Lecture 05 Concept Selection Chapter 7

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Lecture 05 Concept SelectionChapter 7

• Show LF cards to Drew at end of class
• Last safety certification R 9/13 115
• Visit LF and sign-up for machining classes
• T 9/18 or R 9/20 600-1000
• Hardcopy of SW parts 1 and 2 due today
• Hardcopy of SW part 3 due W 9/16
• Read Chapter 6 and 7 - Quiz 3 on F 9/14
• Project 1 deliverables
• Critical review due today
• 3 minute pitch in-class F 9/14
• 8 minute presentation in-class W 9/19
• Final proposal due F 9/21

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Project Deliverables

• 3 minute pitch to class on F 9/14
• One speaker, one or two slides
• Design slide
• Description of how concept meets customer needs
• Image (sketch, rendering) of product
• Production cost per unit
• Marketing slide
• Describe market and estimated volume
• Marketing strategy (unique selling position)
• Selling price
• Not graded
• Send by Email or bring on CD, USB is not
  acceptable

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Project Deliverables (continued)

• 8 minute project presentation on W 9/19
• Two speakers maximum (must be different than
  pitch)
• Five slides maximum
• Prototype if available
• Graded
• See Lecture 06 for effective presentations
• Send by Email or bring on CD, USB is not
  acceptable
• Final proposal using outline in project packet
• Due F 9/21
• Submit as PDF to hjs1_at_psu.edu
• Graded

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How to Select from Multiple Design Choices

• REMEMBER
• Design is a Decision Making Process
• Decision Matrix
• Unweighted for concept screening
• To reduce many choices to just a few
• Weighted criteria for concept scoring
• More detailed comparison for selection of one
  best concept

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Decision Matrix for Concept Screening
Design Alternatives
Bumper_A Bumper_B Bumper_C Bumper_D
Cost Weight Appearance Safety Reliability
SCORE (either numerical, or /- to a reference)
Design Criteria
Numerical Scoring 0 far below average 3
average 5 far above average
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Concept Generation and Screening

• Review list of concepts
• Add any new ideas from External Search
• Construct Concept Screening Matrix
• Score Concepts ( better, 0 same, - worse)
• Rate Concepts

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Concept ScreeningUnweighted Decision Matrix
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Screening Concepts

• Combine and improve
• Narrow choices if appropriate
• Iterate if necessary
• Select one or more concepts
• Reflect on results and the process
• Down-select to two or three concepts for further
  development
• What reference design will you use?
• What criteria will you use?

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Refine Concepts

• Prior to doing your final down-select, refine
  your concepts
• Create product specifications for the criteria in
  your matrix
• Use a weighted scoring matrix for final concept
  selection
• What weighting factors?
• Try to judge from needs of customers

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Concept ScoringWeighted Decision Matrix
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Weighting Factors

• Formal methods exist to determine weighting
  factors
• Relative importance rankings of needs can guide
  assignment of weighting factors
• Objective Tree arranged so that all levels in
  tree sum to 1
• Analytical Hierarchy Process a more formal
  mathematical process
• Reference Ch. 6 of Fundamentals of Engineering
  Design, by B. Hyman

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Common Pitfalls

• Explore the effects of different weighting
  factors on rankings (sensitivity analysis)
• Assumes that product characteristics vary
  independently
• Subjective criteria may be better judged by
  customers
• Does not typically include cost

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For Next Class

• Show LF cards to Drew
• SW part 1 and 2 due today
• SW part 3 due W 9/19
• Read Chapter 6 and 7 - Quiz 3 on F 9/14
• Project 1 deliverables
• 3 minute pitch in-class F 9/14
• 8 minute presentation in-class W 9/19
• Final proposal due F 9/21