CONCEPT SELECTION Chapter 9
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Concept Development & Selection 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
These activities can occur throughout the design process!
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• Product concept selection is a decision process, in which the design team selects one or a few product concept for further development.
Challenges • How to choose the best concept of abstraction? • How to embrace all inputs (likings and concerns) from the whole team in the decision process?
• How to make use of good attributes of otherwise weak concept designs?
• How to document the decision process?
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Concept Selection Approaches • External decision
• By use of an external group of customers, clients, etc. • Product champion & intuition
• By an influential member of the development team • Multi-voting
• Asking each member to pick a number of concepts and pick the one with most votes.
• Pros and cons • The team list the strengths and weakness of each concept.
• Prototype and test • Build and test prototype for each concept and select based on the test data.
• Decision metrics • The team rates each concept against selection criteria with varying
importance/weights.
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Issues in the decision process • It assumes that the selection criteria reflect customer’s needs • It assumes that the selection criteria are independent • Manufacturing costs and manufacturability are not included in
the decision • It is better to directly evaluate those independent, simpler
concepts underpinning the design concepts, if they constitute all the product concepts.
• The process of concept selection can be applied to throughout the development process.
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Concept Selection Process
Concept Ratings
Selection CriteriaWinning Concept(s)
Goal: The goal is not to select the best concept but to develop the best concept
by combining and/or refining
Concepts
Screening Stage
Scoring Stage
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Concept Development & Selection Funnel
concept generation
concept screening
concept scoring
concept testing
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Two stages of concept selection • Concept screening
• To quickly narrow the number of concepts and to improve the concepts
• The Pugh concept selection method
• Concept scoring • weighs the relative importance of the selection
criteria • focus on more refined comparisons with respect to
each criteria
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Concept Selection Process
Concept Selection Process
Prepare the MatrixRate ConceptsRank ConceptsCombine and ImproveSelect Best ConceptReflect on the Process
Screening Stage Scoring Stage
Prepare the MatrixRate ConceptsRank ConceptsCombine and ImproveSelect Best ConceptReflect on the Process
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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 the Best Concept • May Be More than One • Beware of Average
Concepts
Reflect on the Process • Continuous
Improvement
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Concept Selection Example
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Reusable syringe
Mission Statement • Product description:
• Reusable syringe with precision dosage control for outpatient use.
• Primary market • Elderly
• Major features: • Accuracy of dose metering • Inexpensive
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Need analysis • Ease of handling • Ease of use • Readability of dose settings • Accuracy of dose metering • Durability • Ease of manufacture • Portability
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7 Product Concepts
Konsep A: Master Silinder (Master Cylinder) • Batas daerah tangkai 1/11 rongga à
penempatan pendorong 1/11 dari posisi alat penyedot
Konsep B: Rubber Brake • Putar alat penyedot 90° untuk
mengatur dosis atau menyimpan penyedot
Konsep C: Roda Bergigi Searah (Ratchet) • Putar alat penyedot 90° dan dorong
ke belakang untuk mengatur dosis. Balikkan untuk memasang penghubung
Konsep D: Plunge Stop (Penyedot Henti) • Putar klep ke depan untuk mengatur
dosis, dorong dengan alat penyedot
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Konsep E: Swash Ring • Untuk mengatur dosis putar cincin
pengatur dosis, tarik alat penyedot dan dorong untuk menyuntikkan
Konsep F: Pengungkit/Tuas • Mengatur dosis dengan mendorong
tuas ke depan dan menyuntikkan dengan mendorong tuas ke belakang
Konsep G: Drill Screw (Sekrup Pemutar) • Mengatur dosis dengan memutar
tombol pengatur dosis, menyuntikkan dengan menekan aktuator
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Concept Development & Selection Funnel
concept generation
concept screening
concept scoring
concept testing
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Concept screening principles
• Be focused on customer needs • Match or exceed competitors’ performance along key dimensions
• Improve the product’s manufacturability • Reduce lead time • Encourage more and effective participation from the design team members
• Have better documentation of the decision process.
Perancangan Produk - Genap 2016/2017
Screening stage
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✔ ✔ ✔ ✔ ✔
Eliminated Concepts
Concepts need to be well-defined PRIOR to concept evaluation! (neither of these concepts made the screening cut)
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Identify “Winning” Concepts
Concept A has highest net score and no “worse than” ratings
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Combine Winning Concepts
Concepts D & F were combined to eliminate “worse than” ratings
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Refine Winning Concepts
Concept G’s scored well but ease of handling was a problem, therefore revise!
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Concept Development & Selection Funnel
concept generation
concept screening
concept scoring
concept testing
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Scoring stage 1. REFINE Pugh’s Matrix
• Criteria – dekomposisi kriteria • contoh: kemudahan penggunaan à kemudahan penyuntikan, kemudahan
untuk dibersihkan, kemudahan untuk diisi • ADD Weightings
2. Rate Concepts • REFINE Scale
• 1 – sangat buruk dibandingkan referensi • 2 – buruk dibandingkan referensi • 3 – sama seperti referensi • 4 – lebih baik dari referensi • 5 – sangat lebih baik dari referensi
• Select “Average” Criteria for Reference • Compare to Reference Criteria
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Scoring stage 3. Rank Concepts
• Sum Weighted Scores
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sj = rijwii=1
n
∑Dimana: rij = nilai konsep j untuk kriteria wi = bobot untuk kriteria I n = jumlah kriteria sj = total nilai untuk konsep j
4. Combine and Improve • Remove Bad Features • Combine Good Qualities
5. Select Best Concepts • May Be More than One
6. Reflect on the Process • Continuous Improvement
Concept Scoring Stage
ConceptsA 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
Generated from Customer Needs – week 1
Need to revisit PUGH Matrix as your team’s knowledge base expands
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Final Winning Concept – DF (Tuas henti/lever stop)
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Final Winning Concept - DF • Concept DF was selected as the winning concept
HOWEVER: • Do not simply select concept was highest rating – conduct a
sensitivity study by varying weights and ratings and examine effect on winning concept rating. Does uncertainty about a particular value have a large impact on the winning concept?
• Team could have decided to go with top two (or more) concepts. Concepts could be prototyped and tested for customer feedback.
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Tips for Concept Development & Selection • When possible, use objective rather subjective criteria • Useful to identify strengths of concepts that do not make it
through screening/scoring stages – could these be incorporated on winning concept(s)?
• Include ease of manufacture, reduced liability, and/or cost as criteria
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TO BE CONTINUED
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