Design Manufacturing of Materials 2 nd 6

Design & Manufacturing of Materials 2 nd 6 Lectures, Trinity Term 2003 year Materials: Engineering Applications of Materials Dr Ian Stone (5 lectures) & Dr Paul Butler (1 lecture) Synopsis 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.

Further Reading S. Pugh Total Design, Addison-Wesley, 1991 (56 PUG) M. F. Ashby & D. R. H. Jones Engineering Materials 1, Pergamon, 1980 (50 ASH/1) M. F. Ashby & D. R. H. Jones Engineering Materials 2, Pergamon, 1986 (50 ASH/2) M. F. Ashby Materials Selection in Mechanical Design, Butterworth & Heinemann, 1992 (56 ASH/1) B. Derby, D. A. Hills & C. Ruiz Materials for Engineering, Wiley 1992 (50 DER) E. J. Anderson The Management of Manufacturing, Addison. Wesley, 1994 (56 AND)

Product Development Team Marketing Manufacturing Design Provides market assessment Identifies market opportunities Assesses production process Assesses manufacturing costs and quality Defines product form and function Engineering Design Industrial Design Product Development Type Development time Development cost Development type 1 -10 years depending on product $100 k-$5 B depending on product Generic/Market pull Technology push Technology platform Process limited Customised Company Innovation Large companies vs SMEs (small and medium size enterprises)

Product Development Team Manufacturing Engineer Finance Marketing Professional Purchasing Specialist TEAM LEADER Sales Legal Industrial Designer Electronics Designer Mechanical Designer Extended Team (including suppliers)

Product Development Type Generic (Market Pull) Description Technology Push Platform Products Process Intensive Customization 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. Additional initial activity of matching technology and market. 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. Snack foods, cereal, chemicals, semiconductors. Switches, motors, batteries, containers. Distinctions with respect to the generic process Concept development assumes a given technology. Examples Sporting goods, furniture, tools. Gore-Tex rainwear, Tyvek envelopes. Consumer electronics, computers, printers. Development is almost like a production process.

Product Development Examples Stanley Tools Jobmaster screwdriver Rollerblade Bravoblade In. Line Skates Hewlett-Packard Desk. Jet 500 Printer Chrysler Concorde Car Boeing 777 Aeroplane Annual production volume 100, 000 units/year 1. 5 million units/year 250, 000 units/year 50 units/year Sales lifetime 40 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 3 people 5 people 100 people 850 people 6, 800 People External development team size 3 people 100 people 1400 people 10, 000 People 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 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 Number of Innovations 94 191 274 405 467 401 461 2293 Number of employees

Total Design is a systematic activity: Identification of the market need → sale of product to meet that need. Product, Process, People, Organization, etc. Design Core Market Analysis Specification Concept Design Detailed Design Manufacturing Sales Product Design Specification (PDS) Market Assessment Specification Concept Design Detail Design Manufacture Envelopes all stages of the design core Sell THE DESIGN CORE

The Design Core Market Assessment Specification MARKET ASSESSMENT Concept Design Interviews, Questionnaires, Focus Groups Intellectual Property and Literature Searches Competitive Benchmarking parametric analysis, needs matrix Detail Design Manufacture Sell

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

WILD MS-F WECK 10108 WECK (CEILING) AMSCO, AMSCOPE ZEISS E. M. CEILING WILD MS-B KEELER K-380 FW WILD MS-C ZEISS UNIVERSAL Feature and function ZEISS (J) SLIT LA. No. COOPER VISION Make and Model Coaxial illumination 2 Moto. vert. course movement 3 Moto. vert. fine movement 4 X-Y attachment 5 Motorized zoom (microscope) 6 Motorized zoom (arm) 7 Auto. step magnification 8 Hand switch controls 9 Foot switch 11 Counterbalanced by weight 12 Counterbalanced by spring 13 Energized locking 14 Friction locking 15 Stepped locking 16 Rotation free around stand xxxxxx 54 18 xxxxxxx 64 xxxxxx 100 xxx 27 Mouth switch 10 % xx 1 Graphical representation of percentage xxxx 73 xxxxx 82 0 54 xx 9 xxxxxx 100 x xxxxxx 18 xxxxx 82 xxx 27 xxxxxx 100 MATRIX ANALYSIS

