d)

METRIC

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

NE

ED

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

Stage 3: Cross correlate (needs-measures matrix)

No. Need Imp.

STTritrack

Maniray2

RoxTahx

Quadra

RoxTahxTi 21

TonkaPro

GunhillHeadShox

1 reduces vibration to the hands. 3 x xxxx xx xxxxx xx xxx

2 allows easy traversal of slow, difficult terrain. 2 xx xxxx xxx xxxxx xxx xxxxx

3 enables high-speed descents on bumpy trails. 5 x xxxxx xx xxxxx xx xxx

4 allows sensitivity adjustment. 3 x xxxx xx xxxxx xx xxx

5 preserves the steering characteristics of the bike. 4 xxxx xx x xx xxxxxxxx

6 remains rigid during hard cornering 4 x xxx x xxxxx x xxxxx

7 is lightweight. 4 x xxx x xxx xxxx xxxxx

8 provides stiff mounting points for the brakes. 2 x xxxx xxx xxx xxxxxxx

9 fits a wide variety of bikes, wheels and tyres. 5 xxxx xxxxx xxx xxxxx xxx x

10 is easy to install. 1 xxxx xxxxx xxxx xxxx xxxxx x

11 works with mudguards. 1 xxx x x x x xxxxx

12 instils pride. 5 x xxxx xxx xxxxx xxx xxxxx

13 is affordable for an amateur enthusiast. 5 xxxxx x xxx x xxx xx

14 is not contaminated by water. 5 x xxx xxxx xxxx xx xxxxx

15 is not contaminated by mud and dirt. 5 x xxx x xxxx xx xxxxx

16 can be easily accessed for maintenance. 3 xxxx xxxxx xxxx xxxx xxxxx x

17 allows easy replacement of worn parts. 1 xxxx xxxxx xxxx xxxx xxxxx x

18 can be maintained with readily available tools. 3 xxxxx xxxxx xxxxx xxxxx xx x

19 lasts a long time. 5 xxxxx xxxxx xxxxx xxx xxxxx x

20 is safe in a crash. 5 xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx

Stage 4: Construct competitive benchmark chart to assess market position (based on customer needs)

Specification: A Mountain Bike Suspension Fork

MetricNo.

NeedNos.

Metric Imp Units STTritrack

Maniray2

RoxTahx

Quadra

RoxTahxTi 21

TonkaPro

GunhillHeadShox

A 1,3 Attenuation from dropout to handlebar at 10 Hz

3 dB 8 15 10 15 9 13

B 2,6 Spring preload 3 N 550 760 500 710 480 680

C 1,3 Maximum value from the Monster test

5 g 3.6 3.2 3.7 3.3 l.7 3.4

D 1,3 Minimum descent time on test track 5 s 13 11.3 12.6 11.2 13.2 11

E 4 Damping coefficient adjustment range

3 Ns/m 0 0 0 200 0 0

F 5 Maximum travel (26 in. wheel) 3 mm 28 48 43 46 33 38

G 5 Rake offset 3 mm 41.5 39 38 38 43.2 39

H 6 Lateral stiffness at the tip 3 kN/m 59 110 85 85 65 130

I 7 Total mass 4 kg 1.409 1.385 1.409 1.364 1.222 1.100

J 8 Lateral stiffness at brake pivots 2 kN/m 295 550 425 425 325 650

K 9 Headset sizes 5 in 1.0001.125

1.0001.1251.250

1.0001.125

1.0001.1251.250

1.0001.125

N/A

L 9 Steertube length 5 mm 150180210230255

140165190215

150170190210

150170190210230

150190210220

N/A

Stage 4: Construct competitive benchmark chart to assess market position (based on performance measures)

MetricNo.

NeedNos.

