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2.8 - Materials processing and selection
2 - Ashby Method
Outline
• Processes classification and their attributes
• Steps of selection
• Material-process-shape relations
• Processes selection: Screening and ranking
• Cost modelling: Resource-based approach
• Case study
Resources:
• M. F. Ashby, “Materials Selection in Mechanical Design” Butterworth Heinemann, 1999
Chapter 11
• The Cambridge Material Selector (CES) software -- Granta Design, Cambridge
(www.grantadesign.com)
Processes selection
• Process selection depends on material and shape
• Process attributes are used as criteria for selection
Processes classification
Primary processesCreate
shapes
Secondary processesModify
shapes
Processes classification: Primary processes
CASTING
In casting, a liquid is poured into a mould where it solidifies by cooling (metals) or by reaction(thermosets).
Casting is distinguished from moulding, by the low viscosity ofthe liquid: it fills the mould by flow under its own weight (gravity casting) or under a modest pressure (centrifugal casting and pressure die casting).
Processes classification: Primary processes
MOULDING
Moulding is casting, adapted to materials which are very viscous when molten, particularlythermoplastics and glasses.
The hot, viscous fluid is pressed or injected into a die under considerable pressure, where it cools and solidifies.
Processes classification: Primary processes
DEFORMATION PROCESSING
Deformation processing can be hot, warm or cold. The high temperature lowers the yield strength and allows simultaneous recrystallization, both of which lower the forming pressures.
Extrusion, hot forging and hot rolling have much in common with moulding, though the material is a true solid not a viscous liquid.
Processes classification: Primary processes
POWDER METHODS
Powder methods create the shape by pressing and then sintering fine particles of the material.
The powder can be cold-pressed and then sintered (heated at up to 0.8Tm to give bonding); it can be pressed in a heated die (‘die pressing’); or, contained in a thin preform, it can be heated undera hydrostatic pressure (‘hot isostatic pressing’).
Metals and ceramics which are too high-melting to cast and too strong to deform can be made (by chemical methods) into powders and then shaped in this way.
Processes classification: Primary processes
SPECIAL METHODS
Special methods include techniques which allow a shape to be built up atom-by-atom, as inelectro-forming and chemical and physical vapour deposition.
They include, too, various sprayforming techniques in which the material, melted by direct heating, is sprayed onto a former -- processes which lend themselves to the low-number production of small parts, made from difficult materials.
Processes classification: Secondary processes
MACHINING
Almost all engineering components, whether made of metal, polymer or ceramic,are subjected to some kind of machining or grinding (a sort of micro-machining) during manufacture.To make this possible they should be designed to keep the symmetry high: symmetric shapes need fewer operations.
Metals differ greatly in their machinability: ease of formation, ability to give a smooth surface, and to give economical tool life.
Processes classification: Other processes
JOINING
Joining is made possible by a number of techniques.
Bolting and riveting, welding, brazing and soldering are commonly used for metals.
Polymers are joined by snap-fasteners, and by thermal bonding.
Ceramics can be diffusion-bonded to themselves, to glasses and to metals.
Improved adhesives give new ways of bonding all classesof materials.
Processes classification: Other processes
FINISHING
Finishing describes treatments applied to the surface of the component or assembly.
They include polishing, plating, anodizing and painting, they aim to improve surface smoothness, protect against corrosion, oxidation and wear, and to enhance appearance.
Plating and painting are both made easier by a simple part shape with largely convex surfaces.
HEAT TREATMENT
Heat treatment is a necessary part of the processing of many materials.
Age-hardening alloys of aluminium, titanium and nickel derive their strength from a precipitate produced by a controlled heat treatment.
The hardness and toughness of steels is controlled in a similar way: by quenching from the ‘austenitizing’ temperature (about 800°C) and tempering.
