Rekayasa Kualitas Materi ke 2 Dasar Rekayasa Kualitas

  • Slides: 32
Download presentation
Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop 2003@yahoo. com

Rekayasa Kualitas Materi ke – 2 Dasar Rekayasa Kualitas ekop 2003@yahoo. com

Contents o Basics of Quality by Design n n o Quality Loss Function Quality

Contents o Basics of Quality by Design n n o Quality Loss Function Quality and Process Capability n Process capability

Basics of Quality by Design o Introduction n n o A large amount engineering

Basics of Quality by Design o Introduction n n o 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 )

Basics of Quality by Design Colour density distribution of Sony America and Japan (April,

Basics of Quality by Design Colour density distribution of Sony America and Japan (April, 1979)

Basics of Quality by Design

Basics of Quality by Design

Basics of Quality by Design o o Taguchi’s definition of quality “ the quality

Basics of Quality by Design o o 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 n n Loss as additional manufacturing cost Loss be paid by society

Basics of Quality by Design o Interpretation of loss n Quality loss function (QLF)

Basics of Quality by Design o Interpretation of loss n Quality loss function (QLF) is quantitative evaluation of quality loss due to functional variation m = target y = hasil pengukuran Δo = toleransi Ao = jumlah kerugian

Basics of Quality by Design

Basics of Quality by Design

Basics of Quality by Design o Interpretation of loss n n A quality characteristics

Basics of Quality by Design o Interpretation of loss n n 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 )

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

QLF - Nominal the best ( NTB ) ( One piece ) • A measurable characteristics with a specific userdefined target value. ( Sony TV : 115 ± 20 volts ) • QLF for NTB

QLF - Nominal the best ( NTB )

QLF - Nominal the best ( NTB )

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

QLF – Asymmetric

QLF – Asymmetric

Quality and Process Capability process

Quality and Process Capability process

Quality and Process Capability process

Quality and Process Capability process

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

Quality and Process Capability o Spec limit : fixed engineering limit for the product dimmensions n Cp index n Cpk index o Cpk is an important measure o Cpk as a measure of quality

Quality and Process Capability

Quality and Process Capability

Quality and Process Capability

Quality and Process Capability

Quality and Process Capability Cpk as a measure of quality o The convesional methods

Quality and Process Capability Cpk as a measure of quality o The convesional methods Loss-by-defect = numbers of defect x cost of product = proportion out of spec x total numbe x cost of product o The quality loss function methods Loss-by-dispersion = product x numbers of

Quality and Process Capability Cpk as a measure of quality Example ( Sample 100.

Quality and Process Capability Cpk as a measure of quality Example ( Sample 100. 000 unit )

Quality and Process Capability Cpk as a measure of quality

Quality and Process Capability Cpk as a measure of quality

Quality and Process Capability Cpk as a measure of quality

Quality and Process Capability Cpk as a measure of quality

Quality and Process Capability Cpk as a measure of quality

Quality and Process Capability Cpk as a measure of quality

Case Study ( Tugas – 2 ) A spring is used in the operation

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. 3 oz/in (m=0. 5 oz/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. 25 oz/in versus the loss associated with one at 0. 435 oz/in.

Next Week o The Design Process n Principle of robust design in the production

Next Week o The Design Process n Principle of robust design in the production process n Robust design process n Parameter design