Concept Evaluation

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

How would a group come to consensus? • Agreeing on a process • Supporting the outcome of the process • Merit-based debating • Remaining cool and rational • Emphasis is on discovery Concept Evaluation

External decision Product champion Intuition Pros and cons Prototype and test Decision matrix Methods of Decision-Making

Possible methods of decision making • External decision: Boss • Product champion: A member • Intuition: Gut feelings and vote Concept Evaluation

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

Two-stage methodology • Concept screening • Initial screening (when > 10 concepts) • Concept screening matrix (> 5 concepts) • Concept scoring • Concept scoring matrix (< 5 concepts) Concept Evaluation in ME 492

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

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

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

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 Concept screening matrix

Concept Screening Example

Combine and improve concepts Select promising concepts. Reflect on the process. Concept Evaluation

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 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 Matrix Methods

Concept scoring matrix • The main 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 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 Concept Scoring Matrix

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

Brand-A • Cost: $350, size: 25”, 1 y, 0.28mm, OK looks • Brand-B • Cost: $175, size: 19”, 6 month, 0.19mm, Beautiful • Brand-C • Cost: $430, size: 27”, 2 y, 0.28mm, Very ugly • Brand-D • Cost $275, size 21”, 1 y, 0.15mm, ugly Example

Conversion of Criteria

Evaluations Matrix

Rate and rank concepts • Combine and improve • Select one concept • Consider 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. Concept Evaluation

Was your favorite option selected? If not, here are your options: • Ask for a second round of debating • Study the decision matrix, why did your design score lower than others? • Can you modify your design to address weaknesses • Did the team overlook strengths of your design? Reflect on the results

Concept Evaluation