Post on 04-Jan-2016
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Product Design and DevelopmentProduct Design and Development
Final exam review Fall 2011Final exam review Fall 2011
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MULTIPLE CHOICE QUESTIONS
AND SHORT ANSWERS
Multiple choice questions cover all material including detailed design. Make sure you
know good CAD modeling practices, views, dimensioning rules (over dimensioning,
under dimensioning), weld types, differences between part and assembly drawings etc.
Review guest lectures.
4Clearance fit Transition fit Interference fit
ec001.SLDASM
Sample question:
Identify fits A, B, C
hole shaft hole shaft hole shaft
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Line fit
Transition fit
Interference fit
Sample question:
Identify fits A, B, C
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Identify some commonly used features:
Have many sketches they need?
Which one may or may not be the first feature in Feature Manager Design Tree?
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USE SI UNITS ON EXAM
DO NOT CONFUSE UNITS OF MASS AND FORCE
PRICE/COST IS NOT A DESIGN SPECIFICATION
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PRODUCT DESIGN TECHNIQUES - KNOW WHAT ARE THEY
AND WHEN THEY ARE USED
CUSTOMER SURVEY
QUALITY FUNCTION DEPLOYMENT
GANTT’S CHARTS
CRITICAL PATH METHOD
FUNCTIONAL DECOMPOSITION
BRAINSTORMINGMORPHOLOGICAL ANALYSIS
FEASIBILITY JUDGMENT
TECHNOLOGY READINESS ASSESSMENT
GO/NO-GO SCREENING
DECISION MATRIX METHOD
CAD
MATERIAL SELECTION
ENGINEERING MODELS
SIMULATION
DFR
DFM
DFA
RISK ENGINEERING
PRELIMINARY HAZARD ANALYSIS
FAULT TREE ANALYSIS
FAILURE MODES AND EFFECT ANALYSIS
PRODUCT LIFE CYCLE
DESIGN FOR HUMAN FACTORS
DFE
DESING FOR DISASSEMBLY
DESIGN FOR RECYCLING
PATENT SEARCH
FEA
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CUSTOMER SURVEY
QUALITY FUNCTION DEPLOYMENT
GANTT’S CHARTS
CRITICAL PATH METHOD
Specification Development
PRODUCT DESIGN TECHNIQUES - SPECIFICATION DESIGN
Planning Phase
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FEASIBILITY JUDGMENT
TECHNOLOGY READINESS ASSESSMENT
GO/NO-GO SCREENING
DECISION MATRIX METHOD
Concept Selection
PRODUCT DESIGN TECHNIQUES - CONCEPTUAL DESIGN
Concept generation
FUNCTIONAL DECOMPOSITION
BRAINSTORMING
MORPHOLOGICAL ANALYSIS
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CAD
Best Modeling Practices
Part Modeling
Assembly Modeling
Drawings
MATERIAL SELECTION
ENGINEERING MODELS (form, shape, function)
SIMULATION
PRODUCT DESIGN TECHNIQUES - DETAILED DESIGN
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DFM
DFA
DFR
Preliminary Hazard Analysis
Fault Tree Analysis
Failure Modes and Effect Analysis
Risk Management (Risk engineering)
DESIGN FOR HUMAN FACTORS
DFE
Design for Disassembly
Design for recycling
Product life cycle
PRODUCT DESIGN TECHNIQUES - DETAILED DESIGN
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KNOW WHAT QFD IS AND WHAT IT IS USED FOR
Quality Function Deployment is a Quality Function Deployment is a technique developed in Japan during the technique developed in Japan during the mid-1970's for better understanding the mid-1970's for better understanding the design problem, in particular of customer design problem, in particular of customer needs.needs.
Deployment: The distribution of forces in Deployment: The distribution of forces in preparation for battle or work.preparation for battle or work.
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General Comments:
- No matter how well the design team thinks it understands a problem, it should employ the QFD technique for all mechanical design projects, because in the process the team will learn what it doesn't know about the problem.
