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Product Design and Development
Final 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.
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Sample question:
Identify fits A, B, C
ec001.SLDASM
hole
shaft
Clearance fit
hole
shaft
Transition fit
hole
shaft
Interference fit
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Sample question:
Identify fits A, B, C
Line fit
Transition fit
Interference fit
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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
FAILURE MODES AND EFFECT ANALYSIS
MATERIAL SELECTION
GO/NO-GO SCREENING
BRAINSTORMING
MORPHOLOGICAL ANALYSIS
CRITICAL PATH METHOD
FAULT TREE ANALYSIS
SIMULATION
ENGINEERING MODELS
DFE
QUALITY FUNCTION DEPLOYMENT
FEA
PRODUCT LIFE CYCLE
DFM
FEASIBILITY JUDGMENT
GANTT’S CHARTS
PATENT SEARCH
DFA
PRELIMINARY HAZARD ANALYSIS
TECHNOLOGY READINESS ASSESSMENT
DECISION MATRIX METHOD
DFR
DESIGN FOR RECYCLING
FUNCTIONAL DECOMPOSITION
DESING FOR DISASSEMBLY
CUSTOMER SURVEY
CAD
RISK ENGINEERING
DESIGN FOR HUMAN FACTORS
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PRODUCT DESIGN TECHNIQUES - SPECIFICATION DESIGN
CUSTOMER SURVEY
Specification Development
QUALITY FUNCTION DEPLOYMENT
GANTT’S CHARTS
CRITICAL PATH METHOD
Planning Phase
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PRODUCT DESIGN TECHNIQUES - CONCEPTUAL DESIGN
FUNCTIONAL DECOMPOSITION
BRAINSTORMING
Concept generation
MORPHOLOGICAL ANALYSIS
FEASIBILITY JUDGMENT
TECHNOLOGY READINESS ASSESSMENT
GO/NO-GO SCREENING
Concept Selection
DECISION MATRIX METHOD
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PRODUCT DESIGN TECHNIQUES - DETAILED DESIGN
CAD
Best Modeling Practices
Part Modeling
Assembly Modeling
Drawings
MATERIAL SELECTION
ENGINEERING MODELS (form, shape, function)
SIMULATION
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PRODUCT DESIGN TECHNIQUES - DETAILED DESIGN
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
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KNOW WHAT QFD IS AND WHAT IT IS USED FOR
Quality Function Deployment is a
technique developed in Japan during the
mid-1970's for better understanding the
design problem, in particular of
customer needs.
Deployment: The distribution of forces in
preparation for battle or work.
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Quality Function Deployment (QFD)
General Comments:
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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.
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Quality Function Deployment (QFD)
The eight basic steps in the Quality Function Deployment technique are:
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?
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Quality Function Deployment (QFD)
COMPETITION
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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
relative importance
Strength mat.
Multi chamber
Chamber vol
Weight
Length
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2 1 1
4
2 5 2
3 9
3
1
2
3
2
4
2
1
219
%
2 2 2
9
1
9
1 1 2
9
9
5 3 5
3 3 3
2 2 2
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4
m
1
m3
N/m
%
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8
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43
1
18
39 12
12
20
0
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85
4 3 3
2 2 3
3 5 5
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kg
A B C
5 3 4
4
3
units
Absolute importance
Width
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Customer
importance
Canadian Coast
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Functional Decomposition Technique
Functional
decomposition
UNDERSTAND WHAT IS
FUNCTIONAL
DECOMPOSITION AND
MORPHOLOGICAL
ANALYSIS AND HOW
THEY WORK TOGETHER
TO GENERATE
CONCEPTS
Morphological matrix
shows alternative
means of achieving
given functionality
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Morphological * Analysis
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.
* Morphology: The science of the form and structure
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CONCEPT EVALUATION TECHNIQUES
Type of Comparison
Technique
Basis of Comparison
Numerous
Concepts
KNOW CONCEPT
SELECTION
TECHNIQUES
Feasibility
Judgment
Technology Readiness
Assessment
Absolute
Gut Feeling
State of Art
Go/no-go
Screening
Customer Requirements
Relative
Decision Matrix
Method
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Best Concept(s)
PROJECT PLANNING TECHNIQUES
CPM
GANTT CHARTS
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DESIGN FOR RELIABILITY TECHNIQUES (DFR)
PRELIMINARY HAZARD ANALYSIS
FAULT TREE ANALYSIS
FAILURE MODES AND EFFECT ANALYSIS
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FAULT TREE ANALYSIS
The output fault occurrence probabilities for AND gate is:
FAND
Be able to calculate
probabilities in Fault Tree
m
  Fi
i 1
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
OUTPUT EVENT
FAND
Example:
F1 = 0.1
F2 = 0.05
AND
FAND = 0.1 * 0.05 = 0.005
INPUT EVENTS
F1
F2
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FAULT TREE ANALYSIS
The output fault occurrence probabilities for OR gate:
FOR
Be able to calculate
probabilities in Fault Tree
m
 1   (1  Fi )
i 1
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
FOR
OUTPUT EVENT
Example:
F1 = 0.1
OR
F2 = 0.05
INPUT EVENTS
F1
F2
FOR = 1 – (1 - 0.1)*(1- 0.05) = 0.145
Note: For small (i.e. less than 10 percent) occurrence probabilities of
input fault events of the OR gate, the above equation reduces to:
m
FOR   Fi
i 1
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RANKING PROCEDURE FOR FMEA
Risk Priority Number
Be able to calculate RPN
and discuss/justify all
numbers
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
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The improvement potential I.P.
Be able to calculate I.P.
I.P. =
NA - NT
× 100
NA
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
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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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EXISTING FLOUR SIFTER
DFA?
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EXISTING FLOUR SIFTER
FAILURE MODES AND EFFECT ANALYSIS
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DESIGN OF A NEW FLOUR SIFTER
CUSTOMER REQUIREMENTS FOR PEOPLE WITH ARTHRITIS
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DESIGN OF A NEW FLOUR SIFTER
HOW TO TRANSLATE CUSTOMER REQUIREMENTS INTO ENGINEERING TARGETS?
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DESIGN OF A NEW FLOUR SIFTER
CREATE TWO CONCEPTS: CONCEPT 1, CONCEPT 2
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WHAT TECHNIQUES CAN WE USE FOR CONCEPT CREATION?
BE PREPARED TO SKETCH YOUR CONCEPTS
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DESIGN OF A NEW FLOUR SIFTER
WHAT TECHNIQUES CAN WE USE FOR CONCEPT EVALUATION?
?
Decision-Matrix Form
Concepts to be
compared
Concepts for Comparison
Customer
Requirements
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The relative importance
of requirements found
using pair-wise
comparison technique
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Scores
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Totals
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DESIGN OF A NEW FLOUR SIFTER
Relative importance
of requirements
Evaluation Based on Decision Matrix
The winner
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DESIGN OF A NEW FLOUR SIFTER
We have selected our concept, is it better or worse as compared to the existing sifter?
DFM?
DFA?
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DESIGN OF A NEW FLOUR SIFTER
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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PAST EXAMS
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PAST EXAMS
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GOOD LUCK ON YOUR EXAMS!
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