Engineering 22
Engineering
and the
Design Process
Bruce Mayer, PE
Licensed Electrical & Mechanical Engineer
[email protected]
Engineering-22: Engineering Design Graphics
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Bruce Mayer, PE
[email protected] • ENGR-22_Lec-01_Engineering_Design.ppt
Engineering - Definitions

Comes from the Latin word
“ingenerare", “to create”
•
Derivatives - ingenious, engineer
Dictionary –

•
Long  The ART or SCIENCE of Making
PRACTICAL APPLICATION of the
Knowledge of PURE SCIENCES (e.g.,
physics, chemistry) in the Construction of
USEFUL physical objects
Engineering-22: Engineering Design Graphics
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Bruce Mayer, PE
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Engineering Def. cont.
• Short = The Application of SCIENTIFIC
PRINCIPLES to PRACTICAL ENDS
 US Engineer’s Council
• The Creative Application Of Scientific
Principles To
– Design or Develop
– Construct or Operate
– Predict Behavior
• Of Structures, Machines, Apparatuses, Or
Manufacturing Processes
• Considering Function, Economics, & Safety
Engineering-22: Engineering Design Graphics
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Bruce Mayer, PE
[email protected] • ENGR-22_Lec-01_Engineering_Design.ppt
Science vs. Engineering
 Science → INVESTIGATION
• Scientists Conduct Experiments, And
Construct Models (Theories) To Better
Understand The Operation And Function
Of The Physical World
 Engineering →
PRACTICAL
PROBLEM SOLVING
• c.f. Previous Definitions
Engineering-22: Engineering Design Graphics
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Bruce Mayer, PE
[email protected] • ENGR-22_Lec-01_Engineering_Design.ppt
Engineering vs. Science
 Engineering is Closely Related to
Science & Math, but it is NOT the SAME
Scientists seek to
UNDERSTAND WHAT IS,
while Engineers seek to
CREATE THAT WHICH
NEVER WAS
- Theodore von Kármán, CalTech
Professor, and the Father of Modern
AeroSpace Engineering
Engineering-22: Engineering Design Graphics
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Bruce Mayer, PE
[email protected] • ENGR-22_Lec-01_Engineering_Design.ppt
Application of Science → Design
 Engineering Design Definitions
• Long = The Process Of Bringing Together
Engineering Principles, Material
Resources, And Creativity To Produce A
New Solution To A Well Defined Problem
• Short = Process of Solving a Practical
Problem
 Can Be Roughly Divided into Six Design
Steps (DSs)
Engineering-22: Engineering Design Graphics
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Bruce Mayer, PE
[email protected] • ENGR-22_Lec-01_Engineering_Design.ppt
DS1 – Problem Identification
 What Problem Requires Solution?
• A Clear Definition of the Problem is a
CRITICAL STEP in the Design Process
– What Are the User’s (Customer’s) Needs?
– Design Criteria
 What Limitations Or Conditions Will Restrict The Design?
 Development-Cost/Time vs. Performance Trade-offs
 Set Priorities → NEED-to-have vs. NICE-to-have
• Write a Formal Problem Statement
– Careful Accounting of All FUNCTIONAL
REQUIREMENTS
Engineering-22: Engineering Design Graphics
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Bruce Mayer, PE
[email protected] • ENGR-22_Lec-01_Engineering_Design.ppt
DS2 – Ideas and Concepts
 Brainstorming
• “Stream of Conscience” Listing Of Potential
Solutions
– NO Wrong Answers → Wild Speculation
Encouraged
• CONCEPT SKETCHES
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Bruce Mayer, PE
[email protected] • ENGR-22_Lec-01_Engineering_Design.ppt
DS3 – Preliminary Design
 Evaluate Brainstorm List
• Feasibility Analysis
– List PROs & CONs for Each Idea or Concept
 Quantify if possible
• Combine/Group Ideas to Form New
Concepts
• Develop Simple Math
or Computer Models
• REFINE SKETCHES
Engineering-22: Engineering Design Graphics
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Bruce Mayer, PE
[email protected] • ENGR-22_Lec-01_Engineering_Design.ppt
DS4 – Refine Concepts
 Further Quantification of the Merits of
Preliminary Design Candidates
• More Sophisticated Computer/Math
Modeling
• Extensive Search for “Fatal Flaws”
• Detailed “Architectural level” Drawing(s)
– Physical-Envelopes For Main Functional-Blocks
Defined And Fit-Together
• Subscale Testing
• Rapid Prototyping
Engineering-22: Engineering Design Graphics
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Bruce Mayer, PE
[email protected] • ENGR-22_Lec-01_Engineering_Design.ppt
“System Architectural” Drawing
 “Architecture” of a
Machine Tool Used
to Fabricate
Semiconductor
Integrated Circuits;
i.e. Computer chips
 Circa 1992
Engineering-22: Engineering Design Graphics
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Bruce Mayer, PE
[email protected] • ENGR-22_Lec-01_Engineering_Design.ppt
DS-5 Initial Selection
 Based on Math-Modeling and Subscale
Testing; Select a Final Design Concept
 Apply Engineering And Scientific
Principles To Evaluate The Design
• Stress, Thermal, Fluid, Electrical, Power,
Safety, Materials,
Manufacturability
• Detailed Product
COST Estimate
• 1st-Cut SCHEDULE
Engineering-22: Engineering Design Graphics
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Bruce Mayer, PE
[email protected] • ENGR-22_Lec-01_Engineering_Design.ppt
DS-6 Implementation
 GRAPHICAL Documentation
• Design Drawings (Patent Application)
• Working Drawings (Fabrication & Assembly)
• Technical Illustrations (Instruction Manual)





Build Full-Scale Prototype
Test, Test, Test
Product Marketing
Production Planning
Life-Cycle Planning (service, spares.etc.)