Tilt of microscope attachment 21 Rotation of micros. attachm. 22 Yaw of micros. attachment 23 Connection facil. for attachm. 24 Stand levelling facilities 25 Stand braking facilities 26 Fibre optic illumination 27 Down limiting stop 28 xxxxxx 55 xxxxxxxxxxx 100 xxxxxx 55 35 xxxxx 91 x 9 xxxxxx 55 xxxxxxx 64 xxxxx 45 xxxx ZEISS E. M. CEILING 20 KEELER K-380 FW Vertical mov. of the arm AMSCO, AMSCOPE 19 WECK (CEILING) WECK 10108 Course mov. in horiz. plane WILD MS-F 18 WILD MS-B Vert. course mov. of assembly WILD MS-C 17 ZEISS UNIVERSAL Feature and function ZEISS (J) SLIT LA. No. COOPER VISION Make and Model 29 Slit illumination 30 Horiz. mov. on plane of arms 32 Floor mounted % Manual zoom 31 Manual step magnification Graphical representation of percentage xxxx 73 xxxxxxx 64 0 xxxx 36 xxxxxxx 63 MATRIX ANALYSIS cont’d

The Design Core Market Assessment SPECIFICATION Specification Product Design Specification (PDS) Develop Specification (8 stages) 1. Construct customer needs matrix 2. Develop performance measures 3. 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 specifications 6. Carry out engineering design analysis to assess technical feasibility 7. Develop a bill of materials for initial cost assessment 8. Redefine the set of specifications Concept Design Detail Design Manufacture Sell

Product Design Specification (PDS) Environment Patents Shelf life Packing Testing Competition Safety Weight Legal Maintenance Quantity Materials Politics Ergonomics Plant Aesthetics Disposal DESIGN CORE Installation Shipping Size Service life Standards Performance Processes Quality assurance Customer Timescale Storage

Element to be considered: Partial PDS In Environment Patents Out Shelf life Packing Testing Competition Safety Weight Legal Maintenance Quantity Materials Politics Ergonomics Plant Aesthetics Disposal DESIGN CORE Installation Shipping Size Service life Standards Performance Processes Quality assurance Customer Timescale Storage For individual components, subassemblies, 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. Stage 1: Customer needs matrix

Design Specification: Stage 2 Metric No. Need Metric Nos. Importance (1 -5) Units Cost 5 £ A 1, 2 B 2 Total mass 5 kg C 3 Compatibility 3 list D 4 Assembly time 1 s E 5 Fatigue life 5 cycles etc. Stage 2: Develop performance measures

Design Specification: Stage 3 A B C D E Cost Total mass Compatibility Assembly time Fatigue life METRIC NEED 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)

Design Specification: Stage 4 No. Need Importance (1 -5) Comp 1 Comp 2 Comp 3 Comp 4 1 The product must …. . 4 x xx xxxx 2 The product is …. . 5 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 xxxx etc. Stage 4: Construct competitive benchmark chart to assess market position (based on customer needs)

Design Specification: Stage 4 cont’d Metric No. Need Metric Nos. Importance (1 -5) Units Comp 1 Comp 2 Comp 3 Comp 4 Cost 5 £ 60 80 70 90 A 1, 2 B 2 Total mass 5 kg 2. 3 2. 2 2. 5 2. 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 22 k 23 k 24 k etc. etc. Stage 4: Construct competitive benchmark chart to assess market position (based on performance measures)

Design Specification: Stage 5 Metric No. Need Metric Nos. Importance (1 -5) Units Marginal Value Ideal Value Cost 5 £ <80 <60 A 1, 2 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 >23 k >24 k etc. Stage 5: Initial set of target specifications

Design Specification: Stage 6 Geometry Materials Properties Fastening Methods Surface finish DESIGN MODELS (Model Inputs) Fatigue Model Cycles to Failure METRICS (Model Outputs) Stage 6: Engineering design analysis to assess technical feasibility

Design Specification: Stage 7 Component Qty/Part Handle Subframe Housing Seal Bolt Nut Assembly @ £ 10/hr Overhead @25% of direct cost TOTAL High (£ ea. ) Low (£ ea. ) High Total (£/Part) Low Total (£/Part) 2 1 1 1 4 4 5. 00 35. 00 25. 00 1. 50 0. 30 0. 15 6 mins 3. 50 28. 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 1. 00 0. 80 0. 40 0. 67 13. 97 92. 88 69. 84 Stage 7: Develop a bill of materials for initial cost assessment

Design Specification: Stage 8 Metric No. Need Metric Nos. Importance (1 -5) Units Value Cost 5 £ <70 A 1, 2 B 2 Total mass 5 kg <2. 3 Compatibility 3 list w, x, y D 4 Assembly time 1 s <80 E 5 Fatigue life 5 cycles >24 k etc. Stage 8: Refined set of specifications

Example No. Need Importance reduces vibration to the hands. 3 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 Stage 1: Customer needs matrix The suspension 2 A Mountain Bike Suspension Fork 1 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

