The Design Process: Problem Formulation

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The Design Process Problem Formulation

• Charles A. DiMarzio
• GEU110
• 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 dont think about the process at all
• Its best taught by examples

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What is the Real Problem?

• Constraints and Boundaries (quantitative)
• Maximum size hole in aircraft for Lidar
• 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

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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?
Cause of Distinction
Distinction
Identity
Location
Timing
Magnitude
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Kepner-Tregoe Problem Analysis
What is?
What is not?
Distinction?
Possible Cause?
Coming Later K-T Decision Analysis
(Quantitative)
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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.
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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.

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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

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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)

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Some Major Project Issues

• Why is your design needed?
• What problem are you trying to solve?
• Why is your solution best?
• What analysis will you do?
• Who can/will pay the required cost?
• What are the unintended consequences?
• What are the political and social issues?
• What are the environmental issues?
• What expertise do you need on your team?

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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
• 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 isnt 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 shouldnt 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

• 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