% of product cost committed
IMPORTANCE OF PROPER PROBLEM DEFINITION
100
80
60
40
20
0
Specification
Development
Conceptual
Design
Detailed
design
Time
After specifications phase, we have already committed ~40% of product cost!
1
CONCEPTUAL DESIGN PHASE
1. Specification Development / Planning Phase
Gantt charts
CPM
Customer surveys
Customer interviews
QFD
Determine need, customer and engineering requirements
Develop a project plan
2. Conceptual Design Phase
Generate and evaluate concepts
Select best solution
3. Detail Design Phase
Documentation and part specification
Prototype evaluation
4. Production Phase
Component manufacture and assembly
Plant facilities / capabilities
5. Service Phase
Installation, use , maintenance and safety
6. Product Retirement Phase
Length of use, disposal, and recycle
2
CONCEPT GENERATION
Concept - is an idea that can be represented in a rough
sketch or with notes of what might someday be a product.
3
CONCEPT GENERATION
If you generate one idea it will probably be a poor idea
if you generate twenty ideas then you might have one good idea
4
CONCEPT GENERATION
So how do we generate those concepts?
Basic philosophy for generating concepts:
Form follows function
Creativity must be controlled by engineering
judgment / expertise / experience
5
CONCEPT GENERATION AND SELECTION
SUMMARY
Feasibility judgment
Functional
Decomposition
QFD
Technology readiness
Go/no go screening
Morphological
Analysis
Decision matrix method
Concept 1
Need
Required
functionality
Concept 2
Final concept
Concept 3
…
Concept n
Ideation
Brainstorming
Patents
Reference (Books, Trade Journals)
Experts’ help
6
SOURCES FOR CONCEPT IDEAS
1. Ideation
2. Brainstorming - a group oriented technique
3. Patents - extensive patent search may be required. (Note: there are
over 5 million patents in the U.S.)
4. Reference books and trade journals - most reference books give
analytical techniques and few design ideas
(Trade journals are a good source, but generally are targeted at
specific disciplines).
5. Experts to help generate concepts - a good source of information
are manufacturers catelogues (check the Thomas Registry).
6. Functional decomposition and morphological analysis
7
IDEATION
1. Get a general idea of the design problem and
develop different ways to tackle it
Do not worry about practicality
Do not refine ideas
2. Find feasible ideas
If only some elements of an idea work, extract
them for inclusion in the next iteration
3. Pick, choose and recombine ideas
Using useful elements from all ideas
4. Refine
List three concepts and add elements you really
need in the finished product
8
BRAINSTORMING
Fundamental Principles of Brainstorming
1. Criticism is not allowed - any attempt to analyze, rejecty, or
evaluate ideas is postponed until after the brainstorming session.
2. All ideas brought forth should be picked up by the other
people - participants should seek ways of improving the ideas of
others.
3. Participants should divulge all ideas that enter their mind - the
wilder the idea, the better.
4. Provide as many ideas as possible within a relatively short
time - the greater the number of ideas, the more likelihood of useful
results.
9
BRAINSTORMING
Brainstorming is an organized approach for producing creative ideas by letting the mind
think without interruption. Brainstorming can be done either individually or in a group; in
group brainstorming sessions, the participants are encouraged, and often expected, to
share their ideas with one another as soon as they are generated. The key to
brainstorming is not to interrupt the thought process. As ideas come to the mind, they
are captured and stimulate the development of better ideas.
An essential element of brainstorming is putting criticism 'on hold'. Instead of
immediately stating what might be wrong with an idea, the participants focus on
extending or adding to it, reserving criticism for a later 'critical stage' of the process.
By suspending judgment, you create a supportive atmosphere where participants
feel free to generate unusual ideas.
10
BRAINSTORMING
Procedure for a typical brainstorming session
A meeting room is equipped with a flipchart, blackboard, or overhead projector placed in a
prominent location.
Between six and twenty people with an interest in the subject (although not necessarily experts)
are invited to participate.
Write on the flipchart (or blackboard) a statement of the subject or problem that will be discussed.
