Introduction to SQC

Statistical Quality ControlStatistical Quality Control by- Grant and RS LeavenworthStatistical Quality Control by- Douglas MontgomeryTotal Quality Management by- Dale BesterfieldStatistical Quality Control by- Mahajan

05/01/2023Dept. of Mechanical Engineering

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Successful companies….. Introduction


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Challenges before companies/Engineers…

Achieving PRODUCTIVITY

Introduction

Achieving QUALITY


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What is Quality ??? • Degree to which a set of inherent characteristics fulfils requirement [ISO

9000:2000]

• The American National Standards Institute (ANSI) and the American Society for Quality (ASQ) define quality as: “The totality of features and characteristics of a product or service that bears on its ability to satisfy given needs.”

• Quality means fitness for use• Quality is inversely proportional to variability• Fitness for use ……

Introduction

QUALITY

Quality of design Quality of conformance


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What is Quality ??? Perfection Consistency Eliminating waste Speed of delivery Compliance with policies Doing it right the first time Delighting or pleasing

customers Service

• Suitability• Reliability• Durability• Workability• Affordability• Maintainability• Aesthetics• Economical• Versatility• Satisfaction to customer

Introduction


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Approaches of defining Quality ??? Transcendent Product based User based Manufacturing based Value based

Introduction


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•Competition•Changing customer•Changing product mix•Product complexity•Higher levels of customer satisfaction

Why Quality ???


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• QC means observing the performance and comparing with standards and take corrective measure if there is a deviation

• Quality improvement is the reduction of variability in processes and products.

• Alternatively, quality improvement is also seen as “waste reduction”

• Quality control▫ Establishing standards▫ Ensuring conformance to the standards▫ Corrective measures▫ Preventive measures

Quality control / Improvement


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Quality Control / Improvement• Quality Assurance

▫ This is the prevention of defects before they happen

• Quality Control ▫ This is the detection of

defects after the event

Introduction


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What is Statistical Quality Control ???

• Statistical process control is a collection of tools that when used together can result in process stability and variance reduction

Introduction

Designed to control quality standard of goods produced for marketing.

Exercise by the producers during production to assess the quality of goods.

Carried out with the help of certain statistical tools like Mean Chart, Range Chart, P-Chart, C-Chart etc.

Designed to determine the variations in quality of the goods & limits of tolerance.


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Statistical Quality Control methods• 100% inspection• Acceptance sampling• SQC (Control charts)• Design of experiments

Introduction


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Different Quality PerspectivesTranscendent - “goodness of a product.” Shewhart’s transcendental definition of quality – “absolute and universally recognizable, a mark of uncompromising standards and high achievement.”ExampleS: Rolex watches, Lexus cars.Product based - “function of a specific, measurable variable and that differences in quality reflect differences in quantity of some product attributes.”Example: Quality and price perceived relationship.User based - “fitness for intended use.”Individuals have different needs and wants, and hence different quality standards.Example – Nissan offering ‘dud’ models in US markets under the brand name Datson, which the US customer didn’t prefer.

Introduction


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Manufacturing based - “the desirable outcome of a engineering and manufacturing practice, or conformance to specification.”. Engineering specifications are the key!Example: Coca-cola – “quality is about manufacturing a product that people can depend on every time they reach for it.”Value based - “quality product is the one that is as useful as competing products and is sold at a lesser price.”US auto market – Incentives offered by the Big Three are perceived to be compensation for lower quality.

Introduction

Different Quality Perspectives


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History of Quality methodologyTo know the future, know the past!• F. W. Taylor (Father of scientific management) emphasized on production efficiency

and decomposed jobs into smaller work tasks. Holistic nature of manufacturing is rejected!

• SQC was pioneered by Walter A. Shewhart at Bell Laboratories in the early 1920.• Statistical approaches to quality control started at Western Electric with the

separation of inspection division. Pioneers like Walter Shewhart, George Edwards, W. Edwards Deming and Joseph M. Juran were all employees of Western Electric.

• After World War II, under General MacArthur's Japan rebuilding plan, Deming and Juran went to Japan.

• Deming and Juran introduced statistical quality control theory to Japanese industry (1940).

• The difference between approaches to quality in USA and Japan: Deming and Juran were able to convince the top managers the importance of quality.

Introduction


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History of Quality methodology• Next 20 odd years, when top managers in USA focused on marketing,

production quantity and financial performance, Japanese managers improved quality at an unprecedented rate.

• Market started preferring Japanese products and American companies suffered immensely.

• America woke up to the quality revolution in early 1980s. Ford Motor Company consulted Dr. Deming to help transform its operations.

(By then, 80-year-old Deming was virtually unknown in USA. Whereas Japanese government had instituted The Deming Prize for Quality in 1950.)

• Today we are at Six Sigma conforming age ( 3.2 defect per million parts..!!!)

Introduction


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Total Quality Management• It is the application of

quantitative methods and human resources to improve all the processes within an organization and exceed customer needs now and in future.

Total Quality Management


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Total Quality Management• It is the application of quantitative methods to

and human resources to improve all the processes within an organization and exceed customer needs now and in future.