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Bruce Mayer, PE
[email protected] • ENGR-22_Lec-01_Engineering_Design.ppt
FlowChart

Three MAJOR Phases
1. Concept Design:
search for adaptable
solution principles
2. Initial Selection: find
suitable hardware
within technical and
economic constraints
3. Detail Design: finalize
the form, dimensions,
materials etc. of
individual components.
Engineering-22: Engineering Design Graphics
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http://www.mech.uwa.edu.au/DANotes/design/whereto/whereto.html
Bruce Mayer, PE
[email protected] • ENGR-22_Lec-01_Engineering_Design.ppt
Universal New Product Development Curve
10,000
Number of Ideas
3000 Raw Ideas (Unwritten)
Only 1 out of 125
Patents-GRANTED
yield commercially
viable products
1000
300 Ideas Submitted
100
125 Small Projects
9 Early Stage Devel.
10
4 Major Devel.
1.7 Launches
1
1
2
3
4
5
6
Stage of NPD Process
7
60% Success Rate
from Launch (1/1.7) Think “New Coke”
Ref = G. Stevens, J. Burley, James; R. Divine, “Creativity plus business discipline
equals higher profits faster from new product development”, Journal of Product
Innovation Management, vol. 16, no. 5, pp. 455-468 , 1999
Engineering-22: Engineering Design Graphics
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Bruce Mayer, PE
[email protected] • ENGR-22_Lec-01_Engineering_Design.ppt
Done for 1st Meeting
Please see me if
you would like to
ADD
Engineering-22: Engineering Design Graphics
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Bruce Mayer, PE
[email protected] • ENGR-22_Lec-01_Engineering_Design.ppt
Appendix
Details
of
Design Process
Ref = http://www.bergen.org/technology/despro.html
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Bruce Mayer, PE
[email protected] • ENGR-22_Lec-01_Engineering_Design.ppt
THE PROBLEM
 The process of designing begins when there is a need.
 Wherever there are people there are problems needing
solutions. In some cases the designer may have to invent
a product. An example might be a game for blind persons.
 At other times the designer may change an existing
design. (If the handle of a pot becomes too hot to touch, it
must be redesigned.)
 Designers also improve existing products. They make the
product work even better. Could the chair in the waiting
room of a bus or train station be altered so that waiting
seems shorter?
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Bruce Mayer, PE
[email protected] • ENGR-22_Lec-01_Engineering_Design.ppt
THE DESIGN BRIEF
 A design brief should describe simply and clearly what is
to be designed. The design brief cannot be vague. Some
examples of problems and design briefs are listed below:
• PROBLEM: Blind people cannot play many of the indoor
games available to sighted people.
• DESIGN BRIEF: Design a game of dominoes that can be
played by blind people.
• PROBLEM: The handle of a pot becomes too hot to hold
when the pot is heated.
• DESIGN BRIEF: Design a handle that remains cool when
the pot is heated.
• PROBLEM: Waiting time in a bus or train station seems too
long. There is nothing to do.
• DESIGN BRIEF: Modify the seats so that a small television
can be attached.
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Bruce Mayer, PE
[email protected] • ENGR-22_Lec-01_Engineering_Design.ppt
INVESTIGATION
 Writing a clearly stated design brief is just one step. Now
you must write down all the information you think you may
need. Some think to consider are the following:
• FUNCTION: A functional object must solve the problem described
in the design brief. The basic question to ask is : "What, exactly, is
the use of the article?"