This is often presented as a question.
Choose one person to write down the ideas generated. Ideas should be written concisely but
without paraphrasing. The recorder should state the idea in the words she has written to ensure
that it expresses the meaning intended by the originator.
Choose one person to facilitate the process. This involves encouraging participation by
everyone and maintaining a criticism free, uninhibited atmosphere. Encourage even wild and
seemingly ridiculous ideas.
After 5 to 20 minutes the facilitator ends the session
Review the list from top to bottom to ensure everyone understands the ideas. Eliminate from the
list any duplications. Remove any obviously ridiculous suggestions.
11
PATENTS
In the 1920s, engineers at Sperry Gyroscope Company developed a
clever design for a bearing that would hold the end of the gyro shaft in
position with great accuracy both axially and laterally, would support
the gyro, and would have low friction.
– It was patented and put into service with great success.
– However, in 1965 the same basic design was discovered in a
notebook belonging to Leonardo da Vinci dating from about 1500.
A low friction bearing from da Vinci's notebook.
[Ullman 1992]
12
SOURCES FOR CONCEPT IDEAS
REFERENCE BOOKS AND TRADE JOURNALS
http://www.machinedesign.com/
http://www. sae.org/
13
SOURCES FOR CONCEPT IDEAS – EXPERT HELP
14
FUNCTIONAL DECOMPOSITION TECHNIQUE
Step 1:
Find the overall function that needs to be accomplished.
Goal is to generate a single statement of the overall function based on the
customer requirements. All design problems have one or two "most important"
functions. These must be stated in a single concise sentence.
Example: portable kayak
Design a kayak that can be folded into a package small enough to fit in a
trunk of a car
Step 2:
Decompose the function into subfunctions (perform functional decomposition). Goal is to refine
the overall function statement as much as possible.
Guidelines:
1.
Document what not how.
2.
Use standard methods and notations whenever possible for describing subfunctions.
3.
Consider the logical relationships between the functions to determine their sequence.
4.
Match inputs and outputs in the functional decomposition.
5.
Break the main function down as finely as possible using a block diagram.
15
FUNCTIONAL DECOMPOSITION TECHNIQUE
unpack
Use
unpacked
pack
Foldable kayak
Allows reduction in size when
transported and stored
Customer
requirements
Product functions
satisfying customer
requirements
16
FUNCTIONAL DECOMPOSITION TECHNIQUE
Use
unpacked
unpack
pack
First level
decomposition
unpack
Second level
decomposition
Unfold
skeleton
Pump up
Assemble form smaller
components
Pump up
Third level
decomposition
...
...
...
Decomposing top level function into subfunctions
17
FUNCTIONAL DECOMPOSITION TECHNIQUE
AND MORPHOLOGICAL ANALYSIS*
Functional decomposition is used to identify the necessary product
functionality
Morphological analysis is used to 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
18
DEVELOPING CONCEPTS FOR EACH FUNCTION
Goal is to generate as many concepts as possible for each of the
functions identified in the Functional Decomposition process.
If there is a function for which only one conceptual idea exists,
then this function needs to be reexamined because there are very
few functions that can be fulfilled by only one concept).
19
DEVELOPING CONCEPTS FOR EACH FUNCTION
Steps:
List product functions (functional decomposition)
List the possible 'means' for each function (morphological analysis)
Chart functions and means and explore combinations
unpack
Unfold
skeleton
Pump up
Assemble form smaller
components
20
Functional decomposition of a wood splitter – in class exercise
21
COMBINING CONCEPTS INTO SINGLE CONCEPTUAL DESIGN
hold on ice
secure
Concept 1
Concept 2
Concept 3
Concept 4
Concept 1
Concept 2
Concept 3
Concept 4
Function
Design
concept
Goal is to select one concept for each function and combine
those selected into a single complete conceptual design.
Abstract concepts must now take some form, most often the form
of sketches and comments.
22
Functional decomposition
Morphological analysis
23
Functional decomposition
Morphological analysis
24
SKETCHES AND COMMENTS
Terminal cover assembly
25
SKETCHES AND COMMENTS
Assistive writing device.
