Etm551 lecture06
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This document provides information on concept selection methods for product design. It discusses performing concept screening and scoring to evaluate concepts against criteria. Concept screening uses a coarse comparison system to rate concepts against a reference and narrow options. Concept scoring uses a weighted selection matrix with finer ratings to comprehensively score and rank concepts. Both methods follow a six-step process to prepare ratings, evaluate concepts, improve options, make selections, and reflect on the process.
Etm551 lecture06
- 1. ETM 551 Concept Selection 1 Product Design & Development Concept Selection
- 2. ETM 551 Concept Selection 2 Concept Development Process Perform Economic Analysis Benchmark Competitive Products Build and Test Models and Prototypes Identify Customer Needs Establish Target Specifications Generate Product Concepts Select Product Concept(s) Set Final Specifications Plan Downstream Development Mission Statement Test Product Concept(s) Development Plan
- 3. ETM 551 Concept Selection 3 Concept Selection Example: Reusable Syringe • Ease of handling • Ease of use • Readibility of dose settings • Dose metering accuracy • Durability • Ease of manufacture • Portability
- 4. ETM 551 Concept Selection 4 Concept selection • How can the team choose the best concept, given that the designs are still quite abstract? • How can a decision be made that is embraced by the whole team? • How can desirable attributes of otherwise weak concepts be identified and used? • How can the decision-making process be documented?
- 5. ETM 551 Concept Selection 5 Choosing a concept All teams use some method for choosing a concept • External decisions: – Concepts are turned over to the customer, client, or some other external entity for selection. • Product Champion: – An influential member of the product development team chooses a concept based on personal preferences.
- 6. ETM 551 Concept Selection 6 Choosing a concept (cont) • Intuition: – The concept is chosen by its ‘feel’. Explicit trade-off criteria are not used. Concept just ‘seems better’. • Multivoting: – Each member of the team votes for several concepts. The concept with the most votes wins.
- 7. ETM 551 Concept Selection 7 Choosing a concept (cont) • Pros and cons: – The team lists the strengths and weaknesses of each concept and makes a choice based upon group opinion. • Prototype and test: – The organization builds and tests prototypes of each concept, making a selection based upon test data. – The team rates each concept against prespecified selection criteria, which may be weighted.
- 8. ETM 551 Concept Selection 8 Choosing a concept (cont) • Decision matrices: – The team rates each concept against prespecified selection criteria, which may be weighted.
- 9. ETM 551 Concept Selection 9 Concept selection for the reusable syringe • There were initially seven distinct concepts for the reusable syringe • How can we choose the best?
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- 14. ETM 551 Concept Selection 14 Concept selection: Structured method • A customer-focused product: – Because concepts are explicitly evaluated against customer-oriented criteria, the selected concept is likely to be focused on the customer.
- 15. ETM 551 Concept Selection 15 Structured method • A competitive design: – By benchmarking concepts with respect to existing designs, designers push the design to match or exceed their competitors' performance along key dimensions.
- 16. ETM 551 Concept Selection 16 Structured method • Better product-process coordination: – Explicit product evaluation with respect to manufacturing criteria improves the product’s manufacturability and helps match the product with the process capabilities of the firm.
- 17. ETM 551 Concept Selection 17 Structured method • Reduced time to product introduction: – A structured method becomes a common language among design engineers, manufacturing engineers, industrial designers, marketing people and project managers, resulting in decreased ambiguity, faster communication, and fewer false starts.
- 18. ETM 551 Concept Selection 18 Structured method • Effective group decision-making: – Within the development team, organizational philosophy and guidelines, willingness of members to participate, and team member’s experience may constrain concept selection. – A structured method encourages decision- making based on objective criteria and minimizes the likelihood that arbitrary or personal factors are allowed to influence the product concept.
- 19. ETM 551 Concept Selection 19 Structured method • Documenting the decision-making process: – A structured method results in a readily understood archive of the rationale behind concept decisions. This record is useful for assimilating new team members and for quickly assessing the impact of changes in customer needs or in the available alternatives.
