Introduction to Statistical Quality Control Introduction to SQC

Introduction to Statistical Quality Control �������� Introduction to SQC 1

Learning Objective n n n ����������� quality and quality improvement ���������� quality ���������������������� �� Introduction to SQC 2

�������� /������ n n n ������������������������� q q q q P Productivity Q Quality C Cost D Delivery S Safety M Method, Management E Environment Introduction to SQC 3

1 -1 Definitions and Meaning of Quality 1 -1. 1 The Eight Dimensions of Quality 1. Performance (will the product do the intended job? ) 2. Reliability (how often does the product fail? ) 3. Durability (how long does the product last? ) 4. Serviceability (how easy is it to repair the product? ) Introduction to SQC 7

1 -1 Definitions and Meaning of Quality 1 -1. 1 The Eight Dimensions of Quality 5. Aesthetics (what does the product look like? ) 6. Features (what does the product do? ) 7. Perceived Quality (what is the reputation of the company or its product? ) 8. Conformance to Standards (is the product made exactly as the designer intended? ) Introduction to SQC 8

Definitions and Meaning of Quality n Quality of design q q q Products ���������� size ��������� Product, ����������� Product ������� (����� )appearance ��� performance ������������� materi als ������������ Product. Introduction to SQC 10

Definitions and Meaning of Quality • Quality of conformance q q q ������������ product ������������� design ������� Factor ��������������� Quality �������� manufacturing processes Introduction to SQC 11

Definitions and Meaning of Quality n n n ��������� Quality of design ��� Quality of conformance ������������������������ ������������������� Introduction to SQC 12

This is a modern definition of quality q q ������� Quality ����������������� variability ������ If variability characteristics of a product decreases, quality of product increases. Introduction to SQC 15

The Transmission Example q q How did the Japanese do this? It leads to the following definition of quality improvement Introduction to SQC 16

• The transmission example ใชประโยชนในการใหคำจำกดความของ improvement • คำจำกดความของ of waste. Quality quality improvement คอ elimination Introduction to SQC 17

Quality Engineering Terminology n Parameter ���������������� �� consumer ������ critical-to-quality ������� q q q Physical : length, weight, voltage, viscosity Sensory: taste, appearance, color Time Orientation: reliability, durability, serviceability Introduction to SQC 18

Quality Engineering Terminology n Quality Engineering q n n Set ���������� , ������������������������� product ����������� product ������ match ����� customer ������� variability ��������� variability ��� material, performance, operator ������� Introduction to SQC 19

Quality Engineering Terminology ������� statistical method ����������� data ����������� ��� 2 ����� n q q Attributes data (�������� ) ������ Countable Data �������������� ����������� Variable data (�������� )����� Measurable Data ���� length, voltage, or 20 Introduction to SQC viscosity

Terminology n ������ specification limit q q n n Lower specification limit Upper specification limit Nonconforming product ����������� material, process ���� part ������� component ���� product ����������� Nonconforming ������� fail ������� specification ��� product Introduction to SQC 22

Terminology n n Nonconforming ����������� Nonconforming �������� Defect product ��� defect ���������������������� product �������� Introduction to SQC 23

Introduction to SQC 24

Statistical Methods n Statistical process control (SPC) q q q n Designed experiments (DOX) q q q n Control charts, plus other problem-solving tools Useful in monitoring processes, reducing variability through elimination of assignable causes On-line technique Discovering the key factors that influence process performance Process optimization Off-line technique Acceptance Sampling Introduction to SQC 25

Statistical Methods Introduction to SQC 26

Statistical Methods A factorial experiment with three factors Introduction to SQC 27

Statistical Methods Introduction to SQC 28