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Concept Selection

Teaching materials to accompany:Product Design and Development

Chapter 7

Karl T. Ulrich and Steven D. Eppinger2nd Edition, Irwin McGraw-Hill, 2000.

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Product Design and DevelopmentKarl T. Ulrich and Steven D. Eppinger

2nd edition, Irwin McGraw-Hill, 2000.

Chapter Table of Contents1. Introduction

2. Development Processes and Organizations3. Product Planning

4. Identifying Customer Needs

5. Product Specifications

6. Concept Generation

7. Concept Selection

8. Concept Testing

9. Product Architecture10. Industrial Design

11. Design for Manufacturing

12. Prototyping

13. Product Development Economics

14. Managing Projects

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Concept Development Process

Perform Economic Analysis

Benchmark Competitive Products

Build and Test Models and Prototypes

Identify

CustomerNeeds

Establish

TargetSpecifications

Generate

ProductConcepts

Select

ProductConcept(s)

Set

FinalSpecifications

Plan

DownstreamDevelopment

Mission

Statement

Development

PlanTest

ProductConcept(s)

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Concept Selection Example:

Reusable Syringe

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Concept Development Funnel

concept generation

concept screening

concept scoring

concept testing

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Concept Selection Process Prepare the Matrix

Criteria Reference Concept Weightings

Rate Concepts Scale (+ 0) or (15) Compare to Reference Concept or Values

Rank Concepts Sum Weighted Scores Combine and Improve

Remove Bad Features

Combine Good Qualities Select Best Concept

May Be More than One Beware of Average Concepts

Reflect on the Process Continuous Improvement

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Example: Concept ScreeningCONCEPT VARIANTS

SELECTION

CRITERIAA B C D E F G REF.

Ease of Handling 0 0 0 0 0Ease of Use 0 0 0 + 0 0Number Readability 0 0 + 0 + 0 + 0Dose Metering + + + + + 0 + 0

Load Handling 0 0 0 0 0 + 0 0Manufacturing Ease + 0 0 0 0Portability + + 0 0

PLUSES 3 2 2 1 2 2 2

SAMES 4 3 1 5 5 2 3

MINUSES 0 2 4 1 0 3 2

NET 3 0 2 0 2 1 0

RANK 1 3 7 5 2 6 4

CONTINUE? Yes Yes No No Yes No Yes

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Example: Concept ScoringConcepts

A DF E G+

Master Cylinder Lever Stop Swash Ring Dial Screw+

Selection Criteria Weight Rating WeightedScore Rating WeightedScore Rating WeightedScore Rating WeightedScore

Ease of Handling 5% 3 0.15 3 0.15 4 0.2 4 0.2

Ease of Use 15% 3 0.45 4 0.6 4 0.6 3 0.45

Readability of Settings 10% 2 0.2 3 0.3 5 0.5 5 0.5

Dose Metering Accuracy 25% 3 0.75 3 0.75 2 0.5 3 0.75

Durability 15% 2 0.3 5 0.75 4 0.6 3 0.45

Ease of Manufacture 20% 3 0.6 3 0.6 2 0.4 2 0.4

Portability 10% 3 0.3 3 0.3 3 0.3 3 0.3

Total Score

Rank

Continue? No Develop No No

(reference)

2.75

4

3.45

1

3.10

2

3.05

3

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Concept Selection Exercise:Mechanical Pencils

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Mechanical Pencils:Customer Needs

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Mechanical Pencils:Concept Selection Matrix

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Retail Prices of Five Pencils

Classic $2.75 Quick Click $2.58

Twist Erase $2.08 Zz $0.90

Bic $0.33

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Caveats

Beware of the best "average" product.

Perform concept selection for each differentcustomer group and compare results.

Check sensitivity of selection to the

importance weightings and ratings. May want to use all of detailed requirements in

final stages of selection.

Note features which can be applied to otherconcepts.