– Rough sketches made in the design notebook provide a clear record of the development of
the concept and the product.
26
SKETCHES AND COMMENTS
Initial sketches and final design for a reusable syringe.
27
SOME THOUGHTS ON CREATIVITY
1. Develop a confident attitude.
[Buhl 1968]
28
SOME THOUGHTS ON CREATIVITY
2. Unlock your imagination.
[Buhl 1968]
29
SOME THOUGHTS ON CREATIVITY
[Buhl 1968]
3. Be persistant.
"Invention is 95% perspiration and 5%
inspiration"
T. Edison
30
SOME THOUGHTS ON CREATIVITY
4. Develop an open mind.
[Buhl 1968]
31
SOME THOUGHTS ON CREATIVITY
[Buhl 1968]
5. Suspend your judgement.
32
SOME THOUGHTS ON CREATIVITY
[Buhl 1968]
6. Set problem boundaries.
33
TECHNIQUES FOR EVALUATING CONCEPTUAL DESIGN
Type of Comparison
Technique
Basis of Comparison
Numerous Concepts
Feasibility
Judgment
Gut Feeling
Technology
Absolute
Readiness Assessment
State of Art
Go/no-go
Screening
Customer Requirements
Relative
Decision Matrix
Method
BEST CONCEPT
34
EVALUATION BASED ON FEASIBILITY* JUDGMENT
What we think about it?
Understanding + Experience
* Feasibility: The quality of being doable
35
EVALUATION BASED ON TECHNOLOGY READINESS ASSESSMENT
Objective - is to determine the readiness of the technologies that may be used in
the design concept. Immature technology will lead to a poor-quality product or
cancellation of a project due to cost overruns.
Time-Line for Technology Readiness
Technology
Development Time
Powered human flight
403
(1500 – 1903)
Photographic cameras
112
(1727 – 1839)
Radio
35
(1867 – 1902)
Television
12
(1922 – 1934)
Radar
15
(1925 – 1940)
Xerography
17
(1938 – 1955)
Atomic bomb
6
(1939 – 1945)
Transistor
5
(1948 – 1953)
Digital camera
30
1965 - 2004
High temperature super conductor ?
1987 - ?
Electric car
1900 - ?
…..
36
EVALUATION BASED ON TECHNOLOGY READINESS ASSESSMENT
Six measures to determine if a technology is mature:
1. Can the technology be manufactured with known processes?
2. Are the critical parameters that control the function identified ?
3. Are the safe operating parameters known ?
4. Have the failure modes been identified ?
5. Does hardware exist that demonstrates positive answers to the
above four questions ?
6. Is the technology controllable throughout the product's life cycle ?
37
EVALUATION BASED ON TECHNOLOGY READINESS ASSESSMENT
Displacement on Demand has been in works for the last 25 years…..
finally:
GM announces that the 2005 model year GMC Envoy XL, Envoy XUV and Chevrolet trailblazer EXT
will be the first vehicles to showcase its innovative Displacement on Demand fuel-saving technology,
which enhances fuel economy without compromising performance or the ability to carry heavy loads.
Displacement on Demand is to be a standard feature in the vehicles' optional Vortec 5300 V-8 engine.
The technology, which boosts the Vortec engine's fuel efficiency by 8 percent, is also to be introduced
in other GM engines in the 2006 model year.
38
EVALUATION BASED ON TECHNOLOGY READINESS ASSESSMENT
2000
2010
Hybrid car
39
EVALUATION BASED ON TECHNOLOGY READINESS ASSESSMENT
http://www.veva.bc.ca/enfield/enfield1.jpg
http://www.dieselstation.com/pics/2011-Holden-Volt-car-pics.jpg
2004
2010
Electric car
40
EVALUATION BASED ON TECHNOLOGY READINESS ASSESSMENT
Film camera
Digital camera
41
EVALUATION BASED ON TECHNOLOGY READINESS ASSESSMENT
Incandescent
Luminescent
LED
42