Quality Control Concepts

Outline

1. Introduction2. Quality Control3. Quality Assurance4. Total Quality Management5. Quality Tools6. Summary

History

1. Ancient time – skill craftsmen, blacksmith, etc

2. 1700 – Industrial Revolution3. 1776 – Adam Smith – division of labour4. 1790 – Eli Whitney – Interchangeable

parts5. Henry Ford – car industry in USA

The Development

• 1950 – Productivity• 1960 – Productivity + service• 1970 - Productivity + service + Financial Control• 1980 - Productivity + service + Financial Control

+ Quality + Technology• 1990 - Productivity + service + Financial Control

+ Quality + Technology + Direction• 2002 Productivity + service + Financial Control +

Quality + Technology + Direction + Information

Productivity

• Increase output with the same equipment

What is Quality?

1. How can we define it?2. How can we specify it?3. How can we measure it?4. How can we manage it?

Defining Quality

1. English Dictionary1. Essential or distinguishing characteristic2. Good moral, mental or aesthetic

characteristic3. Virtue – degree of goodness or value -

Excellence

Defining Quality (Cont.)

2. TraditionConformal to specification

3. British Standard BS 4778“The totality of features or characteristics of

a product or service that bear upon its ability to satisfy a given need”

4. Fitness for use/purpose

Defining Quality (Cont.)

5. Conformance to customer requirements6. Continuously meeting and improving

upon the agreed customer requirements

“It is the customer that defines Quality”

Reliability

1. A quality product may still fail to satisfy a customer’s expectation if it is unreliable.

2. Reliability is the ability of an item to perform a required function under stated conditions for a stated period of time.

3. i.e. long term quality

Quality must be consider at all stages in the life cycle, as shown below, of a product.

Marketing &Market Research

Requirements&Specification

Design&Development

Procurement

Process Planning&Development

Production

Inspection, testing&Examination

Packaging&Storage

Sales&Distribution

Installation&operation

Technical Assistance&Maintenance

Disposal

Quality Control

• A system for programming and co-ordination the efforts of various groups to maintain or improve quality at an economical level which allows customer satisfaction.

ACTIVITY QUALITYASSESSOR

Input Output Good

Bad

Pros and Cons of QC

Pros:1. Easy to do2. Cheap (short term)3. Manageable

Cons:1. Unreliable, long lead time, big lot sizes2. Inspector takes the mistakes.

Quality Assurance

• All activities and functions concerned with the attainment of quality.

ACTIVITY QUALITYASSESSOR

Input Output

Bad

Good

Pros and Cons QA

Pros1. Easier than QC to find problems2. Problems identify earlier

Cons1. Need skilled labours2. High cost

Correction Cost

Cost of Quality

Total Quality

“A strategy for improving overall performance and quality

competitiveness”

1. Involves every aspect of the business2. Involves every person3. Requires total commitment

Implementation of Total Quality1. The need for an overall business strategy2. Top management commitment3. Adoption of new values and putting the

customer first4. Improving the quality of work life5. Involvement, teamwork and people

empowerment6. Effective data driven problem solving7. Eliminating waste and non-value added

activities

Elements of Total Quality

1. Meeting customer requirements2. Striving to do error free work3. Managing by prevention4. Measuring the cost of non-quality5. Never ending improvement (continuous

improvement)6. Education and training

Achieving Customer Satisfaction

1. Who are your internal and external customers?2. What are their actual needs?3. What are their expectations and measures?4. Do you have the necessary resources to meet

their requirements?5. How are changes in customer requirements

communicated?6. Do you continuously meet their requirements?

Concepts of Quality Control

Quality Assurance - Concepts

Total Quality - Concepts

Tools for Quality Improvement1. FMEA – Failure modes & Effects Analysis2. QFD – Quality Function Deployment3. Capability Studies – tolerance capability of

processes4. Taguchi – minimum change/optimum solution

technique5. Poka Yoke – fool proof devices6. SPC- statistical process control

QFD

Capability Studies

Example of Poka Yoke

Correct Hole

Incorrect Hole

Example of Poka Yoke (cont.)

SPC

Summary

1. Quality is continuously meeting and improving upon the agreed customer requirements.

2. Customer defines Quality.3. Quality Control

ACTIVITY QUALITYASSESSOR

Input Output Good

Bad

Summary (cont.)

4. Quality Assurance

5. TQM is a strategy for improving overall performance and quality competitiveness.

ACTIVITY QUALITYASSESSOR

Input Output

Bad

Good

Summary (cont.)

6. Quality Tools: • FMEA• QFD• Capability Studies• Taguchi• Poka Yoke• SPC