me 2110 - creative decisions & designsinghose.marc.gatech.edu/courses/me2110 fall08... · ©...
TRANSCRIPT
© 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
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Function
Abstract formulation of the taskIndependent of particular solutionWhat something doesNot how it does itNot what it is made from
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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)
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Car Seat Example
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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
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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
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Phases of Design (Product Lifecycle)
1) Customer RequirementsUnderstand the Problem
2) Specification DevelopmentEngineering Requirements
3) Conceptual Design4) Detail Design5) Specification of Production6) Manufacture7) Recycle
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Specification List(from Functions)
Issued:Specification
for: Page 1Changes D/W Requirements Resp. Source
Replaces issue of
D = Demand W = Wish
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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
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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
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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)
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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
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Pencils
Cumberland Pencil Co., Keswick, England
Original Source
Pencil Manufacturing
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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
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Developing Specifications (Beginning a Spec Sheet)
Issued:Specification
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
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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.
Developing Specifications (Beginning a Spec Sheet)
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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
Developing Specifications (Beginning a Spec Sheet)
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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
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Issued:Specification
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...
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)
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Issued:Specification
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)
Issued:Specification
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
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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 TOSERVINGREINITIALIZE (RENEWFILTER, GROUNDS)
Continue with next level of detail in specs
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Example products so far
1) Cup of Coffee2) Pencil3) Shipyard4) Computer Monitor5) CanSat5) Car Door6) Moving Car Seat
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Pole Vaulting
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Pole Vaulting
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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
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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
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Bend Testing of Poles
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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
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Design Tools at Your Disposal
1) House of Quality-Subcomponents, Problem Understanding Form, etc.
2) Function Trees3) Function Tables4) Specification Lists
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