rekayasa kualitas materi ke – 2 dasar rekayasa kualitas [email protected]

32
Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas [email protected]

Upload: angelica-white

Post on 22-Dec-2015

236 views

Category:

Documents


11 download

TRANSCRIPT

Page 1: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

Rekayasa KualitasMateri ke – 2Dasar Rekayasa Kualitas

[email protected]

Page 2: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

Contents Basics of Quality by Design

Quality Quality Loss Function

Quality and Process Capability Process capability

Page 3: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

Basics of Quality by Design Introduction

A large amount engineering manufacture products in conducting in experiments

Quality by design is one of such engineering methodology

Customer’s perception of quality

( Sony television case in Japan and USA )

Page 4: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

Basics of Quality by Design

Colour density distribution of Sony America and Japan

(April, 1979)

Page 5: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

Basics of Quality by Design

Page 6: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

Basics of Quality by Design Taguchi’s definition of quality

“ the quality of a products is the ( minimum ) loss imparted by the product to society from the time the products is shipped “

What is loss – and who pays for it Loss as additional manufacturing cost Loss be paid by society

Page 7: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

Basics of Quality by Design Interpretation of loss

Quality loss function (QLF) is quantitative evaluation of quality loss due to functional variation

m = targety = hasil pengukuranΔo = toleransiAo = jumlah kerugian

Page 8: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

Basics of Quality by Design

Page 9: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

Basics of Quality by Design Interpretation of loss

A quality characteristics is the object of interest of a product or process

Three types quality characteristics• Nominal the best ( NTB )• Smaller the better ( STB )• Larger the better ( LTB )

Page 10: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

QLF - Nominal the best ( NTB )( One piece )

• A measurable characteristics with a specific user-defined target value. ( Sony TV : 115 ± 20 volts )

• QLF for NTB

Page 11: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

QLF - Nominal the best ( NTB )

Page 12: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

QLF - Nominal the best ( NTB )( Many pieces )

Page 13: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

QLF – Smaller the better ( STB )( One piece )

Page 14: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

QLF - Smaller the better ( STB )( One piece )

Example

Page 15: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

QLF - Smaller the better ( STB )( One piece )

Page 16: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

QLF - Smaller the better ( STB )( Many pieces )

Page 17: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

QLF – Larger the better ( LTB )( One piece )

Page 18: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

QLF – Larger the better ( LTB )( One piece )

Example

Page 19: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

QLF – Larger the better ( LTB )( Many pieces )

n

i iyn

xkyL1

2

11)(

Page 20: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

QLF – Asymmetric

Page 21: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

Quality and Process Capability Capability process

Page 22: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

Quality and Process Capability Capability process

Page 23: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

Quality and Process Capability Spec limit : fixed engineering limit for the product

dimmensions Cp index

Cpk index Cpk is an important measure Cpk as a measure of quality

Page 24: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

Quality and Process Capability

Page 25: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

Quality and Process Capability

Page 26: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

Quality and Process Capability Cpk as a measure of quality

The convesional methodsLoss-by-defect = numbers of defect x cost of product

= proportion out of spec x total numbe x cost of product

The quality loss function methods

Loss-by-dispersion = x numbers of product 2220 )( my

A

Page 27: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

Quality and Process Capability Cpk as a measure of qualityExample ( Sample 100.000 unit )

Page 28: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

Quality and Process Capability Cpk as a measure of quality

Page 29: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

Quality and Process Capability Cpk as a measure of quality

Page 30: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

Quality and Process Capability Cpk as a measure of quality

Page 31: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

Case Study ( Tugas – 2 )A spring is used in the operation of a camera shutter. The manufacturing process

suffers from a degree of variability, in terms of the spring constant (measured in

oz/in), which significantly effects the accuracy of the shutter times. The functional

limits for this spring constant are m±0.3oz/in (m=0.5oz/in), and the average cost for

repairing or replacing a camera with a defective spring is $20.

What is the loss function? Hence, what is the loss associated with producing a spring

of constant 0.25oz/in versus the loss associated with one at 0.435oz/in.

Page 32: Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop2003@yahoo.com

Next Week The Design Process

Principle of robust design in the production process

Robust design process Parameter design