23/04/17 Perancangan Produk - Genap 2016/ CONCEPT SELECTION. Chapter 9

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CONCEPT SELECTION

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Process

Perform Economic Analysis Benchmark Competitive Products Build and Test Models and Prototypes Identify Customer Needs Establish Target Specifications Generate Product Concepts Select Product Concept(s) Set Final Specifications Plan Downstream Development Mission Statement Test Product Concept(s) Development Plan

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.

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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?

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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

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Concept Ratings

Selection Criteria

Winning Concept(s)

Goal: The goal is not to select the best

concept but to develop the best concept

by combining and/or refining

Concepts

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nin

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Concept Development & Selection Funnel

concept generation

concept screening

concept scoring

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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

Prepare the Matrix

Rate Concepts

Rank Concepts

Combine and Improve

Select Best Concept

Reflect on the Process

Screening Stage

Scoring Stage

Prepare the Matrix

Rate Concepts

Rank Concepts

Combine and Improve

Select Best Concept

Reflect 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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Mission Statement

• Product description:

• Reusable syringe with precision dosage control

for outpatient use.

• Primary market

• Elderly

• Major features:

• Accuracy of dose metering

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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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• 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

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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

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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

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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

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Concept Development & Selection Funnel

concept generation

concept screening

concept scoring

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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

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Scoring stage

3. Rank Concepts

• Sum Weighted Scores

s

_j

=

r

_ij

w

_i

i

=

1 n

∑

Dimana:

rij = nilai konsep j untuk kriteria wi = bobot untuk kriteria I n = jumlah kriteria

s_j = 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

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Concept Scoring Stage

Concepts

A DF E G+

Master Cylinder Lever Stop Swash Ring Dial Screw+ Selection Criteria Weight Rating

Weighted Score Rating Weighted Score Rating Weighted Score Rating Weighted 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