Concept Selection Methods

Chapter 7: Concept Selection

TECH 313Product Design and

DevelopmentMonday, February 2nd 2009

Dr. Seaman

Chapter 7: ConceptSelection

Chapter Table of Contents1. Introduction2. Development Processes and Organizations3. Product Planning4. Identifying Customer Needs5. Product Specifications6. Concept Generation7. Concept Selection8. Concept Testing9. Product Architecture10. Industrial Design11. Design for Manufacturing12. Prototyping13. Product Development Economics 14. Managing Projects

Objectives of this Chapter:

After this lecture and associated activities, students should be able to:

Understand the need for a structured method to select a product conceptKnow the six steps to guide a team through a concept selection processBe able to create a decision matrix spreadsheet for your team’s project containing:

Selection criteriaConcepts related to your team’s project

Concept Selection Defined

“The process of evaluating concepts with respect to customer needs and other criteria, comparing relative strengths and weaknesses of concepts, and selecting one or more concepts for further investigation and testing, or development”

Concept Development Process

Perform Economic Analysis

Benchmark Competitive Products

Build and Test Models and Prototypes

IdentifyCustomer

Needs

EstablishTarget

Specifications

GenerateProduct

Concepts

SelectProduct

Concept(s)

Set Final

Specifications

PlanDownstreamDevelopment

MissionStatement Test

ProductConcept(s)

DevelopmentPlan

Chapter 5 Chapter 5Chapter 7

BOM

Various Methods for Choosing a Concept

External decisionProduct ChampionIntuitionMultivotingPros and ConsPrototype and TestDecision Matrices – YOUR TEAM!

Exhibit 7-5

Concept Development Funnel

concept generation

concept screening

concept scoring

concept testing

Needs for using a Structured Method for Concept Selection

A “structured method” for concept selection:Helps to maintain “objectivity” throughout the concept phase of product developmentGuides the product development team through a critical, difficult and emotional process

Potential benefits for using aStructured Method

Likely to be a customer focused product (customer needs)Helps to create a more competitive product by benchmarking against competitorsBetter product-process coordination with respect to manufacturing criteriaHelps to reduce the amount of time to marketUsing objective criteria helps to facilitate better group decision-making (emotions out)Helps in the process of documenting the decision process

Medical Supply Company

CASE STUDY

Medical Supply Company retains a

Product Design Firm

Opportunity Statement: Develop a “reusable syringe” with precise dosage control for outpatient use

Product sold by a competitor

Concept Selection Example:Reusable Syringe

Two Major Problems with Current Reusable Syringe

CostCurrent product model is made from stainless steel

AccuracyProblems with metering accurate dosage

Company wants to tailor the new product toward to the physical capabilities of the “elderly”

Accurate dosage

7 Needs for Client – End Users

Ease of handlingEase of useReadability of dose settingsDose metering accuracyDurabilityEase of manufacturePortability

Design Concepts = 7 sketches

Each of the 7 concept ideas:Nominally satisfies the customer needs

Lets look at the sketches!

Concept Selection ProcessPrepare the Matrix

CriteriaReference ConceptWeightings

Rate ConceptsScale (+ – 0) or (1–5)Compare to Reference Concept or Values

Rank ConceptsSum Weighted Scores

Combine and ImproveRemove Bad FeaturesCombine Good Qualities

Select Best ConceptMay Be More than OneBeware of Average Concepts

Reflect on the ProcessContinuous Improvement

Example: Concept ScreeningCONCEPT VARIANTS

SELECTIONCRITERIA A 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 + 0Load Handling 0 0 0 0 0 + 0 0Manufacturing Ease + – – 0 0 – 0 0Portability + + – – 0 – – 0

PLUSES 3 2 2 1 2 2 2SAMES 4 3 1 5 5 2 3

MINUSES 0 2 4 1 0 3 2NET 3 0 –2 0 2 –1 0

RANK 1 3 7 5 2 6 4CONTINUE? Yes Yes No No Yes No Yes

Example: Concept ScoringConcepts

A DF E G+

Master Cylinder Lever Stop Swash Ring Dial Screw+

Selection Criteria Weight RatingWeighted

Score RatingWeighted

Score RatingWeighted

Score RatingWeighted

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

Hierarchical Relations –Defining more detail (iterative)

Remember…The goal of concept selection is not to:

Select the best concept.

The goal of concept selection is toDevelop the best concept.

“The process of evaluating concepts with respect to customer needs and other criteria, comparing relative strengths and weaknesses of concepts, and selecting one or more concepts for further investigation and testing, or development”

Group Work for the 3 Product Development Teams

Begin developing a Team Web SiteWhat should be on the front page?

Develop a “decision matrix” to rate concepts for each team

- similar to Exhibit 7-5 (MS Excel file)

Reminders for Next TimeQuiz #5 over Chapter 7 – Concept SelectionLab time for:

Updating of Mission StatementUpdating “decision matrix” to rate concepts for each teamDevelop a “draft” Bill of Materials (BOM) with Low & High Cost

- Estimates (create an MS Excel file -similar to Exhibit 5-10)

Create sketches and rough CAD model for each conceptTeam project web site updates