• Principles and Practices√ Management WILLINGNESS to

yield√ Internal/ external customer FIRST√ Human resource INVOLVEMENT√ Continuously IMPROVE……..√ 40-50% stake on SUPPLIERS√ Uptime, absenteeism, customer

delight

TOTAL QUALITY

MANAGEMENT



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Gurus of Quality Management• Walter Shewhart, developed control chart theory, PDSA cycle theory. In

1931 he wrote a book “Economic control of quality of manufactured product”

• W Edwards Deming, the best known of the “early” pioneers, is credited with popularizing quality control in Japan in early 1950s. Today, he is regarded as a national hero in that country and is the world’s best known quality expert.

• Joseph M Juran, like Deming was invited to Japan in 1954 by the union of Japanese Scientists and engineers. Juran defines quality as fitness for use in terms of design, conformance, availability, safety and field use. He focuses on top-down management and technical methods rather than worker pride and satisfaction. In 1951 he published book “Juran’s quality control handbook”

• Armand Feiganbaum urged QC is necessary to achieve productivity. He emphasized on worker involvement and companywide QC



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• Philip Crosby: author of popular book “Quality is Free”. He argued “doing right at the first time” is less expensive than cost of detecting and correcting nonconformity. He focused on prevention of nonconformance.

• Kaoru Ishikawa, studied under Deming, Juran and Feigenbaum. Adopted TQM to Japanese. Developed Cause and effect chain diagram and Quality circle concepts.

• Genichi Taguchi, developed Loss function concept. His philosophy built on simplification and use of traditional Design of Experiments.


Gurus of Quality Management


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Benefits of TQM• Greater customer loyalty• Market share improvement• Higher stock prices• Reduced service calls• Greater productivity



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Leadership• “Leader is not ‘me’ but ‘we’ ; mission, not my show; vision not

division; and community, not domicile” -Bob eaten

Leadership


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Deming’s Philosophy• Definition of quality, “A product or a service possesses quality if it

helps somebody and enjoys a good and sustainable market.”

Improve quality Decrease cost

because of less rework, fewer

mistakes.

Productivity improves

Capture the market with better quality and reduced cost.

Stay in business

Long-term competitive strength

Leadership


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1. Create and publish to all employees a statement of the aims and purposes of the company. The management must demonstrate their commitment to this statement.

2. Learn the new philosophy.3. Understand the purpose of inspection – to reduce the cost and

improve the processes.4. End the practice of awarding business on the basis of price tag

alone.5. Improve constantly and forever the system of production and

service.6. Institute training7. Teach and institute leadership.

Leadership

Deming’s 14 point Philosophy


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8. Drive out fear. Create an environment of innovation. 9. Optimize the team efforts towards the aims and purposes

of the company.10. Eliminate possesses for the workforce.11. Eliminate numerical quotas for production.12. Remove the barriers that rob pride of workmanship.13. Encourage learning and self-improvement.14. Take action to accomplish the transformation.

Leadership

Deming’s 14 point Philosophy


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1. Lack of constancy of purpose2. Emphasis on short-term profits3. Evaluation of performance, merit rating, and annual reviews of

performance4. Mobility of top management5. Running a company on visible figures alone6. Excessive medical costs7. Excessive legal damage awards

Leadership

Deming’s Seven Deadly Diseases of Management


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Customers’ perception of Quality • Customers’ perception of

quality

Customers’ satisfaction

CUSTOMER

Frontline representatives

Functional operational

areas

Senior managers

CEO

CUSTOMERS’ NEED

(EXPECTATION)

Company offer

CUST

OMER

SATIS

FACT

IO

N


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• Performance• Features• Service• Warranty• Price• Reputation


Customers’ perception of Quality


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Feedback• Comment card• Customer questionnaire• Toll free telephone number• Employee feedback• Customer care



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Maslow’s Hierarchy of needs

Self actualization

Esteem

Social

Security

Survival

Employee involvement


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Quality circle• Teams of workers and supervisors that meet regularly to address

work-related problems involving quality and productivity.• Developed by Kaoru Ishikawa at University of Tokyo.• Became immediately popular in Japan as well as USA.• Lockheed Missiles and Space Division was the leader in

implementing Quality circles in USA in 1973 (after their visit to Japan to study the same).

• Typically small day-to-day problems are given to quality circles. Since workers are most familiar with the routine tasks, they are asked to identify, analyze and solve quality problems in the routine processes.

Employee involvement


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Continuous ImprovementContinuous Improvement


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Pursue quality on two levels,1. The mission of the firm as a whole is to achieve high product

quality. Quality should be talked about in a language senior

management understands. money (cost of poor quality)2. The mission of each individual department is to achieve high

production quality. At operational level, focus should be on conformance to

specifications through elimination of defects- use of statistical methods

Leadership

Juran’s Trilogy


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Quality planning: Process of preparing to meet quality goals. Involves understanding customer needs and developing product features.

Quality control: Process of meeting quality goals during operations. Control parameters. Measuring the deviation and taking action.

Quality improvement: Process for breaking through to unprecedented levels of performance. Identify areas of improvement and get the right people to bring about the change.

Leadership

Juran’s Trilogy


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PDSA cycleContinuous Improvement


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Kaizen • Value added and non- value added work• Muda(waste) over production, delay, transportation, processing,

inventory, waste motion and defective parts• Motion study and cell technology• One piece flow• Documentation • 5-S seiko - arrangement, seiton- orderliness, seiketso- personal

cleanliness, seiso- cleanup , and shitsuke- discipline• Andon display boards• Just In Time• Poka- yoke• Team dynamics

Continuous Improvement

Date post:	17-Feb-2017
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