Metric No. Need Nos. A 1, 3 B Metric Imp. Units Attenuation from dropout to handlebar at 10 Hz 3 d. 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 k. N/m I 7 Total mass 4 kg J 8 Lateral stiffness at brake pivots 2 k. N/m K 9 Headset sizes 5 in L 9 Steertube length 5 mm M 9 Wheel sizes 5 list Stage 2: Develop performance measures

Metric No. Need Nos. N 9 O Metric Imp. Units Maximum tyre width 5 in 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 k. N Stage 2: Develop performance measures (cont’d)

METRIC A 1 8 9 NEED 10 11 12 13 14 15 E F G H I J K L M N O P Q R S T U V W X Y Z 5 7 D 4 6 C 2 3 B 16 17 18 19 20 Stage 3: Cross correlate (needs-measures matrix)

ST Tritrack Maniray 2 Rox Tahx Quadra Rox Tahx Ti 21 Tonka Pro Gunhill Head Shox No. Need Imp. 1 reduces vibration to the hands. 3 x xxxx xx xxx 2 allows easy traversal of slow, difficult terrain. 2 xx xxx xxxxx 3 enables high-speed descents on bumpy trails. 5 x xxxxx xx xxx 4 allows sensitivity adjustment. 3 x xxxx xx xxx 5 preserves the steering characteristics of the bike. 4 xxxx xx xxxx 6 remains rigid during hard cornering 4 x xxxxx 7 is lightweight. 4 x xxx xxxxx 8 provides stiff mounting points for the brakes. 2 x xxx xxxxxxx 9 fits a wide variety of bikes, wheels and tyres. 5 xxxxx x 10 is easy to install. 1 xxxxx xxxxx x 11 works with mudguards. 1 xxx x x xxxxx 12 instils pride. 5 x xxx xxxxx 13 is affordable for an amateur enthusiast. 5 xxxxx xx 14 is not contaminated by water. 5 x xxxx xx xxxxx 15 is not contaminated by mud and dirt. 5 x xxxx xx xxxxx 16 can be easily accessed for maintenance. 3 xxxxx xxxxx x 17 allows easy replacement of worn parts. 1 xxxxx xxxxx x 18 can be maintained with readily available tools. 3 xxxxx xx x 19 lasts a long time. 5 xxxxx xxxxx x 20 is safe in a crash. 5 xxxxx xxxxx Stage 4: Construct competitive benchmark chart to assess market position (based on customer needs)

Specification: A Mountain Bike Suspension Fork Metric No. Need Nos. A 1, 3 B Metric Imp Units ST Tritrack Maniray 2 Rox Tahx Quadra Rox Tahx Ti 21 Tonka Pro Gunhill Head Shox Attenuation from dropout to handlebar at 10 Hz 3 d. B 8 15 10 15 9 13 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 k. N/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 k. N/m 295 550 425 325 650 K 9 Headset sizes 5 in 1. 000 1. 125 1. 250 1. 000 1. 125 N/A L 9 Steertube length 5 mm 150 180 210 230 255 140 165 190 215 150 170 190 210 230 150 190 210 220 N/A Stage 4: Construct competitive benchmark chart to assess market position (based on performance measures)

Metric No. Need Nos. M 9 N Metric Imp Units ST Tritrack Maniray 2 Rox Tahx Quadra 26 in Rox Tahx Ti 21 Wheel sizes 5 list 26 in 9 Maximum tyre width 5 in 1. 5 1. 75 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 all Q 12 Instils pride 5 subj. 1 4 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 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 long hex, pin wrench W 19 UV test duration to degrade rubber parts 5 hours >400 250 >400 250 X 19 Monster test cycles to failure 5 cycles >500 k 480 k >500 k 330 k Y 20 Japan Industrial Standards test 5 pass/fail pass pass Z 20 Bending strength (frontal loading) 5 k. N 5. 5 8. 9 7. 5 6. 2 10. 2 26 in 700 C Tonka Pro 26 in Gunhill Head Shox 26 in Stage 4: Construct competitive benchmark chart to assess market position (based on performance measures) (cont’d)

Metric No. Need Nos. A 1, 3 B Metric Imp Units Marginal Value Ideal Value Attenuation from dropout to handlebar at 10 Hz 3 d. B >10 >15 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 k. N/m >65 >130 I 7 Total mass 4 kg <1. 4 <1. 1 J 8 Lateral stiffness at brake pivots 2 k. N/m >325 >650 K 9 Headset sizes 5 in 1. 000 1. 125 1. 250 L 9 Steertube length 5 mm 150 170 190 210 230 M 9 Wheel sizes 5 list 26 in 700 C Stage 5: Initial set of target specifications

