Transcript Document

The Design Process:
Problem Formulation
Charles A. DiMarzio
GEU110
Northeastern University
September 2003
Chuck DiMarzio, Northeastern University
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The Design Process
• Remember these
phases are not absolute
• The edges are rough
• We often use multiple
loops
• Usually we don’t think
about the process at all
• It’s best taught by
examples
September 2003
Needs
Assessment
Implementation
11
Analysis
8,9,10
Abstraction
and Synthesis
6,7
Chuck DiMarzio, Northeastern University
Ch. 2
Problem
Formulation
3, 4, 5
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What is the Real Problem?
• Constraints and Boundaries (quantitative)
– Maximum size hole in aircraft for Lidar
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Qualitative Goals (“more” or “less”)
Restate Goal, Change Emphasis
Input/Output Analysis
???
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Revision Method
• Method
– Start with something that works,
– Build it,
– Refine it through evolutionary design.
• Advantages
– Working design in short time
– It just might be good enough
– It points out the approach to making it better
• Example
– Mohs Surgery
September 2003
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Duncker Diagram
System Level Problems; Environment, Transportation
Present State
Desired State
General Solutions
Functional Solutions
Specific Solutions
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Kepner-Tregoe Situation
Analysis
Timing (urgency)
Trend (growth)
Impact (consequences)
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Kepner-Tregoe Problem Analysis
What
Is?
What
Is Not?
Distinction
Cause of
Distinction
Identity
Location
Timing
Magnitude
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Kepner-Tregoe Problem Analysis
What is? What is not? Distinction?
September 2003
Chuck DiMarzio, Northeastern University
Possible
Cause?
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What is the Value of These
Methods?
• Thinking (Alone)
• Brainstorming (Together)
• Justifying (to whom?)
Think about formal vs. Informal use
of these Methods.
September 2003
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An Example
• Severe Storms Lidar Scanner to produce a
stable scan pattern from an aircraft with
roll, pitch (and heading?).
• 13” hole in airplane
• Airworthyness issues for outside structures
• Cost, speed (1/4 sec), etc.
September 2003
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Example Continued
• Proposal Brainstorming
– Stick Model for Light Beams
– 2 Mirrors, Gimbled Mirror, Flip Mirror
– Outside Structure, Wedge, 2 Wedges
• Abstraction, Synthesis, Analysis for Each
• Implementation only for 2 Wedges
– Then developed more complicated model with
calibration
September 2003
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Major Project Guidelines
• What are you proposing?
– One of a kind (eg. Bridge)
– One at a time (eg. femtosecond laser)
– Mass production (eg. Consumer product)
• Prototype (think about design and single-unit cost)
• Production line (think about cost per unit)
September 2003
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Some Major Project Issues
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Why is your design needed?
Needs
What problem are you trying to solve?
Assessment
Implementation
Ch. 2
Why is your solution best?
11
Problem
Analysis
What analysis will you do?
Formulation
8,9,10
3, 4, 5
Who can/will pay the required cost?
Abstraction
and Synthesis
What are the unintended consequences?
6,7
What are the political and social issues?
What are the environmental issues?
What expertise do you need on your team?
September 2003
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Minor Project
• Grading on
– Report (40%)
– Device (40%)
– Success (20%)
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A Word About Reports
• I give points for
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Cover Letter (If appropriate)
Abstract
Table of Contents and Figures
Technical Content (Most heavily)
References (If appropriate)
Grammar and Spelling
General Appearance
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Some Grammar Issues
• A preposition is a terrible part of speech to
end a sentence with.
• And starting with a conjunction isn’t much
better.
• Another thing. Little short phrases. Not
quite sentences. Not good. Unless you are
Jonathan Franzen.
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Some Style Issues
• Use section headings.
• Informal expressions in technical writing are
usually uncool.
• Use parallel constructions in lists.
– Never have one item in a sublist
• Active voice and first person are acceptable to me,
but not to everyone in engineering.
– “Mistakes were made.”
– You shouldn’t use the second person.
• Give figures and tables numbers, and refer to them
in the text.
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Websites as Sources
• Use the web to...
– Learn about a new field
– Find out who is working in the field
– Get pointers to the archival literature
• Do not use web pages as citations
– They are transient
– They are not refereed
– Catalog information for pricing, etc. is an exception if
you include date information, etc.
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Some Ethical Issues
• If you borrow a figure, cite the source.
• Reference anyone who contributes to your
idea.
• Paraphrasing is not the same thing as
expressing your own thoughts.
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Teams
• 1: Rishi Dhupar, Bryan
Mayor, Joe Mayotte
• 2: Matt Bouchard, Brian
Carlin, Anne Fitzpatrick
• 3: Eric Blaisdell, David
Despres, Mikio
Yanagisawa
• 4: Chuba Arah, Marco
Solia, Jonathan Palmer
• 5: Shannon Rooney,
Jenine Davignon, Kevin
Harvey
September 2003
• 6: Sean O'Blenis, Kelly
Chronley, Sammy Shaar
• 7: Graham Turner, Danny
MacDougall, Steve Jahnes
• 8: Dan Bastable, Bryan
Fors, Kyle Nowak
• 9: Jonathan Correia,
Marsel Kane, Khue
Nguyen, Steve Yu
• 10: Michael Hart, Mike
Santorella, Robert Taylor
Chuck DiMarzio, Northeastern University
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