Data organisation: Processes
Family
Joining
Shaping
Surfacing
Class
Casting
Deformation
Moulding
Composite
Powder
Machining
Rapid prototyping
Member
Compression
Rotation
Injection
RTM
Blow
Attributes
A process record
Material
Shape
Size Range
Min. section
Tolerance
Roughness
Economic batch
Supporting information
-- specific
-- general
Material
Shape
Size Range
Min. section
Tolerance
Roughness
Economic batch
Supporting information
-- specific
-- general
Structured
information
Unstructured
information
Difficult !
Kingdom
Processes
Structured data for Injection Moulding
INJECTION MOULDING of thermoplastics is the equivalent of pressure die casting of metals. Molten polymer is injected under high pressure into a cold steel mould. The polymer solidifies under pressure
and the moulding is then ejected.
Injection moulding (Thermoplastics)
Process CharacteristicsDiscrete TruePrototyping False
ShapeCircular Prism True
Non-circular Prism True
Solid 3-D TrueHollow 3-D True
Physical AttributesMass range 0.01- 25 kg
Roughness 0.2 - 1.6 µm
Section thickness 0.4 - 6.3 mmTolerance 0.1 - 1 mm
Economic AttributesEconomic batch size 1e+004 - 1e+006
Relative tooling cost high
Relative equipment cost high
+ links to materials
Unstructured data for Injection Moulding
Design guidelines. Injection moulding is the best way to mass-produce small, precise, plastic parts with complex shapes. The surface finish is good; texture and pattern can be moulded in, and fine detail reproduces well. The
only finishing operation is the removal of the sprue.
The economics. Capital cost are medium to high; tooling costs are high, making injection moulding economic only for large batch-sizes (typically 5000 to 1 million). Production rate can be high particularly for small mouldings. Multi-
cavity moulds are often used. The process is used almost exclusively for large volume production. Prototype mouldings can be made using cheaper single cavity moulds of cheaper materials. Quality can be high but may be traded off against production rate. Process may also be used with thermosets and rubbers.
Typical uses. The applications, of great variety, include: housings, containers, covers, knobs, tool handles,
plumbing fittings, lenses, etc.
The environment. Thermoplastic sprues can be recycled. Extraction may be required for volatile fumes. Significant dust exposures may occur in the formulation of the resins. Thermostatic controller malfunctions can be
extremely hazardous.
The process. Most small, complex plastic parts you pick
up – children’s toys, CD cases, telephones – are injection moulded. Injection moulding of thermoplastics is the equivalent of pressure die casting of metals. Molten
polymer is injected under high pressure into a cold steel mould. The polymer solidifies under pressure and the
moulding is then ejected.
Various types of injection moulding machines exist, but the most common in use today is the reciprocating screw machine, shown schematically here. Polymer granules
are fed into a spiral press like a heated meat-mincer where they mix and soften to a putty-like goo that can be forced
through one or more feed-channels (“sprues”) into the die.
Heater Screw
Granular PolymerMould
Nozzle
Cylinder
N o.8-CMYK-5/01
*Using the CES EduPack Level 2 DB
Steps of selection: Materials
Screening, using constraintseliminate materials which can’t to the job
Ranking, using objectivesfind materials which do the job best
All materials
Subset of materials
Structured
data
Further Information :search “family history” of candidates
Shortlist of candidates
Unstructureddata
Steps of selection: Processes
Screening, using constraintseliminate processes which can’t to the job
Ranking, using cost indicesfind processes which do the job economically
All processes
Subset of processes
Structured
data
Further Information :search “family history” of candidates
Shortlist of candidates
Unstructureddata
Ranking using cost indices is an efficient criterion for first selection of processes.
Screening using constraints derived from requirements: material class, shape class, process attributes.
Steps of selection: Processes
Step 2 Screening: eliminate processes that cannot do the job
Step 3 Ranking: find the processes that do the job most cheaply
Step 4 Supporting information: explore pedigrees of top-ranked candidates
Step 1 Translation: express design requirements as constraints & objectives
� Process selection has the same 4 basic steps
Because there are thousands of variants of processes,
supporting information plays a particularly important role
Process selection has the same 4 basic steps
Step 1: Translate design requirements
From which we obtain …
• Screening criteria expressed as numerical limits on process attribute-values
Or expressed as requirements for material, shape, ….