Metric No. Need Nos. N 9 O Metric Imp Units Marginal Value Ideal Value Maximum tyre width 5 in >1. 5 >1. 75 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 W 19 UV test duration to degrade rubber parts 5 hours >250 >450 X 19 Monster test cycles to failure 5 cycles >300 k >500 k Y 20 Japan Industrial Standards test 5 pass/fail pass Z 20 Bending strength (frontal loading) 5 k. N >6 >10 Stage 5: Initial set of target specifications (cont’d)

Assess Technical Feasibility Suspended Mass Unsprung Mass Orifice Diameter Spring Constant Oil Viscosity Dynamic Model of Suspension Performance (Analytical) Support Geometry Materials Properties Tube Geometry Mounting Points Static Model of Brake Mounting Stiffness (Analytical) Lateral Stiffness Fatigue Model of Suspension Durability (Physical) Cycles to Failure Fork Geometry Materials Properties Fastening Methods Suspension Geometry DESIGN MODELS (Model Inputs) Attentuation at 10 Hz Estimated Monster g’s METRICS (Model Outputs) Stage 6: Engineering design analysis to assess technical feasibility

Component Qty/fork Steer tube Crown Boot Lower tube top cover Main lip seal Slide bushing spacer Lower tube plug Upper tube top cap Upper tube adjustment knob Adjustment shaft Spring Upper tube orifice cap Orifice springs Brake studs Brake brace bolt Brake brace Oil (litres) Misc. snap rings, o-rings Decals Assembly at $20/hr Overhead at 25% of direct cost TOTAL High ($ ea. ) Low ($ ea. ) High Total ($/fork) Low Total ($/fork) 1 1 2 2 4 2 2 2 2 1 4 2 2 1 0. 1 10 4 2. 50 4. 00 1. 00 3. 00 2. 00 1. 50 0. 20 0. 50 5. 50 3. 00 2. 00 4. 00 3. 00 0. 50 0. 40 0. 25 5. 00 2. 50 0. 15 0. 25 30 min 2. 00 3. 00 0. 75 2. 00 1. 50 1. 40 0. 18 0. 40 0. 35 4. 00 2. 50 1. 75 3. 00 2. 50 2. 25 0. 40 0. 35 0. 20 3. 50 2. 00 0. 15 20 min 2. 50 4. 00 2. 00 6. 00 4. 00 3. 00 0. 80 1. 00 11. 00 6. 00 4. 00 8. 00 6. 00 3. 00 2. 00 0. 80 0. 50 5. 00 0. 25 1. 50 1. 00 10. 00 20. 84 $104. 19 2. 00 3. 00 1. 50 4. 00 3. 00 2. 80 0. 72 0. 80 0. 70 8. 00 5. 00 3. 50 6. 00 5. 00 2. 25 1. 60 0. 70 0. 40 3. 50 0. 20 1. 00 0. 60 6. 67 15. 74 $78. 68 Stage 7: Develop a bill of materials for initial cost assessment

Metric No. Metric Units Value A Attenuation from dropout to handlebar at 10 Hz d. B >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 k. N/m >75 I Total mass kg <1. 4 J Lateral stiffness at brake pivots k. N/m >425 K Headset sizes in 1. 000 1. 125 L Steertube length mm 150 170 190 210 230 M Wheel sizes list 26 in Stage 8: Refined set of specifications

Metric No. 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 >500 k Y Japan Industrial Standards test pass/fail pass Z Bending strength (frontal loading) k. N >10. 0 Stage 8: Refined set of specifications (cont’d)

The Design Core CONCEPT DESIGN Concept Generation Clarify problem analyse into sub-problems determine basic requirements External search interview users, consult experts, patent search Internal search brainstorming, analogy, inversion, staff consultation Combination Concept Analysis Controlled convergence Rating & weighting method Market Assessment Specification Concept Design Detail Design Manufacture Sell

Concept Design: Car Horn

Concept Design: Evaluation Criterion Concept 1 2 3 Ease of achieving 105 -125 Db. A S - Ease of achieving 2000 -5000 Hz S S Resistance to corrosion, erosion and water - Resistance to vibration, shock and acceleration 4 5 6 7 8 9 10 11 12 13 14 + - + + - - S + N + S S + S - - - S + - O S - - S - + - - - S S - T S - - - S S - - S S Resistance to temperature D 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 - - - Shelf life S S - - S S S 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 0 8 8 4 9 3 Σ+ ΣΣS

Concept Design: Evaluation/Generation Initial number of concepts based on PDS Initial number reduced Apply controlled convergence (CC) Apply concept generation (CC) New ones added CC Further reduction (FR) Further addition (FA) CG CC FR CG FA CC CONCEPT SELECTED

Concept Design: Rating & Weighting Rating x Weight Factor 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 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 79 89 89 112 Objective Total Example: Design of a machine to make bottle brushes

The Design Core Market Assessment Specification DETAIL DESIGN Concept Design Detail Design Manufacture Sell