– The customer's requirements must be translated into measurable design targets before a large amount of time and resources are invested in the design effort.
– It is important to first consider what needs to be designed and, only after that is fully understood, to worry about how the design will look and work.
Quality Function Deployment (QFD)
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1. Identify the customers: Who are they? 2. Determine the customers' requirements: What do the customers want? 3. Determine relative importance of the requirements: Who versus what 4. Generate engineering specifications: How will the customers' requirements be met? 5. Relate customers , requirements to engineering specifications: Hows measure whats? 6. Identify relationships between engineering requirements: How are the "hows" dependent
on each other?
7. Identify and evaluate the competition: How satisfied is the customer now? 8. Set engineering targets: How much is good enough?
The eight basic steps in the Quality Function Deployment technique are:
Quality Function Deployment (QFD)
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Easy to inflate
Small size defl.
Easy to maneuver
Comfortable paddle
Bounces off rocks
Self bailing
Stable
Fast
Lightweight
Affordable
Cargo space
Wei
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t
Len
gth
Wid
th
Mu
lti
cham
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Ch
amb
er v
ol
Str
eng
th m
at.
Can
adia
n C
oas
t
Customer importance
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2
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1
4
9 4
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units kg m %1 m3 N/m
85 27 27 43 1 18 18Absolute importance
relative importance
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% 39 12 12 20 0 8 8
9
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19
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2
2
2
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3
1
5
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3
2
1
5
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1
3
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4
2
1
2
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5
2
5
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A B C
COMPETITION
Quality Function Deployment (QFD)
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Functional Decomposition Technique
Functional decomposition
Morphological matrix shows alternative means of achieving given functionality
UNDERSTAND WHAT IS
FUNCTIONAL
DECOMPOSITION AND
MORPHOLOGICAL
ANALYSIS AND HOW
THEY WORK TOGETHER
TO GENERATE
CONCEPTS
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Morphological analysis is used to identify the necessary product
functionality and explore alternative means and combinations of
achieving that functionality. For each element of product function, there
may be a number of possible solutions. The morphological chart is
prepared and used to develop alternative combinations of means to
perform functions and each feasible combination represents a potential
solution.
Morphological * Analysis
* Morphology: The science of the form and structure
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CONCEPT EVALUATION TECHNIQUES
Feasibility Judgment
Technology Readiness Assessment
Go/no-go Screening
Decision Matrix Method
NumerousConcepts
Gut Feeling
State of Art
Customer Requirements
Absolute
Relative
Type of Comparison Technique Basis of Comparison
Best Concept(s)
KNOW CONCEPT SELECTION
TECHNIQUES
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PROJECT PLANNING TECHNIQUES
CPM
GANTT CHARTS
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PRELIMINARY HAZARD ANALYSIS
FAULT TREE ANALYSIS
FAILURE MODES AND EFFECT ANALYSIS
DESIGN FOR RELIABILITY TECHNIQUES (DFR)
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The output fault occurrence probabilities for AND gate is:
1AND
mF Fii
FAULT TREE ANALYSIS
F1 F2
FAND
Example:
F1 = 0.1
F2 = 0.05
FAND = 0.1 * 0.05 = 0.005INPUT EVENTS
OUTPUT EVENT
where
FAND is the probability of occurrence of the AND gate output fault event
m is the number of independent input fault events
Fi is the probability of occurrence of input fault event i, for i=1, 2, …m
AND
Be able to calculate probabilities in Fault Tree
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m
iiFFO
1R
The output fault occurrence probabilities for OR gate:
where
FOR is the probability of occurrence of the OR gate output fault event
m is the number of independent input fault events
Fi is the probability of occurrence of input fault event i, for i=1, 2, …m
Note: For small (i.e. less than 10 percent) occurrence probabilities of
input fault events of the OR gate, the above equation reduces to:
1 (1 )1
OR
mF Fii
FAULT TREE ANALYSIS
F1 F2
FOR
Example:
F1 = 0.1
F2 = 0.05
FOR = 1 – (1 - 0.1)*(1- 0.05) = 0.145INPUT EVENTS
OUTPUT EVENT
OR
Be able to calculate probabilities in Fault Tree
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RANKING PROCEDURE FOR FMEA
Risk Priority Number
RPN = R occurrence x R severity x R detection
RPN = 1 failure is highly unlikely and
unimportant
RPN = 30 it is OK
RPN = 100 failure will occur
RPN = 1000 hazardous and harmful failure
will occur
Be able to calculate RPN and discuss/justify all numbers
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The improvement potential I.P.
