concept generation

Module SESA2007/SESM2008 ; Engineering

Design

James Scanlan; School of Engineering Sciences

1

Concept Generation


Design


2

Early Design Phase

• Where most innovation potential lies

• Where designer has most freedom

• Where critical decisions are made

• Creativity, lateral/unconventional thinking, rule breaking, important


Design


3

Searching

• Race against time.

• Therefore;

– Need to search quickly.

– Identify shortcuts.

– Balance analytical techniques with

“Engineering Judgement”.

– Use Navigation tools.


Design


4

Conception

Value

Time

Birth

Infancy/Growth

Maturity

Retirement

Typical Product Life-Cycle S-Curve

Source; Darryl Mann http://function.creax.com/

Examples?

Steam Engines

Typewriters

Oil/gas lamps

Floppy discs

Passenger jet!


Design


5

Consequences of Late to

Market

• Fuel burn 6% more than estimated

• Redesign of HPC

• Over 2 years late to market

• Deselected for A318


Design


6

Audit/ approval• Legal obligation

• Audit decision making process

• Challenge and critique

• Need to justify decisions andprocesses

• Need to demonstrate scope of search


Design


7

Navigation tools

In terrestrial navigation generally 2

dimensions and a single unit of

measure.

Design Space; many dimensions

(hyperspace) and many units of

measure.


Design


8

Navigation is a Major Issue

• Detailed priorities unclear in large organisation..

– A380 weight/cost/reliability

trade-off examples


Design


9

Wider Issues• Design organisation under

increasing pressure to embrace wider issues such as

– Environmental issues

– Aesthetics

– Political issues (offset,

workshare)

– Minority, disabled requirements

– Psychological; safety perception


Design


10

Search Space

Initial Concepts

Specification

Outline Schemes

Detail Design Geometry

Increasing

level of detail

Manufacturing Data


Design


11

Search space

Parameter α Parameter β Parameter χ Parameter δ

Part a

Parameter α Parameter β Parameter χ Parameter δ

Part b

Parameter α ..n

Part c

Parameter α ..n

Part d

Assembly a Assembly b Assembly c Assembly d

Concept 1

Parameter α..n

Part a...n

Assembly a

Parameter α ..n

Part a...n

Assembly b

Parameter α ..n

Part a...n

Assembly c

Parameter α ..n

Part a...n

Assembly d

Concept 2

Parameter α ..n

Part a...n

Assembly a...n

Concept 3

Parameter α..n

Part a...n

Assembly a...n

Concept 4

Parameter α ..n

Part a...n

Assembly a...n

Concept 5

DesignEven For a Simple

Product the Potential

Search Space is Vast

Searching is Expensive

Design Methodologies

Ensure That a Search Takes

Place in a Rigorous and

Systematic Manner


Design


12

Search Strategy

• Depth First

• Breadth First

Strengths/

Weaknesses?


Design


13

New Concept Examples

• Radar; use of magnetron in domestic appliances (microwave oven)

• Cyclone used in wood mills applied to vacuum cleaner (James Dyson)

• Failed industrial adhesive used in stationery yellow “Post-it” notes (3M)

• Tensator spring used in wind-up generator (Trevor Bayliss)

• Semi-conductor laser used in data storage devices (CD/DVD)

• High strength magnetic fields led MRI scanners (Oxford Instruments)

• Use of large prime numbers in data encryption

• Use of platinum catalyst in gas powered hair curlers/ portable soldering irons


Design


14TIME

‘VALUE’ = Benefits/(Costs + Penalties)

PRODUCT/PROCESS TRENDING - S-Curves

1st GEN

2nd GEN

3rd GEN…..


Examples; CRT -> Plasma monitorsMechanical Typewriters -> Electric Typewriters-> Word Processors

Steam Engines-> Diesel EnginesIncandescent lamps -> LEDS

Records -> tapes -> CD’s -> MP3

Innovation

Innovation


Design


15

S-Curve Families

* Every single component in the system has its own family of s-curves

* (Every component’s manufacturing process has its own family of s-curves)

* At the lower hierarchy levels, the more likely it is that the designer will design at the top right hand end of the family



Design


16

S-Curve Families

Value

Time

Value

Time

Value

Time

Value

Time

Value

Time

Value

Time

Value

Time

‘Automobile’

Suspension

Transmission

Engine

Piston

Fuel

Injection

Valve

Timing



Design


17

Ideation; concept classification

Degree of difficulty/risk/cost to implement

Eff

ecti

ven

ess/

qu

ali

ty o

f id

ea

EasyDifficult

Outstanding

Good


Design


18

Concept selection

Constraint filter

Ranking tool

Cut-off point


Design


19

Morph ChartsFig 10: External flange concepts and favoured solutions External

Flange

Form

Drain

Attachment

Valve

Attachment

Circular

Symmetry

�Easy to

Prototype

� Bulky

Elongated

�Will sit in skin "fold"

� Less easy to

prototype

Cushioned

Outer

Flange

�Takes up

"slack".

� Cleanability,

Manufacturability

Membrane�Simple

� Single use

"Duck" Valve�Simple

�� Leak prone

Snap-Fit

�Simple

� Wear

Clip�Positive

� Dexterity

Side

Connection

�Low prof ile

� Complexity

Front

Connection

�Simpl

e

Fixed�Low Parts

count

� Failure requires

Ball Valve

�Good Seating

� Cost

Reed valve

�Simple

�� Leak prone

Plate Valve

�Positive

� Poor Seating

Spool Valve

�Positive

� Complex

Direct

�Parts count V

� Bulky Port

Retractable

Lugs �Positive

� Complex

"T-Bar"

��

Positive

Wear

Screw

Attach

�Simple

� Wear

Use

Adaptor

�Flexible

�Extra Part

Hinge clips

�Positive

� Dexterity

Bayonet

Mount�Simple

� Wear

Deformable 'rubber'

& spring


Design


20

Morph ChartsFig : 11 Bladder retention concepts and favoured solutions

Retention

Method

InternalExternal

� Simple to deploy

� Complex.

Retention Force

Over-

Centre

Cage

Stretched

Dome

� Simple

� Retention Force?

Insertion Complexity

Torque

Deployed

Paddles

� Positive

� Complex Portal

Tube, Torque req'd

Trapdoor

Mechanism

� Positive

� Complex

Portal Tube

Skin

Adhesive

/Dressing

� Very Simple

� Need to Re-

apply Daily

Inflatable

Torus

� Proven

� Limited

Life?

Tendon

Methods

� Positive

� Costly, Complex

Sub-

cutaneous

Flange

� Semi-Permanent

� Emergency removal.

Limited No of Re-

insetions.

Body

Piercing

'Studs'

� Semi-permanent

� Emergency removal,

infection prone, semi-

invasive, aesthetics

Snap

Hinge/Spring

Linkage

� Simple to Use

� Retention Force?

Complex to Manufacture

Memory

Alloys

� Positive

� Costly, Complex to

insert/ remove

Hinge

Petals

� Simple to deploy

� Possible low

retention force


Design


21

Summary; concept generation

1. Identify critical issues (conflicts) first.

2. Generate ideas

3. Assess /classify /develop ideas

4. Filter, rank select

5. Develop selected concept/idea(s)

concept generation

Documents

engineering judgement

npart cparameter

npart dassembly

nassembly aparameter

nassembly dconcept

nassembly cparameter

nassembly bparameter

design space