EML4550 - Engineering Design Methods - PowerPoint PPT Presentation

Title: EML4550 - Engineering Design Methods


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EML4550 - Engineering Design Methods

• Concept Generation
• Generating ideas and design concepts
• Concept Selection
• Settling on one or more promising ideas to pursue
  to final design
• Hyman Chapter 6 and Sec. 9.1 9.2
• Ulrich and Eppinger Chapters 5 and 6
• Dym and Little Sections 6.1 6.3

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Concept Development Diagram (Hyman Chapter 6)
Establish Target Specs
Generate Product Concepts
Identify Customer Needs
Refine Specs
Mission Statement
Action Plan
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Concept Generation

• A conceptual design is an approximate
  representation of the final product
• Sketches, 3-D renderings, back-of-the-envelope
  calculations to assess feasibility
• Concept generation is typically low-cost (5 of
  project) and somewhat time-consuming (15 of
  schedule)
• Need to explore ALL possible concepts, structured
  approach to avoid pitfalls
• Consideration of only a few options, failure to
  consider competitors concepts, involvement by
  just a few people, failure to follow through
  partial solutions, failure to see entire
  categories of solutions

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Concept Generation (contd)

• Creative part of the design process
• Least structured part of the process
• It is OK to allow some chaos during project
  inception (shake down the ideas)
• However, in order to avoid major oversights, we
  need to introduce some structure to the concept
  generation phase

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Models for the creative process

• Wallas model
• Fabun model
• CEF model
• Consolidated model

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Wallas model (1926)

• Preparation
• Clarify and define problem (recognizing the need,
  defining the problem)
• Incubation
• Formative stage, mind is relaxed and free to
  receive ideas
• Illumination
• First conscious recognition of an idea
  (Eureka!)
• Verification
• Reality check on the idea

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Fabun model (1968)

• Desire
• Equilibrium broken by appearance of a problem
• Preparation (same as Wallas)
• Manipulation
• Mind actively manipulates ideas/gathers
  information
• Incubation (same as Wallas)
• Intimation
• Realization we are on the right track
• Illumination (same as Wallas)
• Verification (same as Wallas)

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CEF (Creative Education Foundation) model (1976)

• Fact finding
• Collect all facts that may bear on the problem
• Problem finding
• Articulate problem formulation(s)
• Idea finding
• Solutions are presented
• Solution finding
• Solutions are evaluated and one is selected
• Acceptance finding
• Customer buy-off and implementation

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Consolidated model

• Exploration
• Active and concerted search for new ideas with
  possible frustrating results (need to pursue
  further)
• Incubation
• Formative stage when extended period of
  relaxation without a conscious effort to solve
  the problem
• Intimation
• Resumption of search effort with the feeling of
  making progress
• Illumination
• Breakthrough that produces a new and attractive
  idea

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Barriers to Creative Thinking

• Perceptual (inability to properly perceive
  problem, unnecessary inference, etc. Most
  frequently encountered)
• Patterns, boundaries (cant think outside the
  box), illusions, lenses (cant see the forest for
  the trees), meanings
• Cultural (imposed by society, how to think
  unconventionally)
• Environmental (anything in the surrounding that
  stifles creativity, both physical or in terms of
  personal work conditions such as overly critical
  and rigid behavior)
• Emotional (emotional baggage from personal life)
• Intellectual (not enough knowledge on the topic ?
  life-long learning to update ones knowledge)

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Removing Barriers/Techniques to Generate
Alternatives

• Lateral thinking (as opposed to vertical
  thinking)
• Generate as many ideas as possible (crazy is
  good)
• Do not go deep into any one idea
• Do not criticize or pre-judge ideas (dont
  evaluate until you conceptualize all options.
  Need will power and discipline to resist)
• Perseverance
• Invention is 95 perspiration, 5 invention
  (Edison)
• Mental push-ups
• Engage on creative design activities often
• Get involved with other projects

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Removing Barriers/Techniques to Generate
Alternatives (Contd)

• Making lists
• As an exercise, take common objects and list no
  less than 20 uses
• Get used to thinking of common objects in
  uncommon ways
• Word games
• Cryptic crossword puzzles (meaning barriers)
• Solving puzzles
• Classical puzzles, cubes, 2-D boards, etc.
  (boundary barriers)

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Concept Generation

• Practical Approaches and Examples

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Concept Generation Methodology
Clarify the problem
Search externally
Search Internally
Explore systematically
Reflect on the process and the solutions
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Clarify the problem

• Understanding (needs, specs, objectives)
• Decompose complex problems into simple
  sub-problems
• Decomposition by function
• Create boxes and function diagrams
• Create boxes and flow diagrams
• Decomposition by sequence of user actions
• Decomposition by needs
• Decomposition by field of competence
• Identify critical sub-problems and concentrate
  early efforts on them

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Search externally

• Interview lead users (customers)
• Consult experts (consultants)
• Search patents
• Databases Lexis/Nexis, Dialog, etc. (through
  Library)
• US Patent Trademark Office ( http//www.uspto.go
  v )
• Search published literature
• Databases (through Library)
• Trade journals and magazines
• Benchmark related products
• Thomas Register

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Search internally

• Ground rules
• Suspend judgment until after exercise is complete
• Generate a lot of ideas
• Accept ideas that may appear infeasible
• Use graphical and physical media (models)
• Use both group and individual sessions
• Where ideas come from
• Make analogies
• Wish and wonder
• Individual ideas (related stimuli) or random
  ideas (unrelated stimuli) presented to group
• Set quantitative goals (nobody leaves until)
• Use gallery method display a large number of
  ideas visually for discussion

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Explore systematically

• The internal and external searches should have
  generated many ideas (or solution fragments) -
  potentially hundreds if the problem is complex
  enough
• Objective is to organize these ideas so that they
  can be properly evaluated later
• Concept Classification Tree
• Concept Combination Table
• Managing the Exploration Process

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Concept Classification Tree

• Identification of independent approaches to the
  problem
• Helps clarify the choices can be used to
  delegate individual efforts
• Pruning of less promising branches
• Foster an early elimination
• Exposure of undue emphasis on certain branches
  (solutions)
• By contrast, finding branches that were
  overlooked
• Refinement of problem decomposition for a
  particular branch

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Concept Classification Tree Example
Energy Source
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Concept Combination Table

• Decompose system by functional steps, or by
  physical sub-systems (or any other decomposition
  that makes sense)
• Enumerate solution-fragments for each of the
  categories
• Make a table with these entries
• Problem solution can be arrived at by combining
  entries from the table (combination of
  solution-fragments)

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Example
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Morphological Chart
Reservoir Square Tank Rectangular
Circular Tank Tank
Support
Steel Beams Wood Table
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Concept Generation Implications to Project

• Statement that clarifies the problem and sets
  boundaries on its scope
• A record of the search for ideas (internal and
  external)
• Tables or diagrams presenting all the ideas
  generated, and concepts that were considered
• An exhaustive and well-organized set of ideas
  and/or conceptual designs