Concept Selection. Teaching materials to accompany: Product Design and
Development. Chapter 7. Karl T. Ulrich and Steven D. Eppinger. 2nd Edition,
Irwin ...
Concept Selection
Teaching materials to accompany: Product Design and Development Chapter 7 Karl T. Ulrich and Steven D. Eppinger 2nd Edition, Irwin McGraw-Hill, 2000.
Product Design and Development Karl T. Ulrich and Steven D. Eppinger 2nd edition, Irwin McGraw-Hill, 2000. Chapter Table of Contents 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.
Introduction Development Processes and Organizations Product Planning Identifying Customer Needs Product Specifications Concept Generation Concept Selection Concept Testing Product Architecture Industrial Design Design for Manufacturing Prototyping Product Development Economics Managing Projects
Concept Development Process Mission Statement
Identify Customer Needs
Establish Target Specifications
Generate Product Concepts
Select Product Concept(s)
Test Product Concept(s)
Perform Economic Analysis Benchmark Competitive Products Build and Test Models and Prototypes
Set Final Specifications
Plan Downstream Development
Development Plan
Concept Development Funnel
concept generation concept screening concept scoring concept testing
Concept Selection Process • Prepare the Matrix – Criteria – Reference Concept – Weightings
• Rate Concepts – Scale (+ – 0) or (1–5) – 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
FOCUS – Select Concept Effectiveness and feasibility are key evaluative criteria for screening possible solutions Effectiveness: How directly will it address the concern behind the customer requirement? How much effect will the idea likely have if implemented well? Feasibility Implementation issues: Ease, time, cost, available resources, training required, changes in behavior required, compatibility with existing capabilities or competencies, … Sr. Design, Dr. Kremer,1
FOCUS – Select Concept Prior to rating ideas, teams should discuss and define what effectiveness and feasibility mean in the context of their potential solutions Recommended visual evaluation system
Strong candidates for inclusion in final solution
Review for strong points to include
Ignore
Sr. Design, Dr. Kremer,2
FOCUS – Select Concept Completed matrices are aids to decision making, not substitutes for it Solutions to be implemented are nearly always combinations of ideas Revise and refine solution components as needed until you have consensus on the complete solution • Do final ratings match what your experience tells you is true? • Is anything missing? Sr. Design, Dr. Kremer,3
Example: Concept Screening CONCEPT VARIANTS SELECTION CRITERIA Ease of Handling Ease of Use Number Readability Dose Metering Load Handling Manufacturing Ease Portability PLUSES SAMES MINUSES NET RANK CONTINUE?
A
B
C
D
E
F
G
REF.
0 0 0 + 0 + + 3 4 0 3 1 Yes
0 – 0 + 0 – + 2 3 2 0 3 Yes
– – + + 0 – – 2 1 4 –2 7 No
0 0 0 + 0 0 – 1 5 1 0 5 No
0 0 + + 0 0 0 2 5 0 2 2 Yes
– + 0 0 + – – 2 2 3 –1 6 No
– 0 + + 0 0 – 2 3 2 0 4 Yes
0 0 0 0 0 0 0
Example: Concept Scoring Concepts A (reference) Master Cylinder
DF
E
Lever Stop
Swash Ring
Weight
Rating
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
Ease of Handling
Total Score Rank Continue?
Rating
Dial Screw+
Weighted Score
Selection Criteria
Weighted Score
G+
Rating
Weighted Score
Rating
Weighted Score
2.75
3.45
3.10
3.05
4
1
2
3
No
Develop
No
No
Remember… The goal of concept selection is not to • Select the best concept. The goal of concept selection is to • Develop the best concept. So remember to combine and refine the concepts to develop better ones!
Caveats • Beware of the best "average" product. • Perform concept selection for each different customer 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 other concepts.