A T
A
N - NI.P. = × 100
N
Where:
NA is the actual number of components
NT is the theoretical minimum number of components
Rate the product on the worksheet:
If I.P. 10%, then current design is
outstanding
If 10% < I.P. 20%, then current design is
very good
If 20% < I.P. 40%, then current design is
good
If 40% < I.P. 60%, then current design is fair
If I.P. > 60%, then current design is poor
Be able to calculate I.P.
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EXAM PROBLEM
Imagine a photo of some common household object is given.
You may be asked to:
Perform DFA (13 rules) and DFM on it.
Identify failure modes and perform FMEA
Next you’ll propose a redesign to make it suitable for people with arthritis* by identifying customer needs and linking them to design specifications (QFD)
You’ll then develop two concepts complete with sketches, evaluate them and perform DFA on the winning concept and DFM on selected components..
The above is not “all inclusive”. You don’t have to memorize the 13 DFA rule but you must know how to use them in the table format to calculate scores.
* Definition of Arthritis
Arthritis is a disease that causes pain and loss of movement of the joints. The word arthritis literally means joint inflammation, and refers to more than 100 different diseases.
Description of Arthritis
Arthritis affects the movements you rely on for everyday activities. Arthritis is usually chronic. This means that it can last on and off for a lifetime.
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EXAMPLE:
A FLOUR SIFTER NEEDS TO BE REDESIGNED TO MAKE IT SUITABLE FOR
USE BY PEOPLE WITH ARTHRITIS IN HANDS
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DFA?
EXISTING FLOUR SIFTER
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FAILURE MODES AND EFFECT ANALYSIS
EXISTING FLOUR SIFTER
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CUSTOMER REQUIREMENTS FOR PEOPLE WITH ARTHRITIS
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DESIGN OF A NEW FLOUR SIFTER
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HOW TO TRANSLATE CUSTOMER REQUIREMENTS INTO ENGINEERING TARGETS?
DESIGN OF A NEW FLOUR SIFTER
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?CREATE TWO CONCEPTS: CONCEPT 1, CONCEPT 2
WHAT TECHNIQUES CAN WE USE FOR CONCEPT CREATION?
BE PREPARED TO SKETCH YOUR CONCEPTS
DESIGN OF A NEW FLOUR SIFTER
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WHAT TECHNIQUES CAN WE USE FOR CONCEPT EVALUATION?
?Decision-Matrix Form
Concepts for Comparison
Scores
Totals
Wei
gh
tsCustomer Requirements
The relative importance of requirements found using pair-wise comparison technique
Concepts to be compared
1 2
3
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DESIGN OF A NEW FLOUR SIFTER
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The winnerRelative importance of requirements
DESIGN OF A NEW FLOUR SIFTER
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We have selected our concept, is it better or worse as compared to the existing sifter?
DFM?
DFA?
DESIGN OF A NEW FLOUR SIFTER
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Performance requirements of the material in our proposed flour sifter?
Material properties associated with the above performance requirements?
Any design recommendations inspired by DFE?
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DESIGN OF A NEW FLOUR SIFTER
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PAST EXAMS
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PAST EXAMS
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GOOD LUCK ON YOUR EXAMS!GOOD LUCK ON YOUR EXAMS!