Metric Imp Units STTritrack

Maniray2

RoxTahx

Quadra

RoxTahxTi 21

TonkaPro

GunhillHeadShox

M 9 Wheel sizes 5 list 26 in 26 in 26 in 26 in

700C

26 in 26 in

N 9 Maximum tyre width 5 in 1.5 1.75 1.5 1.75 1.5 1.5

O 10 Time to assemble to frame 1 s 35 35 45 45 35 85

P 11 Mudguard compatibility 1 list Zefal none none none none all

Q 12 Instils pride 5 subj. 1 4 3 5 3 5

R 13 Unit manufacturing cost 5 US$ 65 105 85 115 80 100

S 14 Time in spray chamber without water entry

5 s 1300 2900 >3600 >3600 2300 >3600

T 15 Cycles in mud chamber without contamination

5 k-cycles 15 19 15 25 18 35

U 16,17 Time to disassemble/assemble for maintenance

3 s 160 245 215 245 200 425

V 17,18 Special tools required for maintenance

3 list hex hex hex hex long hex hex, pin wrench

W 19 UV test duration to degrade rubber parts

5 hours >400 250 >400 >400 >400 250

X 19 Monster test cycles to failure 5 cycles >500k >500k >500k 480k >500k 330k

Y 20 Japan Industrial Standards test 5 pass/fail pass pass pass pass pass pass

Z 20 Bending strength (frontal loading) 5 kN 5.5 8.9 7.5 7.5 6.2 10.2

Stage 4: Construct competitive benchmark chart to assess market position (based on performance measures) (cont’d)

MetricNo.

NeedNos.

Metric Imp Units MarginalValue

Ideal Value

A 1,3 Attenuation from dropout to handlebar at 10 Hz 3 dB >10 >15

B 2,6 Spring preload 3 N 480-800 650-750

C 1,3 Maximum value from the Monster test 5 g <3.5 <3.2

D 1,3 Minimum descent time on test track 5 s <13.0 <11.0

E 4 Damping coefficient adjustment range 3 Ns/m 0 >200

F 5 Maximum travel (26 in. wheel) 3 mm 35-50 45

G 5 Rake offset 3 mm 37-45 38

H 6 Lateral stiffness at the tip 3 kN/m >65 >130

I 7 Total mass 4 kg <1.4 <1.1

J 8 Lateral stiffness at brake pivots 2 kN/m >325 >650

K 9 Headset sizes 5 in 1.0001.125

1.0001.1251.250

L 9 Steertube length 5 mm 150170190210

150170190210230

M 9 Wheel sizes 5 list 26 in 26 in

700C

Stage 5: Initial set of target specifications

MetricNo.

NeedNos.

Metric Imp Units MarginalValue

Ideal Value

N 9 Maximum tyre width 5 in >1.5 >1.75

O 10 Time to assemble to frame 1 s <60 <35

P 11 Mudguard compatibility 1 list none all

Q 12 Instils pride 5 subj. >3 >5

R 13 Unit manufacturing cost 5 US$ <85 <65

S 14 Time in spray chamber without water entry 5 s >2300 >3600

T 15 Cycles in mud chamber without contamination 5 k-cycles >15 >35

U 16,17 Time to disassemble/assemble for maintenance 3 s <300 <160

V 17,18 Special tools required for maintenance 3 list hex hex

W 19 UV test duration to degrade rubber parts 5 hours >250 >450

X 19 Monster test cycles to failure 5 cycles >300k >500k

Y 20 Japan Industrial Standards test 5 pass/fail pass pass

Z 20 Bending strength (frontal loading) 5 kN >6 >10

Stage 5: Initial set of target specifications (cont’d)

Assess Technical Feasibility

Dynamic Model ofSuspension Performance

(Analytical)

Suspended Mass

Unsprung Mass

Orifice Diameter

Spring Constant

Oil Viscosity

Attentuation at 10 Hz

Estimated Monster g’s

Static Model ofBrake Mounting Stiffness

(Analytical)

Support Geometry


Tube Geometry

Mounting Points

Lateral Stiffness

Fatigue Model ofSuspension Durability

(Physical)

Fork Geometry


Fastening Methods

Suspension Geometry

Cycles to Failure

DESIGN MODELS(Model Inputs)

METRICS(Model Outputs)

Stage 6: Engineering design analysis to assess technical feasibility

Component Qty/fork High($ ea.)

Low($ ea.)

High Total($/fork)

Low Total($/fork)

Steer tubeCrownBootLower tubeLower tube top coverMain lip sealSlide bushingSlide bushing spacerLower tube plugUpper tubeUpper tube top capUpper tube adjustment knobAdjustment shaftSpringUpper tube orifice capOrifice springsBrake studsBrake brace boltBrake braceOil (litres)Misc. snap rings, o-ringsDecalsAssembly at $20/hrOverhead at 25% of direct cost

TOTAL

1122224222222214221

0.1104

2.504.001.003.002.001.500.200.500.505.503.002.004.003.003.000.500.400.255.002.500.150.25

30 min

2.003.000.752.001.501.400.180.400.354.002.501.753.002.502.250.400.350.203.502.000.100.15

20 min

2.504.002.006.004.003.000.801.001.00

11.006.004.008.006.003.002.000.800.505.000.251.501.00

10.0020.84

$104.19

2.003.001.504.003.002.800.720.800.708.005.003.506.005.002.251.600.700.403.500.201.000.606.67

15.74$78.68

Stage 7: Develop a bill of materials for initial cost assessment

MetricNo.

