CONCEPT SELECTION - Universitas Brawijayadebrina.lecture.ub.ac.id/.../PerPro-09-Concept-Selection.pdf · 2017. 5. 2. · Concept Selection Approaches • External decision • By

CONCEPT SELECTION Chapter 9

23/04/17 Perancangan Produk - Genap 2016/2017 1

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!


• 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?


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.


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.

23/04/17 5 Perancangan Produk - Genap 2016/2017

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


Concept Development & Selection Funnel

concept generation

concept screening

concept scoring

concept testing


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




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



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


Concept Selection Example


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


Need analysis • Ease of handling • Ease of use • Readability of dose settings • Accuracy of dose metering • Durability • Ease of manufacture • Portability


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


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



concept generation

concept screening

concept scoring

concept testing


23/04/17 17

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


✔ ✔ ✔ ✔ ✔

Eliminated Concepts

Concepts need to be well-defined PRIOR to concept evaluation! (neither of these concepts made the screening cut)


Identify “Winning” Concepts

Concept A has highest net score and no “worse than” ratings


Combine Winning Concepts

Concepts D & F were combined to eliminate “worse than” ratings


Refine Winning Concepts

Concept G’s scored well but ease of handling was a problem, therefore revise!



concept generation

concept screening

concept scoring

concept testing


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


Scoring stage 3.  Rank Concepts

•  Sum Weighted Scores


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

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


Final Winning Concept – DF (Tuas henti/lever stop)


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.


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


TO BE CONTINUED


Documents

CONCEPT SELECTION - Universitas Brawijayadebrina.lecture.ub.ac.id/.../PerPro-09-Concept-Selection.pdf · 2017. 5. 2. · Concept Selection Approaches • External decision • By