• Ranking criteria based on indices that characterise
the economic performance
Design concept
Analyse: Function What must the process do? (Shape? Joint? Finish?)
Objective(s) What is to be maximised or minimised? (Cost? Time? Quality?)
Constraints What material, shape, size, tolerance, etc. must it treat or provide?
Free variables Which variables are free? (Choice of process? Process chain options?)
Step 1: Translate design requirements
Example: casing for a road-pressure sensor
Function Casing for road-pressure sensor
Constraints Material: Al alloy
Shape: non-circular prismaticMinimum section: 2 0.025 mm
Objectives Minimise cost
Free variable Choice of process
The sensor lies across the road, covered by a rubber mat. Vehicle pressure deflects
top face, changing capacitance between topface and copper conducting strip.
±
Shaping (primary process)
Step 2: Screening by material, process and shape relations
MATERIALS
SHAPES
PROCESSES
• Ceramics• Glasses• Polymers
• Metals• Elastomers• Composites• Natural materials
• Axisymmetric• Prismatic• Flat sheet
• Dished sheet• 3-D solid• 3-D hollow
• Deformation• Moulding• Powder methods
• Casting• Machining• Composite forming• Molecular methods
Step 2: Screening by material, process and shape relations
Step 2: Screening by material, process and shape relations
Some processes can make only simple shapes, others, complex shapes.
� Wire drawing, extrusion, rolling, shape rolling:
prismatic shapes
All shapes
Prismatic Sheet 3-D
Circular Non-circular Flat Dished Solid Hollow
� Casting, molding, powder methods:
3-D shapes
� Stamping, folding, spinning, deep drawing:
sheet shapes
Step 2: Screening by material, process and shape relations
Step 2: Screening by material, process and shape relations
Step 2: Screening by processes attributes
Step 3: Ranking by economic criteria
The influence of many of the inputs to the cost of a process are captured by a single attribute: the economic batch size.
The easy way to introduce economy into the selection is to rank candidate processes by economic batch sizeand retain those which are economic in the range required.
Step 3: Ranking by economic criteria
The economic batch size is commonly cited for processes.
A process with an economic batch
size with the range B1 - B2 is one which is found by experience to be competitive in cost whenthe output lies in that range.
Example: Process for a spark-plug insulator
• Material class Alumina
• Shape class 3-D, hollow
• Mass 0.05 kg
• Min. section 3 mm
• Tolerance < 0.5 mm
• Roughness < 100 µµµµm
• Batch size >1,000,000
Constraints
Specification
Function Insulator
Free
variables Choice of process
Insulator
Bodyshell
Central
electrode
Objective Minimise cost
Example: Process for a spark-plug insulator
Tree stage: Select CERAMIC (or Alumina)
Rank: bar chart for ECONOMIC BATCH SIZE.
Limit stage: Physical attributes Minimum Maximum
Mass range 0.6 kg
Section thickness mm
Tolerance mm
Roughness µm
Shape
Circular prismatic
Non-circular prismatic
Flat sheet
Dished sheet
Solid 3-D
Hollow 3-D
0.05 0.06
3
bbbb
0.5
100
Example: Process for a spark-plug insulator
Desired Batch Size
Ec
on
om
ic b
atc
h s
ize
(u
nits
)
1
10
100
1000
10000
100000
1e+006
1e+007
1e+008
Blow Moulding
Powder methods
Inject ion Moulding
Sheet forming
Die Casting
Compre ssion M oulding
Expanded foam molding
Rotational
Moulding
Rolling and forging
Resin transfer
molding (RT M)
Electro-discharge machining
Thermoforming Rapid prototyping
Lay-Up
methods
Sand cast ing
Polymer Casting
Economic batch size
To evaluate the competitiveness in cost of a process, depending on the batch size, it is necessary to develop a suitable cost model.
