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© GIT 2007 1

Problem DefinitionsSpecifications

ME 2110 - Creative Decisions & Design

Lecture 6 v.1

© GIT 2007 2

Phases of Design (Product Lifecycle)

1) Customer RequirementsUnderstand the Problem

2) Specification DevelopmentEngineering Requirements

3) Conceptual Design4) Detail Design5) Specification of Production6) Manufacture7) Recycle

© GIT 2007 3

Function

Abstract formulation of the taskIndependent of particular solutionWhat something doesNot how it does itNot what it is made from

© GIT 2007 4

Functions & Sub-Functions

World’s coolest monitor –Provide multimedia interaction

Generate sound Record sound Communicatewith computer

SF11 SF12 SF13 SF21 SF22 SF23 SF31 SF32 SF33

(Function Tree)

© GIT 2007 5

Car Seat Example

© GIT 2007 6

Moving Car Seat

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Moving SeatFunctions & Sub-Functions

Provide ActiveSafety

Be Comfortable Move During Crash Reduce Injuries

MaintainShape

Change shape to conform to Human

Body

SenseCrash

FollowDesired

Trajectory

Increase BottomAngle

Prevent Passenger from

Hitting Roof

© GIT 2007 8

Function Table(List Possible Solutions)

Sub-Function \ Solution1 2 ... j ... m

1 SF1 S11 S12 S1j S1m

2 SF2 S21 S22 S2j S2m

...i SFi Si1 Si2 Sij Sim

...n SFn Sn1 Sn2 Snj Snm

Sense Crash

© GIT 2007 9

Phases of Design (Product Lifecycle)

1) Customer RequirementsUnderstand the Problem

2) Specification DevelopmentEngineering Requirements

3) Conceptual Design4) Detail Design5) Specification of Production6) Manufacture7) Recycle

© GIT 2007 10

Specification List(from Functions)

Issued:Specification

for: Page 1Changes D/W Requirements Resp. Source

Replaces issue of

D = Demand W = Wish

© GIT 2007 11

Checklist for Developing a Specification List (1)

Geometry– Size, height, length, diameter, space requirement, number,

arrangement, extension

Kinematics– Type of motion, direction of motion, velocity, acceleration

Forces– Direction of force, magnitude of force, frequency, weight,

stiffness, stability, resonance

Energy– Output, efficiency, loss, friction, ventilation, pressure,

temperature, heating, cooling, storage, capacity

© GIT 2007 12

Spec List Checklist (2)Material

– Physical and chemical properties of initial and final product, auxiliary material, prescribed materials (food regulations, etc.)

Signals– Inputs and outputs, display, control equipment

Safety– Safety principles, protective systems, operator and

environmental safety

Ergonomics– Person-machine relationship, type of operation,

cleanliness of layout, lighting

Production– Factory limitations, maximum possible dimensions,

preferred production methods, means of production, tolerance

© GIT 2007 13

Spec List Checklist (3)

Quality control– Testing and measuring methods, application of special

regulations and standards

Assembly– Special regulations, installation, special foundations

Transport– Limitations due to lifting gear, clearance, means of

transport

Operation– Quietness, wear, intended destination (tropics, moon)

© GIT 2007 14

Spec List Checklist (4)

Maintenance– Servicing intervals (if any), inspection, exchange and

repair, painting, cleaning

Recycling– Reuse, reprocessing, waste disposal, storage

Costs– Maximum manufacturing costs, cost of tooling, investment

Schedules– End date of development, project planning and control,

delivery date

© GIT 2007 15

Pencils

Cumberland Pencil Co., Keswick, England

Original Source

Pencil Manufacturing

© GIT 2007 16

Example: A Pencil

Task: Design a PencilFunctions:– Make an Erasable Mark– Erase an Erasable Mark

Constraints–Can be made into a point–Holds point–Comfortable to use–Cheap–Non-toxic

© GIT 2007 17

Developing Specifications (Beginning a Spec Sheet)


For: A Pencil Page 1Changes D/W Requirements Resp. Source

DW

D

D

DDDDD

Make And Erase Marks On Paper.

GeometryFits In Human HandFits In Pocket

KinematicsQuick

Forces:Operates With Force From A Human

Material:Forms Erasable MarkRemoves Erasable MarkSharpenableHolds A PointNot Poisonous

DesignClass

Instructor“

“

“

StandardProduct

““

FDA

Replaces Issue Of

© GIT 2007 18

Issued: 1 (Cont’d) Page 2Changes D/W Requirements Resp. Source

D

D

DDD

D

WDDD

DD

Signals:Operation Force Changes When

Sharpening NeededOperation Force Changes When

Eraser Needs FixingSafety:

Not PoisonousQuietWill Not Break into Hazardous PiecesNo Sharp Edges

Ergonomics:LightweightComfortableFits In Adult Human HandActivation Force Is Within Human

Limits.Production:

Few PartsEasy

DesignClass Instructor

“

OSHA“““

Instructor“““

Boothroyd &Dewhurst GuideTo Mfg.