• APPEARANCE: How will the object look? The shape, color, and
texture should make the object attractive.
• MATERIALS: What materials are available to you? You should
think about the cost of these materials. Are they affordable? Do
they have the right physical properties, such as strength, rigidity,
color, and durability?
• CONSTRUCTION: Will it be hard to make? Consider what
methods you will need to cut, shape, form, join, and finish the
material.
• SAFETY: The object you design must be safe to use. It should not
cause accidents.
Engineering-22: Engineering Design Graphics
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Bruce Mayer, PE
[email protected] • ENGR-22_Lec-01_Engineering_Design.ppt
DEVELOPING ALTERNATIVES
 You should produce a number of solutions. It is very
important that you write or draw every idea on paper as it
occurs to you. This will help you remember and describe
them more clearly. It is also easier to discuss them with
other people if you have a drawing.
 These first sketches do not have to be very detailed or
accurate. They should be made quickly. The important
thing is to record all your ideas. Do not be critical. Try to
think of lots of ideas, even some wild ones. The more
ideas you have, the more likely you are to end up with a
good solution.
Engineering-22: Engineering Design Graphics
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Bruce Mayer, PE
[email protected] • ENGR-22_Lec-01_Engineering_Design.ppt
CHOOSING A SOLUTION
 You may find that you like several of the solutions.
Eventually, you must choose one. Usually, careful
comparison with the original design brief will help you to
select the best.
 You must also consider:
•
•
•
•
Your own skills.
The materials available.
Time needed to build each solution.
Cost of each solution.
 Deciding among the several possible solutions is not
always easy. Then it helps to summarize the design
requirements and solutions and put the summary in a
chart. Which would you choose? In cases like this, let
it be the one you like best.
Engineering-22: Engineering Design Graphics
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Bruce Mayer, PE
[email protected] • ENGR-22_Lec-01_Engineering_Design.ppt
DETAILED DRAWING
 In the next step, make a detailed drawing of the chosen
solution. This drawing must include all of the information
needed to make your product. It should include the
following:
•
•
•
•
•
The overall dimensions
Detailed dimensions
The material to be used
How it will be made
What finish will be required
 Now you can choose what to do next. You can make a
model and later a prototype, or, you can go directly to
making a prototype.
Engineering-22: Engineering Design Graphics
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Bruce Mayer, PE
[email protected] • ENGR-22_Lec-01_Engineering_Design.ppt
MODELS AND PROTOTYPES
 A model is a full-size or small-scale simulation of an
object. Architects, engineers, and most designers use
models.
 Models are one more step in communicating an idea. It is
far easier to understand an idea when seen in threedimensional form. A scale model is used when designing
objects that are very large.
 A prototype is the first working version of the designer's
solution. It is generally full-size and often handmade. For
a simple object such as a pencil holder, the designer
probably would not make a model. He or she may go
directly to a prototype.
Engineering-22: Engineering Design Graphics
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Bruce Mayer, PE
[email protected] • ENGR-22_Lec-01_Engineering_Design.ppt
TESTING AND EVALUATING
 Testing and evaluating answers three basic questions:
• Does it work?
• Does it meet the design brief?
• Will modifications improve the solution?
 The question "does it work?" is basic to good design. It
has to be answered. This same question would be asked
by an engineer designing a bridge, by the designer of a
subway car, or by an architect planning a new school. If
you were to make a mistake in the final design of the
pencil holder what would happen? The result might simply
be unattractive. At worst, the holder would not work well.
Not so if a designer makes mistakes in a car's seat belt
design. Someone's life may be in danger!
Engineering-22: Engineering Design Graphics
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Bruce Mayer, PE
[email protected] • ENGR-22_Lec-01_Engineering_Design.ppt
MANUFACTURING
 The company is satisfied with the design. It knows that it is
marketable (will sell). It must decide how many to make.
Products may be mass-produced in low volume or high
volume. Specialized medical equipment is produced in
hundreds. Other products, for example nuts and bolts, are
produced in large volume. Millions may be made.
 The task of making the product is divided into jobs. Each
worker trains to do one job. As workers complete their special
jobs, the product takes shape. Mass production saves time.
Since workers train to do a particular job, each becomes skilled
in that job. Also, automatic equipment does such things as:
• Cut and shape materials
• Weld parts together
• Spray on final finishes
Engineering-22: Engineering Design Graphics
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Bruce Mayer, PE
[email protected] • ENGR-22_Lec-01_Engineering_Design.ppt