Cost estimation and modelling
Cost estimation and modelling
� Cost estimate for competitive bidding -- absolute cost is wanted, to 3%±
� Cost estimate for ranking -- a relative cost is sufficient – need generality
Cost estimation for purposes of competitive bidding requires precision: profit margins are often less than 10%; an error of a few % can spell disaster.
Cost estimation for ranking of choice – our purpose here – requires only relative values, allowing the conclusion that one process is more or less
expensive than another. That means the model can be approximate, but it
must be broad, to allow comparison between different process families.
Cost modelling: Resource-based approach
Manufacturing
process
Materials
Energy
Capital
Time
Space
Product
All of these have an associated cost
Generic inputs to any manufacturing process
The cost model requires inputs that are common to all families of process.
Each input has an associated cost. The cost of one unit of output is the sum of the contributions from each of these.
• Capital includes the cost of production equipment and tooling.• Time includes labor and administration and other overheads.• Information includes R&D costs or royalty and other payments to the
originator of the process, if they exist.
Information
Cost modelling: Resource-based approach
Resource-based approach
The manufacture of a component consumes resources.
The process cost is the sum of the costs of the resources it consumes.
n = batch size
n = batch rate.
Cost modelling: Resource-based approach
Resource-based approach
The manufacture of a component consumes resources.
The process cost is the sum of the costs of the resources it consumes.
n = batch size
n = batch rate.
Cost modelling: Resource-based approach
Resource-based approach
The manufacture of a component consumes resources.
The process cost is the sum of the costs of the resources it consumes.
n = batch size
n = batch rate.
Cost modelling: Resource-based approach
Resource-based approach
The manufacture of a component consumes resources.
The process cost is the sum of the costs of the resources it consumes.
n = batch size
n = batch rate.
Cost modelling: Resource-based approach
1 0
10 0
100 0
1000 0
1.E+00 1.E+01 1.E+02 1 .E+0 3 1 .E+0 4 1 .E+0 5
Batch size (units)
Co
st
per
un
it (
$/u
nit
)Material and process A
Material and process C
Material and process B
Tooling costs
dominate
Material and labor costs dominate
n
C
n
CCC
L.grosstm
&
&
++= *
Meaning of “economic batch size”
Cost modelling: Resource-based approach
Input information sources
� Web sources
• American Metal Market On-line, www.amm.com• Iron & Steel Statistics Bureau, www.issb.co.uk• Kitco Inc Gold & Precious Metal Prices, www.kitco.com/gold.live.html - ourtable
• London Metal Exchange, www.lme.co.uk
• Metal Bulletin, www.metalbulletin.plc.uk• Mineral-Resource, minerals.usgs.gov/minerals
• The Precious Metal and Gem Connection, www.thebulliondesk.com/default.asp
� Ask suppliers
� Material and process costs vary with time
and depend on the quantity you order
� CES has approximate cost for 2900 materials and 80 processes
Thomas Register of European Manufacturers, TREM
Thomas Register of North American Manufacturers
www.tremnet.com
Cost modelling in CES
Materials Tooling
Batch size
( )
+∑
+
∑+
−= oh
wo
ctm Ct.L
C
n
1
n
C
f1
CmC &
&
Rate of production
Capital, Labor, Information, Energy...
Material costs Cm per kg, and a mass m is used per unit;
f is the scrap fraction (the fraction thrown away) f1
Cm m
−
Tooling Ct is “dedicated” -- it is written off against the number of parts to be made, n n
Ct
Capital cost Cc of equipment is “non-dedicated”
It is written off against time, giving an hourly rate.
The write-off time is two . The rate of production is units/hour.
