Concept SelectionConcept Development ProcessConcept Development FunnelConcept Selection ProcessYour text differentiates between concept screening and concept scoring!Example: Concept ScreeningPowerPoint PresentationSlide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Available Data Controls EvaluationSlide 16Slide 17Slide 18Slide 19Evaluation Scheme for Interval ScalesSlide 21Determine Weighting Factor for Each Design CriteriaSlide 23Remember…CaveatsSlide 26Slide 27Concept SelectionProduct Design and DevelopmentChapter 7Karl T. Ulrich and Steven D. EppingerConcept Development ProcessPerform Economic AnalysisBenchmark Competitive ProductsBuild and Test Models and PrototypesIdentifyCustomerNeedsEstablishTargetSpecificationsGenerateProductConceptsSelectProductConcept(s)Set FinalSpecificationsPlanDownstreamDevelopmentMissionStatementTestProductConcept(s)DevelopmentPlanConcept Development Funnelconcept generationconcept screeningconcept scoringconcept testingConcept Selection Process•Prepare the Matrix–Criteria–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 ImprovementYour text differentiates between concept screening and concept scoring!•Concept screening is used to narrow the number of concepts quickly and to improve concepts.–Your text uses Pugh Concept Selection. We will use a modified technique used by IDEO.–This technique is used when you don’t have a lot of information about your design and you must make decisions.•Concept scoring is used when increased resolution will better differentiate between concepts.–Your text uses an unusual technique. We will use the technique introduced in freshmen design (except that you will use it better.)–Concept scoring should be used when you have more information about your design.Example: Concept ScreeningPrepare the Matrix•Concept screening works best with 20 or fewer criteria. •Criteria should be based upon the PDS – pay attention to customer needs.•You may have to pick the most important criteria to obtain the desired limit.•CriteriaLightweightStablePinch PointsMaintenanceRange of Motion (legs)ComfortForm the Matrix•List the concepts•Problem Definition: –4 year old, handicapped child cannot support her body weight while learning to creep•Options–#1 - Catalog Device Modification–#2 - Crane Suspension Device–#3 - Cart DeviceLightweightStablePinch PointsMaintenanceRange of Motion (legs)Comfort1 2 3Clarify the concepts•Catalog Device Modification: A height adjustable crawler that provides upper body support, but doesn’t keep legs from “kicking out”•Crane Suspension Device: Provides support of child’s body using a spring suspended from a height adjustable support arm•Cart Device: Provides a seat that supports child’s upper body. Also has a plate with bungee cords that limits forward and backward motion of the legs.•Run the Matrix–Compare each option within each row.–Indicate +1, -1, or 0–This is a modification to the Pugh Concept Selection and allows the decision makers to automatically see the best available in each–A description for the rationale behind each ranking should be included.  Catalog Crane CartLightweight 1 -1 1Stable 0 -1 1PinchPoints 1 -1 0Maintenance 0 1 -1RangeofMotion(le gs) 0 -1 1Comfort -1 0 1Totals 1 -3 3Attack negatives and enhance positives•Can you combine portions of one design with another?•Remember our functional analysis - is there a way to change one function and make the design better?3. Consider a material selection problem for a refrigerated food preparation surface material for use in an ice cream store. The surface will be subsequently coated, but hand mixing of ingredients on the surface is needed. Five materials have been identified as possibilities: 1020 Steel, 304 Stainless Steel, 5052 Aluminum, Copper and Bronze. Use the modified concept screening process discussed in class. To help you in this process a table listing the material properties for each criterion is given below.Criteria Units DesiredDirection1020Steel304SS5052ALCu BronzeThickness (in.) less isbetter0.107 0.107 0.407 0.205 0.205Conductivity Btu-ft/(hroF-ft2)higher isbetter27 9.4 80 200 109Diffusivity ft2/hr higher isbetter909 270 3749 6751 3809Hardness Brinnell higher isbetter111 95 47 2 1Yield kips higher isbetter30 110 13 40 37Machinability [0-100] less is better65 90 30 20 20ThermalMassBtu/oF lower isbetter2.93 3.43 7.33 5.45 5.26Criteria DesiredDirection1020 Steel304 SS5052 AlCu BronzeThickness less isbetter Conductivity higher isbetter Diffusivity higher isbetter Hardness higher isbetter Yield higher isbetter Machinability less is better ThermalMasslower isbetter TotalCriteria DesiredDirection1020 Steel304 SS5052 AlCu BronzeThickness less isbetter1 1 -1 0 0Conductivity higher isbetter -1 -1 0 1 0Diffusivity higher isbetter -1 -1 0 1 0Hardness higher isbetter 1 1 0 -1 -1Yield higher isbetter 0 1 -1 0 0Machinability less is better0 -1 1 1 1ThermalMasslower isbetter1 1 -1 0 0Total1 1 -2 1 0Weighted Decision Matrix•Introduced in Freshman Design.•Specify design criterion•Enumerate alternatives•Establish weightings•Determine performance of each alternative for each criteria•Score that performance as indicated by the data that you have.Available Data Controls Evaluation•Some numeric and some quantitative – use interval scales•All numeric = use ratio scalesLet’s return to our matrix for material selection. We have actual numeric data for each item. Let’s see what we would decide if we use ratio scales.Criteria DesiredDirection1020 Steel304 SS5052 AlCu BronzeThickness less isbetter Conductivity higher isbetter Diffusivity higher isbetter Hardness higher isbetter Yield higher isbetter Machinability less is better ThermalMasslower isbetter Total Complete the Matrix Using Ratio ScalesAnswers to the redo of material selectionEvaluation Scheme for Interval ScalesExample of Weighted Decision Matrix Using Interval ScalesTaken from Engineering Design by Dieter and SchmidtA heavy steel crane hook, for use in supporting ladles filled with molten