Metric Units Value

A Attenuation from dropout to handlebar at 10 Hz dB >12

B Spring preload N 600-650

C Maximum value from the Monster test g <3.4

D Minimum descent time on test track s <11.5

E Damping coefficient adjustment range Ns/m >100

F Maximum travel (26 in. wheel) mm 43

G Rake offset mm 38

H Lateral stiffness at the tip kN/m >75

I Total mass kg <1.4

J Lateral stiffness at brake pivots kN/m >425

K Headset sizes in 1.0001.125

L Steertube length mm 150170190210230

M Wheel sizes list 26 in

Stage 8: Refined set of specifications

MetricNo.

Metric Units Value

N Maximum tyre width in >1,75

O Time to assemble to frame s <45

P Mudguard compatibility list Zefal

Q Instils pride subj. >4

R Unit manufacturing cost US$ <80

S Time in spray chamber without water entry s >3600

T Cycles in mud chamber without contamination k-cycles >25

U Time to disassemble/assemble for maintenance s <200

V Special tools required for maintenance list hex

W UV test duration to degrade rubber parts hours >450

X Monster test cycles to failure cycles >500k

Y Japan Industrial Standards test pass/fail pass

Z Bending strength (frontal loading) kN >10.0

Stage 8: Refined set of specifications (cont’d)


Specification

Concept Design

Detail Design

Manufacture

Sell

CONCEPT DESIGN

Concept GenerationClarify problem analyse into sub-problems

determine basic requirementsExternal search interview users, consult

experts,patent search

Internal search brainstorming, analogy, inversion,

staff consultationCombination

Concept AnalysisControlled convergenceRating & weighting method

Concept Design: Car Horn

Concept Design: EvaluationCriterion Concept 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Ease of achieving 105-125 DbA S - + - + + - - - - S +

Ease of achieving 2000-5000 Hz S S N + S S + S - - - S +

Resistance to corrosion, erosion and water - - O S - - S - + - - - S

Resistance to vibration, shock and acceleration S - T S - S - - S - - - -

Resistance to temperature D S - S - - - S S - - S S

Response time A S - E + - - - - S - - - -

Complexity: number of stages T - + V S + + - - - + + - -

Power consumption U - - A + - - + - - - - S +

Ease of maintenance M S + L + + + - - S + + S -

Weight - - U + - - - S - - - - +

Size - - A S - - - - - - - - -

Number of parts S S T + S S - - + - - S -

Life in service S - E + - S - - - - - - -

Manufacturing cost - S D - + + - - S - - - -

Ease of installation S S S S + - S - - - S -

Shelf life S S S S - - S S S S S S

Σ+

Σ-

ΣS

0

6

10

2

9

5

8

1

7

3

9

4

5

7

4

3

12

1

0

11

5

2

8

6

2

13

1

2

13

1

0

8

8

4

9

3

Concept Design: Evaluation/Generation

Initial number of concepts based

on PDS

Initial number reduced

New ones added

Further reduction (FR)

Further addition (FA)

FR

FA

CC

CC

CC

CG

CG

Apply controlled convergence (CC)

Apply concept generation (CC)

CONCEPT SELECTED

Concept Design: Rating & Weighting

Objective

Weight Factor

Rating Rating x Weight Factor

C’pt 1

C’pt 2

C’pt 3

C’pt 4

C’pt 1

C’pt 2

C’pt 3

C’pt 4

Make 20,000 brushes per 8-hour shift

4 5 5 0 5 20 20 0 20

End of brush safety 5 0 5 5 5 0 25 25 25

Ease of manufacture of machine

3 4 0 3 4 12 0 9 12

Reliability of operations

5 4 2 4 4 20 10 20 20

Overall size of machine

2 3 4 3 3 6 8 6 6

Cost 3 3 2 3 3 9 6 9 9

Good filament density 4 3 5 5 5 12 20 20 20

Total 79 89 89 112

Example: Design of a machine to make bottle brushes


Specification

Concept Design

Detail Design

Manufacture

Sell

DETAILDESIGN

Documents

Design & Manufacturing of Materials Product design:Product development; design core; market analysis and competitive benchmarking; product design specification;