The load factor (fraction of time the equipment is used) is L.n&
wo
c
t.L
C
n
1
&
The gross overhead rate contributes a cost per unit of time
that, like capital, depends on production rate oh
C&
n& n
Coh
&
&
Cost modelling in CES
Cost of equipment Cc
Cost of tooling Ct
Production rate
Characteristics of the process
The database has approximate value-ranges for thesen&
++
+
−= oh
wo
ctm Ct.L
C
n
1
n
C
f1
CmC &
&
Cost modelling in CES
Batch size n
Mass of component m
Material cost Cm
Capital write-off time tw o
Load factor L
Overhead rate ohC&
Site-specific, user defined parameters
These are entered by the user via a dialog box
Cost of equipment Cc
Cost of tooling Ct
Production rate
Characteristics of the process
The database has approximate value-ranges for thesen&
++
+
−= oh
wo
ctm Ct.L
C
n
1
n
C
f1
CmC &
&
Cost modelling in CES
Cost modelling
Relative cost index (per unit) 5 - 6
Capital cost 2000 - 5000 GBP
Material utilisation factor 0.7 - 0.75
Production rate (units) 20 - 30 per hr.
Tooling cost 300 - 450 GBP
Tooling life 5000 - 10000 units
fx
Dialog box
Capital write-off time two = ….
Component mass m = ….
Load factor L = ….
Material cost Cm =
Overhead rate = ….ohC&
Batch SizeMaterial Cost=2GBP/kg, Com ponent
1 100 10000 1e+006 1e+008
Cost Index (per unit) (G
BP)
10
100
1000
10000
Re
lati
ve
co
st
Batch size
Graph
Case
Rotor
Burst shield
Case study: Flywheels
Specification for a flywheel
Specification
Flywheel
Maximum energy/weight
• Must not disintegrate
• Cost within reason
• Fr. Toughness adequate
• Material
Function
Objectives
Constraints
Free variables
Multiple constraints problem (Overconstrained)
Primary constraint Performance maximizing criteria
Material index and constraints for flywheels
• Maximise energy/unit weight at maximum velocity
Energy
Mass
Must not fail
Energy/mass
Angular velocity
πρ=Ι
ωΙ=
2
tR
2U
42
ρπ= tRm 2
( )y
22R8
3σ≤ωρ
ν+=σ
( )
≈
ν+
ρ
σ≈
2
1
8
3
2m
U y
Density
Strength
Moment of inertia
(1)
(2)
(3)
(4)
Material index and constraints for flywheels
• Maximise energy/unit weight at maximum velocity
Energy
Mass
Must not fail
Energy/mass
Maximise
ρ
σ=
yM
Angular velocity
πρ=Ι
ωΙ=
2
tR
2U
42
ρπ= tRm 2
( )y
22R8
3σ≤ωρ
ν+=σ
( )
≈
ν+
ρ
σ≈
2
1
8
3
2m
U y
Density
Strength
Moment of inertia
Additional constraint: Fracture toughness > 10 MPa.m1/2
(1)
(2)
(3)
(4)
Material for flywheels
ρyσM=
1 Ceramics: But fracture toughness inadequate
2 CFRP, GFRP: The best choice
The selection2
1
Material for flywheels
Density (typical) (Mg/m^3)
1 10
Ela
stic
Lim
it (t
ypic
al)
(M
Pa
)
10
10 0
10 00
CFRPGFRP
Low alloy ste els
Mg alloys
Nickel alloys
Coppe r alloys
Zinc alloys
Low carbon stee l
Al alloys
Al-SiC Composite
Ti alloys
Lead alloys
Density (Mg/m3)
Strength - DensityAdditional constraint:
K1c > 15 MPa.m1/2
Str
eng
th (
MP
a)
ρyσM=
Searchregion
Results
CFRP
• ρ= 1,5 Mg/m3
• σy = 1000 GPa
• m = 0,34 Mg
• M = σy/ρ = 660 MPa.m3/Mg
• Cm = 85 euro/Kg
GFRP
• ρ= 1,8 Mg/m3
• σy = 700 GPa
• m = 0,41 Mg
• M = σy/ρ = 390 MPa.m3/Mg
• Cm = 15 euro/Kg
ρπ= tRm 2
R = 0,5 m t = 0,3 m
Processes selection
CFRP
• ρ= 1,5 Mg/m3
• σy = 1000 GPa
• m = 0,34 Mg
• M = σy/ρ = 660 MPa.m3/Mg
• Cm = 85 euro/Kg
GFRP
• ρ= 1,8 Mg/m3
• σy = 700 GPa
• m = 0,41 Mg
• M = σy/ρ = 390 MPa.m3/Mg
• Cm = 15 euro/Kg
Injection moulding
Compression moulding
Cost modelling: Main parameters
CFRP
• m = 0,34 Mg
• Cm = 85 euro/Kg
GFRP
• m = 0,41 Mg
• Cm = 15 euro/Kg
Component length
