Concept Evaluation

1
Concept Evaluation

• How to choose the best concept?
• How to decide as a team?
• How to document the process?

2
Methods of Decision-Making

• External decision
• Product champion
• Intuition
• Pros and cons
• Prototype and test
• Decision matrix

3
Concept Evaluation

• Possible methods of decision making
• External decision Customers
• Product champion A member
• Intuition Gut feelings and vote

4
Concept Evaluation

• Pros cons Discussion vote of majority.
• Prototype and test
• Decision matrix Each concept is rated w/r to
  specifications and ranked.

5
Concept Evaluation in ME 492

• Two-stage methodology
• Concept screening
• Initial screening (when gt 10 concepts)
• Concept screening matrix (gt 5 concepts)
• Concept scoring
• Concept scoring matrix (lt 5 concepts)

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Initial screening

• Multi-vote technique
• Group eliminates unlikely concepts.
• Allocate 10 dots to each members
• Choose the top 10 concepts

7
Matrix Methods

• Process for using matrix methods
• 1. Identify the criteria
• 2. Choose a datum
• 3. Rate the concepts
• 4. Rank the concepts

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Concept Evaluation

• Concept screening matrix
• Evaluate concepts w/r to customer needs
• Use only the most important criteria
• Choose a reference (datum) concept
• A favorite design
• A competitive product

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Concept screening matrix

• Compare each concept with the datum concept
• Give a score of for better than datum
• Give a score of - for worse than datum
• Give a score of 0 for same as datum
• Rank concepts
• An example follows Due to lack of space only 6
  concepts are compared.

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Concept Screening Example
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Concept Evaluation

• Combine and improve concepts
• Select promising concepts.
• Reflect on the process.

12
Matrix Methods

• It is important to have a single category for
  each important criteria. For example do not
  breakdown cost into
• Cost
• Ease of manufacture / Assembly
• Material availability
• Labor
• This practice inflates some criteria
  unequally

13
Matrix Methods

• If it is preferred to break down criteria, make
  sure the importance is also divided between
  them
• Cost Importance 5
• Or
• Materials 2
• Labor 2
• Tooling 1
• This method can be used in Scoring Matrix

14
Concept Scoring Matrix

• Concept scoring matrix
• The main (primary) criteria are listed as before
• Determine a weighting factor for each criteria
• Done in QFD (as importance)
• Rating the concepts (1-5)
• 1 Much worse than reference concept
• 2 Worse than reference concept
• 3 Same as reference concept
• 4 Better than reference concept
• 5 Much better than reference concept

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Concept Scoring Matrix

• Alternate Absolute Scale Scoring
• Rating the concepts (1-5)
• 1 Useless Very inferior
• 2 Poor - inferior
• 3 Acceptable
• 4 Good or superior
• 5 Excellent or much superior

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Example

• Consider buying a TV
• Selection Criteria
• Cost
• Screen size
• Image clarity
• Warrantee
• Looks

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Example

• Brand-A
• Cost 350, size 25, 1 year, 0.28mm, Not too
  bad
• Brand-B
• Cost 175, size 19, 6 month, 0.19mm, Beautiful
• Brand-C
• Cost 430, size 27, 2 year, 0.28mm, Very ugly
• Brand-D
• Cost 275, size 21, 1 year, 0.15mm, ugly

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Conversion of Performance
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Evaluations Matrix
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Concept Evaluation

• Rate and rank concepts
• Combine and improve
• Select one concept
• Assess the effect of variation in rates and
  weights on the final results.
• Assess how much difference is really significant.
• Reflect on the results
• This is the point of no return - Everyone on
  the team must be in agreement about it.