© GIT 2007 19

Issued: 1 (Cont’d) Page 3Changes D/W Requirements Resp. Source

D

D

D

DDDD

D

D

D

D

Quality Control:Visual Inspection Only

Assembly:None By Customer

Transport:No Special Requirements, Packaging,

Permits, Etc.Operation:

QuietEasyGood Wear CharacteristicsOperates In Any Environment In Which

Paper Can Be UsedOperates On Any Paper

Maintenance:Easily Sharpened (Re-Pointed)

Costs:Cheap ($0.10 Selling Price)

Schedule:By The End Of Class

Mfg Engineer

Std. Product

Mfg Engineer

Instructor“““

“

“

K-Mart Price

Instructor


© GIT 2007 20

House Of House Of House Of House Of House OfQuality #1 Quality #1 Quality #2 Quality #3 Quality #4

What How / What (#2) How / What (#3) How / What (#4) How

Cust. Req. Characteristic Feature Process Production

Hot Serving Temp. Water Temp. Water Speed ThermometerSmells Good Smell Jury Bean’s Origin Heater Output Flow ControlTastes Good Taste Jury Water Quality Brew Time TimerCheap Price Weight/Serving Brew Temp. Cleaning PlanGood Color Color Std. Fineness Of

Ground.Grind Setting Disposal Plan

(Raw, Brewed)Non-Poisonous Analysis Age Of Coffee Water SourceNo Grounds Filter/Weigh (Raw, Brewed) Filter Quality

Time To ServingReinitialize (Renew Filter, Grounds)

Entries in Houses of Quality from QFD are sources of specifications

Back to Coffee Example

© GIT 2007 21


For: CUP OF COFFEE Page 1

Changes D/W Requirements Resp. SourceCup Of Coffee

EnergyHot

MaterialGood ColorNon-PoisonousNo Grounds

SafetyNon-Poisonous

SignalsGood ColorSmells GoodTastes Good

CostsCheap

Quality ControlGood ColorSmells GoodTastes Good

1st HoQ WHATs fromclass

“““

“

“““

“

“““

Replaces Issue Of

Coffee Specifications #1

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Next level of detail in specs...







Time To ServingReinitialize (Renew Filter,Grounds)

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for: Cup Of Coffee Page 1

Changes D/W Requirements Resp. Source

10/3/9510/3/95

10/3/95

10/3/95

10/3/95

Cup Of Coffee

Energy:Serving Temperature

Material:Color StdNon-PoisonousBrewed Coffee Should Yield Minimum Coffee

Grounds When FilteredSafety:

Non-PoisonousSignals:

Color StdSmells JuryTaste Jury

Costs:Minimize Price

Quality Control:Color StdSmells JuryTaste Jury

1st HoQ from class

NIST STDFDA1st HoQ from class

FDA

NIST STD1st HoQ from class

“

1st HoQ from class

NIST STD1st HoQ from class

“

Replaces issue of

Coffee Specifications #2: “Hows”

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Coffee Specifications #3: “How Much's”(Getting Close to a Spec Sheet)


For: CUP OF COFFEE Page 1

Changes

D/W Requirements Resp. Source

10/4/9510/4/95

10/4/95

10/4/95

10/4/95

Cup Of Coffee

Energy:Serving Temperature, 140 oF

Material:Color Std, NIST # ?Non-Poisonous, < X1, X2, ...mg/lBrewed Coffee Should Yield < Y mg/l Coffee

Grounds When FilteredSafety:

Non-Poisonous, < X1, X2, ...mg/lSignals:

Color Std, NIST # ?Smells Jury, 95% ConsensusTaste Jury, 95% Consensus

Costs:Minimize Price

Quality Control:Color Std, NIST # ?Smells Jury, 95% ConsensusTaste Jury, 95% Consensus

1st Hoq From Class

NIST STDFDA1st HOQ From Class

FDA

NIST STD1st HOQ From Class

Ņ

1st HOQ From Class

NIST STD1st HOQ From Class

ŅReplaces Issue Of

© GIT 2007 26

Example products so far

1) Cup of Coffee2) Pencil3) Shipyard4) Computer Monitor5) CanSat5) Car Door6) Moving Car Seat

© GIT 2007 29

Be Consistent Lightweight Fit Comfortably in Hands

Be LabeledProperly

Constraints

Pole Vault Pole Functions

Shoot Athlete Highinto the Air

(Repeatedly)

Support LoadRelease EnergyAbsorb Energy MaintainStiffnessStore Energy

© GIT 2007 30

Pole Vault Pole Specifications

For: A Pole Vault PoleD/WChanges

Specification

Resp. SourceRequirements

USHSF

Standard

Shoot athlete high into the air

GeometryFits in Human HandRound/Oval Cross Section

KinematicsUnbends Quickly

ForcesBending Force ScalableHigh Breaking Force

MaterialsMoldableDurableDuctileNot temperature dependent

SafetyWill not fracture easilyRepeatable Stiffness

DesignTeam

Standard

USHSF

USHSFStandard

D

D

D

DDD

D

W

W

W

W

D

© GIT 2007 32

Pole Vault Pole Specifications

For: A Pole Vault Pole

D/WChanges

Specification

Resp. SourceRequirements

USHSF

Standard

Shoot athlete 3-6 m into the air.

GeometryDiameter between 1.75”-2.5”Length between 10’8”-17’1”

KinematicsDamping ratio < 0.1

ForcesBending force scalableBending angle > 180 deg.

MaterialsMoldableDurableDuctileNot temperature dependent

SafetyWill not fracture99% stiffness after 5k bends

DesignTeam

Standard

USHSF

USHSFStandard

D

D

D

DDD

D

W

W

W

W

D

© GIT 2007 33

Design Tools at Your Disposal

1) House of Quality-Subcomponents, Problem Understanding Form, etc.

2) Function Trees3) Function Tables4) Specification Lists

me 2110 - creative decisions & designsinghose.marc.gatech.edu/courses/me2110 fall08... · ©...

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