Component mass
Material cost
Overhead rate
Capital write-off time
Load factor
0,3 m
0,34 Mg
85 euro/kg
60 euro/h
5 years
0,5
0,3 m
0,41 Mg
15 euro/kg
60 euro/h
5 years
0,5
Cost evaluation: Analysis of results
Cost evaluation: Analysis of results
Cost evaluation: Analysis of results
Cost evaluation: Analysis of results
Cost evaluation: Analysis of results
Cost evaluation: Analysis of results
4000 units
Cost evaluation: Analysis of results
Cost evaluation: Analysis of results
Selecting joining and surface treatment processes
Process
records
Heat treat
Paint/print
Coat
Polish
Texture ...
Electroplate
Anodise
Powder coat
Metallize...
Material
Purpose of treatment
Coating thickness
Surface hardness
Relative cost ...
Supporting information
Material
Purpose of treatment
Coating thickness
Surface hardness
Relative cost ...
Supporting information
Adhesives
Welding
Fasteners
Braze
Solder
Gas
Arc
e -beam ...
Material
Joint geometry
Size Range
Section thickness
Relative cost ...
Supporting information
Material
Joint geometry
Size Range
Section thickness
Relative cost ...
Supporting information
Class AttributesMember
Surface
treat
Joining
Family
Shaping
Kingdom
Processes
Selecting joining and surface treatment processes
Gas Tungsten Arc (TIG)Tungsten inert-gas (TIG) welding, the third of the Big Three (the
others are MMA and MIG) is the cleanest and most precise, but also the most expensive. In one regard it is very like MIG
welding: an arc is struck between a non-consumable tungsten electrode and the work piece, shielded by inert gas (argon, helium, carbon dioxide) to protect the molten metal from
contamination. But, in this case, the tungsten electrode is not consumed because of its extremely high melting temperature.
Filler material is supplied separately as wire or rod. TIG welding works well with thin sheet and can be used manually, but is easily automated.
Physical AttributesComponent size non-restricted
Watertight/airtight TrueProcessing temperature 870 - 2250 K
Section thickness 0.7 - 8 mm
Joint geometryLap True
Butt TrueSleeve True
Scarf TrueTee True
Materials Ferrous metals
Economic AttributesRelative tooling cost low
Relative equipment cost mediumLabor intensity low
Typical usesTIG welding is one of the most commonly used processes for dedicated automatic welding in the automobile, aerospace, nuclear, power generation, process plant, electrical and domestic equipment
markets.
+ links to materials
Selecting joining and surface treatment processes
Induction and flame hardeningTake a medium or high carbon steel -- cheap, easily formed and
machined -- and flash its surface temperature up into the austenitic
phase-region, from which it is rapidly cooled from a gas or liquid jet,
giving a martensit ic surface layer. The result is a tough body with a
hard, wear and fatigue resistant, surface skin. Both processes allow the
surface of carbon steels to be hardened with minimum distortion or
oxidation. In induction hardening, a high frequency (up to 50kHz)
electromagnetic f ield induces eddy-currents in the surface of the work-
piece, locally heating it; the depth of hardening depends on the
frequency. In flame hardening, heat is applied instead by high-
temperature gas burners, followed, as before, by rapid cooling. Both
processes are versatile and can be applied to work pieces that cannot
readily be furnace treated or case hardened in the normal way.
