quality function deployment -...
TRANSCRIPT
R i c h a r d S . C o w a n , P h . D. , P. E . C h r i s t o p h e r S a l d a n a , P h . D.W o o d r u f f S c h o o l o f M e c h a n i c a l E n g i n e e r i n gG e o r g i a I n s t i t u t e o f T e c h n o l o g yA t l a n t a , G e o r g i a U S A
Quality Function DeploymentFunctions (Actions)
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Specifications: Performance/engineering requirements that product must meet or exceed.
Specifications sheet:• Indicates changes to engineering requirements• Indicates importance of the engineering requirement (demand or wish)• Provides a quantifiable requirement (unit and value, or standard)• Assigns responsibility• Provides source justification (standard, calculation, report, survey, etc.)
Connection to HOQ / QFD
Specification List2
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Specification List3
Issued: Specification
for:
Page 1 Changes D/W Requirements Resp. Source
Replaces issue of
D = Demand W = Wish
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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 Deployment are Sources Of Specifications
Coffee Example4
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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
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“
“““
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“““
Replaces Issue Of
Coffee Specifications #1: “What?” 5
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1. Geometry• Size, height, breadth, length, diameter, space requirement, number, arrangement,
connection extension2. Kinematics
• Type of motion, direction of motion, velocity, acceleration3. Forces
• Direction of force, magnitude of force, frequency, weight, load, deformation, stiffness, elasticity, stability, resonance
4. Energy• Output, efficiency, loss, friction, ventilation, state, pressure, temperature, heating,
cooling, supply, storage, capacity, conversion
Specification Listing6
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5. Material• Physical and chemical properties of the initial and final product, auxiliary material, prescribed
materials (food regulations, etc.)
6. Signals• Inputs and outputs, five senses, form, display, control equipment
7. Safety• Direct safety principles, protective systems, operational, operator and environmental safety
8. Ergonomics• Person-machine relationship, type of operation, cleanliness of layout, lighting, aesthetics
9. Production• Factory limitations, maximum possible dimensions, preferred production methods, means of
production, achievable quality and tolerance
Specification Listing7
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10. Quality control• Possibilities of testing and measuring, application of special regulations and
standards11. Assembly
• Special regulations, installation, siting, foundations12. Transport
• Limitations due to lifting gear, clearance, means of transport (height and weight), nature and conditions of dispatch
13. Operation• Quietness, wear, special uses, marketing area, destination (e.g., atmosphere, tropics)
Specification Listing8
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14. Maintenance• Servicing intervals (if any), inspection, exchange and repair, painting, cleaning
15. Recycling• Reuse, reprocessing, waste disposal, storage
16. Costs• Maximum permissible manufacturing costs, cost of tooling, investment and
depreciation, market price17. Schedules
• End date of development, project planning and control, delivery date
Specification Listing9
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Next Level Of Detail In Specs...10
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
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1st HoQ from class
NIST STD1st HoQ from class
“
Replaces issue of
Coffee Specifications #2: “How?”
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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 Specs12
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Coffee Specifications #3: “How Much?”
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Task Clarification Conceptual Design
Function TreeA tool for describing what a system should do (objectives) in a solution-neutral
fashion; Used for generating ideas and documenting existing ideas for search.
Morphological Matrix/ChartA tool for systematically generating multiple solutions to each planned function
of a system; used for mapping out a design space to explore.
Both of these tools use functional decomposition.
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Functional Decomposition (Action)
describes a desired system (e.g., product) in terms of functions* and sub-functions for both documentation and concept generation.
*Functions: actions or services that are performed.
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Guidelines for Functional Modeling
Consider what’s being done, not how• Draw a box• Identify a verb• Identify a noun(s) on which the verb acts
Follow flows of Energy, Material, and Information/signals. Break the function down as finely as needed• Fine enough to address customer needs• Fine enough for a single basic solution principle to satisfy each sub-function.
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Define overall functionIdentify system boundariesIdentify flows of Energy (E), Material (M), and Information (I)Identify interfacing objects that exchange E, M, or I
Black Box Models
EMI
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Function Block Diagram
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Test Specimen (Force
Deformation)
E load
(M) Specimen
E deformation
(M) Specimen deformed
I force
I deformationI
Change energy into
force & movement
Measure force
Measure deformation
Load specimen
I F
I ∆
E load
I
Specimen E deformation
Specimen deformed
Function Block DiagramExample 1: Material Testing Machine
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Change energy into
force & movement
Measure force
Measure deformation
Load specimen
I F
I ∆
E load
I
SpecimenE deformation
Specimen deformed
Hold specimen
Adjust energy flow
Compare target with actual
values
Amplify measurements
E auxil.
I F target
I ∆ target
E loss
Function Block DiagramExample 1: Material Testing Machine
21Courtesy: Kristin Wood
Function Block DiagramExample 2: Hot air Popcorn Popper
22Courtesy: Kristin Wood
FUNCTION DIAGRAM
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Functional Variants
Shape DoughShaped Dough
ElossDoughAdditives
I
E
1 2 3 54 6
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1 2 3+4 5 6
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Feed in1
Prepare2
Dispense3
Shape4
Separate5
Feed Out6
Return7
Dough ShapedDough
Waste Waste WasteAdditives
1 2 3+4+5 6
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1 2+3 4+5 6
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Overall function and function structure variants of a dough-shaping machine for the manufacture of biscuits (with respect of the main flow only)
Example 3: Dough Shaping Machine
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Function Tree
Function
SF1 SF2 SF3
SF11 SF12 SF13 SF21 SF22 SF23 SF31 SF32 SF33
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Elements• List critical functions and sub-functions.• Sub-branches from a function or sub-function must
number 2 or greater.• Do not specify specifications that are dependent on a
design decision.
Describing this figure in text• Describe the contents, not the tool itself!• What are critical functions?
Summary – Function Tree
See Ch. 3 in book for detail