- 20. ETM 551 Concept Selection 20 Overview of methodology • The concept selection process is based on two methodologies: – Concept Screening – Concept Scoring • Concept screening is just for narrowing the number of concepts • For a small number of concepts, go directly to concept scoring
- 21. ETM 551 Concept Selection 21 Concept Development Funnel concept generation concept screening concept scoring concept testing CONCEPT SELECTION PROCESS
- 22. ETM 551 Concept Selection 22 Concept Screening • Step 1: Prepare the selection matrix • Step 2: Rate the concepts • Step 3: Rank the concepts • Step 4: Combine and improve the concepts • Step 5: Select one or more concepts • Step 6: Reflect on results and process
- 23. ETM 551 Concept Selection 23 Example: Concept Screening CONCEPT VARIANTS SELECTION CRITERIA A B C D E F G REF. Ease of Handling 0 0 – 0 0 – – 0 Ease of Use 0 – – 0 0 + 0 0 Number Readability 0 0 + 0 + 0 + 0 Dose Metering + + + + + 0 + 0 Load Handling 0 0 0 0 0 + 0 0 Manufacturing Ease + – – 0 0 – 0 0 Portability + + – – 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
- 24. ETM 551 Concept Selection 24 Concept Screening • Prepare the selection matrix – Use a reference concept or benchmark • Reference is generally either an industry standard or a straight-forward concept with which the team members are very familiar. • Rate the concepts – Assign relative scores • “ better than” (+) • “same as” (0) • “worse than” (-)
- 25. ETM 551 Concept Selection 25 Concept Screening • Rank the concepts – The sum of all the “better than” “same as” and “worse than” • Combine and improve the concepts – Is there a concept that is generally good but degraded by one bad feature? Can a minor modification improve the overall concept while remaining distinct from the other concepts?
- 26. ETM 551 Concept Selection 26 Concept Screening • Are there two concepts which can be combined to preserve the “better than” qualities while annulling the “worse than” qualities?
- 27. ETM 551 Concept Selection 27 Concept Screening • Select one or more concepts – The number of concepts selected for further review will be limited by team resources (personel, money, and time) – The team must clarify which issues need to be investigated further before a final selection can be made.
- 28. ETM 551 Concept Selection 28 Concept Screening • Reflect on the results and the process – All of the team members should be comfortable with the outcome
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- 30. ETM 551 Concept Selection 30 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.
- 31. ETM 551 Concept Selection 31 Concept Scoring • Step 1: Prepare the selection matrix • Step 2: Rate concepts • Step 3: Rank concepts • Step 4: Combine and improve concepts • Step 5: Select one or more concepts • Step 6: Reflect on results and process
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- 33. ETM 551 Concept Selection 33 Example: Concept Scoring Concepts A DF E G+ Master Cylinder Lever Stop Swash Ring Dial Screw+ Selection Criteria Weight Rating Weighted Score Rating Weighted Score Rating Weighted Score Rating Weighted Score 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
- 34. ETM 551 Concept Selection 34 ... but remember • Subjective criteria may be important • Keep an open mind on improvements • Decide where to include costing • Select elements of aggregate concepts • Apply concept selection throughout the process
- 35. ETM 551 Concept Selection 35 Retail Prices of the Pencils • Twist-Erase Pentel 7.60 YTL • Rotring Tikky II 6.30 • Bic Disney Coloured 4.00 • Techniclick G Pentel 3.80 • Bic Matic Crayon Pencil 1.90 • Script Line Colegial 0.50
- 36. ETM 551 Concept Selection 36 Selection Example Twist-Erase Pentel Rotring Tikky II Bic Disney Coloured Techniclick G Pentel Bic Matic Crayon Pencil Script Line Colegial
- 37. ETM 551 Concept Selection 37 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.
- 38. ETM 551 Concept Selection 38 Summary • All teams use the same method for selecting conceps. • Successful design is facilitated by structured concept selection. • Concept screening uses a reference concept to evaluate concept variants against selection criteria. • Concept screening uses a coarse comparison system to narrow the range of concepts under consideration.
- 39. ETM 551 Concept Selection 39 Summary • Concept scoring uses weighted selection criteria and a finer rating scale. • Both screening and scoring use a matrix as the basis of a six-step process – Prepare the selection matrix – Rate the cfoncepts – Rank the concepts – Combine and improve the concepts – Select one or more concepts – Reflect on the results and the process