Physical AttributesCoating thickness 300 - 3e+003 µm
Component area restricted
Processing temperature 727 - 794 K
Surface hardness 420 - 720 Vickers
Economic AttributesRelative tooling cost low
Relative equipment cost medium
Labor intensity low
Typical usesThe processes are used to harden gear teeth, splines, crankshafts, connecting rods, camshafts, sprockets and gears,
shear blades and bearing surfaces.
MaterialCarbon steel
Purpose of treatmentFatigue resistance
Friction control
W ear resistance
Hardness
+ links to materials
Selecting joining and surface treatment processes
Joining -- the most important criteria are:
� The material(s) to be joined
� The geometry of the joint
Apply these first, then add other constraints
Surface treatment -- the most important criteria are:
� The purpose of the treatment
� The material to which it will be applied
Apply these first,
then add other constraints
Assessing potential: Cost, price and value
Technical performance
Technical performance
Estimates for cost, C
Estimates for cost, C
Potential viability
Is there profit in it?
Potential viability
Is there profit in it?
Market assessment
Value V, adoption time ta
Market assessment
Value V, adoption time ta
Successful implementation
Successful implementation
� The real requirement is
Cost < Price < Value
C < P < V
Cost C = what it actually costs to make the part or product
Price P = the sum you sell it for
Value V = the worth the consumer puts on the product
The ultimate economic objective is not so much to minimize cost as to maximize the difference between cost and value – the worth the consumer perceives the product to have.
If, by using more expensive materials and processes value is increased more than cost, the difference V-C increases, allowing the profit P-C to be maximized.
Assessing potential: Cost, price and value
A product has a cost C the true cost of manufacture, marketing etc.
a price P the price at which it is offered to the consumer
a value V what the consumer thinks it is worth
Product success requires thatC < P < V
What determines cost? Technical design, materials, processes
What determines value? Both technical and industrial design;
-- aesthetics, associations, perceptions
My Parker pens,
8 euros eachParker special
edition 3000 euros
Do they write 375 times better?
Improve potential: Technical, industrial and product design
Technical design
Industrial design
Product design
Aesthetics
Associations
PerceptionsSatis-
factionProduct must be
life-enhancing
UsabilityProduct must be easy
understand and use
FunctionalityProduct must work, be safe, economical
Improve potential: Industrial Design
• As products mature and markets saturate, the products of competing manufacturers converge technically -- hardly differ in performance or cost
ID allows differentiation, enhanced value
Product maturity and market saturation
• Corporate and product identity are partly created and largely maintained through innovative industrial design
ID creates corporate image
Corporate identity
• Products are part of our environment. Products that give no sensual satisfaction damage the environment.
ID contributes to quality of life
The environment, in the broadest sense
Improve potential: Product character
Product “psychology”
Aestheticsassociations
Personalityperceptions
Biometrics
UsabilityBio-mechanics
Product “physiology”
Metals, ceramics
Materialspolymers, composites
Shapingjoining
Processessurface
treatment
Product
“character”What, who
Contextwhere, when
why
Function
ProductFeatures
Assessing potential: Cost, price and value
Market assessment: size Smax and adoption time ta of the potential market
Time (Years)
Ma
rke
t vo
lum
e S
Anticipated volume,
Smax
Adoption
time, ta
Production
starts
Revenue
Investment
Investmentstarts
First +valuecash flow
First
profit
Net cash flow
Ca
sh
flo
w
Time
• Production volume (batch size)
• Cash flow projection
The main points
� To maximize profit: minimize cost C (economics of manufacture) and maximize value V (technical performance and product image)
� Cost can be modeled at several levels -- depends on purpose
� To rank process options, approximate modeling is adequate
� A cost-model for this uses “generic” inputs (Resource-based
approach): material, time, capital etc
� More precise analysis must be based on information from suppliers or (if out-sourcing) contractors.